No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Bond-strength performance of hydraulic lime and natural cement mortared sandstone masonry
Abstract
Flexural bond strength is an important performance characteristic of masonry structures yet there is no guidance for lime-mortared stonework in design codes of practice. This study investigates the bond strength of natural hydraulic lime (NHL) and natural cement mortared sandstone masonry. To this end, the flexural bond strength of masonry couplets, built with mortars of three hydraulic strengths and one natural cement and having a water-content adjusted to achieve a similar consistency, was measured with the bond wrench test. Practical mortar compositions and natural curing conditions were used within the experimental programme. Bond strength was found to be directly related to binder hydraulicity and sandstone pre-wetting time – a positive effect in the case of the former and a negative influence in the case of the latter. Pre-wetting time, however, had a greater influence on the feebly hydraulic lime binder (NHL 2) than on the moderately (NHL 3.5) and eminently hydraulic (NHL 5) lime binders. The results presented will assist in improving our knowledge of lime mortared sandstone masonry and in the development of design guidance.
... As for the matrix, lime 5 and cementitious mortars are the most commonly used ones. Lime-based mortars are usually 6 preferred for masonry structures due to their compatibility, sustainability, and breathability 7 [2,3]. 8 ...
... For details on the procedure followed 15 for preparation of the paste, the reader is referred to [4]. 16 The steel cord used as the reinforcing material was a unidirectional ultra-high tensile steel 17 sheet with a density of 670 g/m 2 and an effective area of one cord equal to 0.538 mm 2 in the laboratory (20°C, 60% RH) under a plastic sheet for a day (named as PL-1); (2) curing 10 of the specimens in the laboratory (20°C, 60% RH) covered with damp cloths and stored under 11 a plastic sheet for seven days (PL-7); (3) curing of the specimens inside a chamber room 12 (20°C, 90% RH) for seven days (RH-7). After that, all the specimens were stored in the 13 laboratory until the testing day. ...
... As opposed to the specimens prepared on dry substrate, the failure of all these specimens was fiber slippage followed by mortar cracking (Fig. 11d-f) in these specimens. This indicates a better bond is formed between the mortar and the brick, in this case [2,25,51,52]. ...
Textile reinforced mortars (TRMs) are innovative sustainable composite materials that recently received extensive attention for strengthening of masonry structures. Understanding the mechanical performance of these composites has therefore been the subject of many recent studies. However, most of these investigations have focused on the mechanical properties of these composites under controlled laboratory conditions, and their performance under field conditions is still unknown. The critical role of substrate preparation and curing conditions on the performance of these repair systems have never been addressed before. To address this gap, this paper presents an experimental investigation on the role of these factors on the performance of two different TRM systems (a steel-based TRM and a glass-based TRM) commonly used for strengthening masonry structures. The results show the importance of these factors and the need for the identification of standard procedures for the application of these systems aiming the optimization of their performance in the field.
... Although the use of NHL was substituted by the extensive use of cement mortars in the 20th century [6], in recent years, it has, once again, become a material of interest, both for restoration purposes (in cases where long-term compatibility with the historic fabric is ensured [7]), as well as a binding material in new eco-friendly constructions [8][9][10]. This renewed interest is on account of (i) its higher compatibility with traditional materials, in relation to cement mortars [3,11,12], (ii) its enhanced behavior in relation to aerial lime mortars (faster and higher acquisition of mechanical strength, earlier carbonation due to lower lime content, ability of hydraulic lime to harden in moist conditions or underwater, lower dimensional changes, etc, [11,[13][14][15]), but also on account of (iii) its enhanced environmental impact, both in relation to its production process [16,17], as well as in relation to its ability to absorb CO 2 from its environment during setting and hardening on account of lime carbonation [13,18]. Additionally, the presence of calcium hydroxide also offers an important potential for selfhealing in the case of micro-cracking occurrence, in the appropriate environment [13,19,20], however at the same time it may be associated with leaching phenomena in certain climates and conditions [21,22]. ...
... Researchers highlight the fact, that by altering these influencing parameters, an NHL mortar can be tailored to exhibit desired characteristics [12,18,27,30]. Regarding NHL2 and NHL3.5 mortars, in the relevant literature, it is noticed that the majority of research is conducted on B/A ratios between 0.13 and~0.25 by weight [4,8,11,15,28,29,31,32,34], while only a few investigate mortars with B/A ratio 0.33 [3,9,33]; furthermore, with the exception of a few studies [3,9,33], usually a relatively high W/ B ratio is applied, close to (or even higher than) 1. It should be noted that important research has also been conducted regarding the improvement of NHL mortar characteristics with the addition of fine aggregates [30,32], as well as pozzolans [26,35]. ...
... Comparing the flexural strength of the NHL2 mortars investigated in this study with the respective values presented in relevant literature [3,11,15,28,29], it is noticed that all fabricated mortars present intermediate values to those found in the literature (Fig. 5). Regarding the NHL3.5 mortars (Fig. 6), it is noticed that NHL3.5_25 and NHL3.5_30 present higher flexural strength than other NHL3.5 mortar mixes, as found in the relative literature [8,15,[31][32][33][34], at all ages, while NHL3.5_20 ...
Natural hydraulic lime (NHL) is a material which has received increased interest in the past decade as a binder for the production of mortars. The renewed interest of researchers and builders in natural hydraulic lime is attributed to its enhanced compatibility with many traditional materials, as well as the fact that it is an environmentally friendly material, especially in relation to modern cement. In the present study, two different types of natural hydraulic lime mortars are studied, using NHL2 and NHL3.5 as binder (in accordance to the new classification EN 459-1:2010) and the same river sand, while the influence of different binder to aggregate ratios on mortar characteristics is also investigated. Fresh mortar characteristics are examined immediately after mixing, while hardened mortar characteristics are evaluated at different mortar ages. Specifically, the mechanical performance of the mortars is evaluated through flexural and compressive strength tests, as well as the dynamic modulus of elasticity, which is estimated through ultrasound pulse velocity measurements. Physical performance of the mortars is investigated through the examination of the pore network structure characteristics, via mercury intrusion porosimetry measurements, and through the examination of hygric characteristics, via water absorption tests. The binder to aggregate ratio seems to play an important role in the development of the mechanical and physical characteristics of the mortars, while it influences mortar properties differently according to the type of the binder.
... The use of natural hydraulic lime as a binding material for the production of mortars is traced back to antiquity and was frequent in areas where the local limestone naturally contained impurities [1][2][3][4]. In the 20th century the use of lime (aerial and hydraulic) in construction reduced, as the use of cement became more widespread [5,6]. In recent years, the negative effects deriving from the inappropriate use of incompatible cement-based mortars, as a conservation and restoration material in built heritage, have renewed researchers' and practitioners' interest in lime-based mortars [3][4][5][6][7][8]. ...
... In the 20th century the use of lime (aerial and hydraulic) in construction reduced, as the use of cement became more widespread [5,6]. In recent years, the negative effects deriving from the inappropriate use of incompatible cement-based mortars, as a conservation and restoration material in built heritage, have renewed researchers' and practitioners' interest in lime-based mortars [3][4][5][6][7][8]. ...
... Thus, natural hydraulic lime is a hybrid binder, partially aerial and partially hydraulic in nature [4]. This allows for NHL mortars to harden both in standard air dry conditions and in high humidity environments, through the various reactions which take place during hardening (hydration and carbonation), providing an additional advantage regarding their use [5,6,[9][10][11]. The Ca (OH) 2 present in the initial material, in addition to the Ca(OH) 2 , present as a product of the hydration reaction, provides a great potential for the initiation of an autogenous, self-healing mechanism, when needed [11,12]. ...
In recent years, the study of high hydraulicity natural hydraulic lime (NHL5) mortars has been in the focus of many researchers, as it is considered a compatible, eco-friendly binding material, which can be used both for the restoration of culturally and historically significant structures, as well as for the construction of contemporary buildings. In the present study, artificial neural networks (ANNs) are used, aiming to simulate and map the development of NHL5 mortars’ characteristics, such as compressive strength (CS), ratio of compressive to flexural strength (CS/FL) and consistency (CO), for selected mortar mix parameters, namely the binder to sand ratio (B/S), the water to binder ratio (W/B) and the maximum diameter of the aggregate (MDA) for different mortar specimen ages (AS). To this purpose, databases were developed, integrating experimental data from the international literature. Experimental verification of the developed ANN models revealed satisfactory fitting between theoretical and experimental results. This research highlights the potential of ANNs as a tool which can assist in mortar design and/or optimization, while mapping the development of mortar characteristics can assist in revealing the influence of the different mortar mix parameters on each characteristic. Furthermore, by combining the results of the three developed ANNs (CS, CO, CS/FL) targeted multi-parametric design of mortars can be assisted through a novel approach.
... The textile is usually made of glass, steel, basalt, carbon, or even natural fibers (e.g., hemp, flax), and matrices are either cementitious or lime-based. Lime mortars are suitable for strengthening masonry and historical constructions because of compatibility aspects, sustainability issues, breathability, and the capability of accommodating structural movements [33][34][35][36][37][38]. ...
... As opposed to the specimens prepared on dry substrate, the failure of all these specimens was fiber slippage followed by mortar cracking (Fig. 5-33) in these specimens. This indicates a better bond is formed between the mortar and the brick, in this case [33,195,215,216]. ...
Textile-reinforced mortars (TRM) have recently received significant attention for the externally bonded reinforcement (EBR) of masonry and reinforced concrete structures. They are comprised of a high-strength mesh bonded with an inorganic matrix. The meshes are composed of bidirectional yarns containing basalt, carbon, alkali-resistant glass, aramid or PBO yarns, or unidirectional textiles containing ultra-high tensile strength steel cords. Textiles are bonded using matrices such as cement, lime, or geopolymer mortars. In scientific and technical literature, there is also a use of other names and acronyms: fabric-reinforced cementitious matrix (FRCM) and steel-reinforced grout (SRG) when using steel fabrics.
Due to the novelty of this solution, several issues such as durability and long-term performance are unknown to a large extend, and relevant test standards and design methods do not exist yet. To address this gap, this study presents a multi-level comprehensive experimental and analytical investigation on the mechanical performance of TRM composites to strengthen existing masonry structures. The purpose is to provide new insights into the effect of critical environmental conditions on TRM-masonry at different scales and correlate material degradation to the global structural performance by performing accelerated aging tests on TRM-masonry systems. Hence, micro (fabric-to-mortar bond), meso (TRM-to-substrate bond), and macro (TRM tensile response and in-plane and the out-of-plane response of TRM-strengthened masonry) response of TRMs are combined and investigated in-depth under natural environmental and freeze-thaw (FT) conditions. Steel and AR-glass-based TRM composites made with hydraulic lime-based mortar are used for strengthening clay brick-based masonry panels.
The results show that the long-term behavior of TRM composites for different ages is significantly dependent on the mortar and fiber combination and, therefore, can change notably between different TRM solutions. It is also observed that lime-based TRMs cannot reach their total mechanical properties under indoor conditions even after three years. Outdoor conditions lead to better curing of the samples and achieving significantly higher mechanical properties in these composites. However, it can also lead to a significant deterioration at later ages. The results also indicate that the freezing-thawing exposure conditions considered in this study do not have detrimental effects on the mortar strength. However, the fiber-to-mortar bond behavior can deteriorate, because the level of deterioration depends on the fiber type, embedded length, and fiber configuration.
... The IRA value determined for the analyzed clinker units was close to the lower limit of the range, characterizing the masonry units as middle-absorption or middle-suction units. The values obtained indicate that the masonry units can absorb moisture from fresh mortar at a rapid rate and may impair bond strength [56]. ...
... Of course, as is well known, a great many factors affect the values of bond strength [33,52,59], including mortar physic-mechanical parameters [7,53,56,60,61]. In the processes presented and analyzed below, the value of IRA is, of course, very important, but so is the connection with the porosity of masonry elements (number of open pores and total number of pores) and the size and number of capillaries [62], also in relation to mortar, which is equally important [50]. ...
In the present study, experimental investigations on the influence of mixing water content used for the preparation of mortar mix using factory-made dry-mix mortar dedicated to bricklaying with clinker masonry units are presented, as well as the curing time on flexural bond strength of masonry made of these two materials. The flexural bond strength was tested using the “wrench test” method. The masonry tests specimens were prepared using three volumes of mixing water as follows: 4.0 L (the value recommended by the mortar manufacturer); 4.5 L; and 5 L of tap water per one 25 kg bag of dry pre-mixed mortar. The influence of the mixing water content was analyzed in relation to curing time. All masonry specimens were tested in four series after 9, 14, 21, and 28 days of sample curing. The results showed that the use of 6 and 18% more mixing water than recommended by the manufacturer (4.5 and 5 L per bag) adversely affected flexural bond strength. Moreover, for all three mixing water amounts, it was found that the maximum values of bonding strength were reached after 9 days of curing, which decreased over time. The largest decreases (30–40%) were recorded after 14 days. After 21 days, these values continued to decrease, but more slowly. The final value of the ratio of bond strength to flexural strength of the mortar was similar for all amounts of mixing water and for the 28-day curing time, it oscillated around 0.2.
... This paved the way for the development of new building materials for construction including Portland cement [10][11][12][13]. Since, 20th century, Portland cement gained importance and was used widely all over the world [14][15][16][17]. Portland cement had overcome the drawbacks in lime like slow setting time, low mechanical strength, high porosity, high water absorption etc. ...
... It was observed from previous studies that hydraulic lime mortars have a good compatibility with heritage mortars [29,30,32,[49][50][51][52][53][54]. The main attributes corresponding to the usage of hydraulic lime mortars are low shrinkage values [17,30], sufficient permeability thereby breathability, resistance to salt erosion [29], permitting proper water transfer and evaporation [18,32], low stiffness allowing movements of structures but comparatively higher strengths than aerial lime mortars for achieving overall durability [18,30,50]. In India, due to wide usage of cement in construction activities, commercial production of hydraulic lime binders is not available. ...
Lime was one of the predominantly used construction materials during ancient times world over. However, its prominence was repressed with the invention of cement. Though cement was found to be useful in many applications in construction industry, it was ascertained detrimental as a repair material particularly for heritage structures. The primary reason is the incompatibility of cement with the substrate (ancient lime) and masonry units in terms of mechanical and durability characteristics. From the previous investigations on ancient mortars performed at UNESCO heritage listed Ramappa temple and two other temples in Warangal fort, the binder was found to be lime and the fine aggregate used was siliceous sand. Also, the binder in the ancient mortars was in between weak and moderate hydraulicity. In view of this and some specific interests, it was thought that lime can be a better repair material. Since, lime characteristics depend on its source and location, in the present study, physical, mechanical and durability characteristics of two aerial limes (Lime-I and Lime-II) based mortars with replacements of fly ash/Ground Granulated Blast Furnace Slag (GGBS) from 0 to 75% were focused. In the present work, 1:3 and 1:1 mix proportions of lime-based mortars were studied for mechanical and durability studies. Among the binders, Lime-fly ash and Lime-GGBS binders required lower water content than pure aerial lime binders (Lime-I and Lime-II) for attaining similar consistency. Lime-GGBS binders exhibited faster setting characteristics than lime-fly ash binders and pure aerial lime binders (Lime-I and Lime-II). Among the mortars considered, Lime-II based 1:1 proportion mortar with 66% replacement level of lime with GGBS showed highest mechanical strength properties with compressive and transverse strengths of 9.02 MPa and 2.46 MPa respectively. It showed least porosity, water absorption and rate of strength loss to alkali (NaOH) immersion with 31.23%, 18.52% and 9.42% respectively. However, lower capillary absorption of 0.39 Kg/(m².min0.5) was attained for a Lime-II based 1:1 proportion mortar with 75% replacement level of lime with GGBS. All the lime-based mortars exhibited good thermal resistance. Salt crystallization resistance was better exhibited by 1:1 mix proportion lime-GGBS based mortars. However, least drying shrinkage of 1.02 mm/m after 70 days was obtained for Lime-II based 1:3 proportion mortar with 75% replacement of lime with fly ash. Lime-GGBS based mortars specifically with 66% replacement of lime with GGBS exhibited better mechanical and durability characteristics. Also, these mortars showed close resemblance with the physical properties of ancient mortars like porosity and were made of similar materials like lime and siliceous sand, thereby establishing their potential as repair material for heritage structures.
... In the beginning of the twentieth century, the use of lime-based mortars was substituted extensively by cement-based mortars [1,2]. Cement mortars, although presenting positive qualities (fast setting and hardening, high mechanical performance at early ages), proved to be inappropriate for use in restoration projects, as the different physicochemical and mechanical characteristics they present, in relation to traditional building materials, led to the development of stresses, with negative effects on the historical building materials and the longevity of the historical structures and monuments where they were applied [1,[3][4][5]. ...
... Thus, in recent years, the requirement for compatible and performing restoration mortars has emerged, and researchers have shifted their attention to the re-discovery of traditional mortar production techniques [e.g. [1][2][3][5][6][7][8], as well as methodologies to design compatible and performing restoration mortars [3,[9][10][11][12]. ...
Designing mortars for restoration work is a crucial step in any conservation project. Mortars are complex, composite materials and their characteristics are dependent upon the raw materials used, as well as several design parameters. Especially in the case of monument protection, it is important to design a mortar with required characteristics to ensure its compatibility in relation to the historical materials, and its effectiveness in terms of the restored monument’s mechanical performance. In this chapter, first, a discussion is made on the effect of the design parameters and raw materials of a mortar on its characteristics, taking into account international literature. Following this, an interdisciplinary methodological approach is presented, focused on the design of restoration mortars, considering the characteristics of the historical materials of the monument, the environmental stresses it is subjected to, and the vulnerability of the structure to mechanical stresses. This approach considers any architectural or geometric characteristics which may set limitations to which the restoration mortar must abide by. Principal component analysis (PCA) is used to correlate and examine mortar characteristics within a combined space, where compatibility and performance are simultaneously achieved.
... Additional experiments are required for the determination of the properties of the bond. These incorporate tensile and shear strength tests, as for example those conducted in [4], [3] and [99]. ...
... Equation 4.19 can be further simplified in cases when the initial trial tangential force at the zero load step is zero. ...
The dissertation of Georgios Michaloudis was submitted on October 17, 2018 at the Bundeswehr University Munich (Universität der Bundeswehr München) by the Faculty of Civil Engineering and Environmental Sciences, adopted on February 13, 2019. The oral exam took place on March 12, 2019.
Joint supervisions:
1. Univ.-Prof. Dr.-Ing. habil. Norbert Gebbeken
2. PD Dr. habil. Alexander Konyukhov
3. Professor Vissarion Papadopoulos
This thesis addresses the behavior of interfaces between contacting bodies and provides strategies for their incorporation into numerical models within the finite element method. In a first step a typical example from civil engineering involving interfaces, the unreinforced masonry wall, will be studied. Extreme loading resulting from explosions has been chosen as external loading conditions and specific simulation strategies in order to capture the formation of damage are proposed. The proposed models cover the formulation of an appropriate material law and of the equation of state based on experimental data, as well as modeling strategies with an eye on the specific characteristics of the behavior of the interfaces and of the entire wall under extreme loading conditions.
In a second step the focus lies on the development of a complete three dimensional frictional contact formulation for the modeling of interaction phenomena which occur on the interface of contact surfaces. A fully covariant approach is employed for the description of the contact conditions. A Surface-to-Surface algorithm based on a penalty regularization is implemented. Tools from differential geometry are employed in order to describe the geometry of the surfaces in an exact manner. A thermodynamic framework for dissipative processes is formed for the definition of appropriate material laws, which are then incorporated into the contact formulation. The proposed material model is based on experimental results and is derived as a simple elastoplastic associative constitutive law with softening. The validation of the developed formulations is performed based on the experiments. A return mapping scheme is applied for the definition of the stick-slip transition and for the computation of the correct tangential traction. This traction is then used in the consistent linearization which results in a symmetric sti�ffness matrix not only for sticking but also for sliding, since the non-associative nature of the Coulomb friction law is abandoned. By adopting the fully covariant description, which is applied by introducing appropriate local coordinate systems, the sti�ffness matrix has a clear form allowing simplifications. This formulation results in an interface finite element, which consists of 8 nodes in the case of linear or of 18 nodes in the case of quadratic finite element approximations. The thesis closes with the generalization of the contact formulation for arbitrary anisotropic surfaces. The case of anisotropy resulting from inherent structural characteristics of the interface is thoroughly discussed. It is shown that by taking advantage of a fully covariant description suitable constitutive laws can be introduced straightforwardly. This issue is of great importance when experimental results are available.
... As for the matrix, cementitious or lime-based mortars are usually used. Lime-based mortars are preferred for application to masonry and historical structures due to their compatibility, sustainability, breathability and capability to accommodate structural movements [7][8][9]. ...
... Based on a literature review [7,8,36,38,39], specimens are demolded after 24 hours of preparation and are placed in a damp environment for seven days. After that, specimens are stored in the lab environmental conditions (20°C, 60% RH) until the test day (for 60 days of mortar curing). ...
Textile-reinforced mortars (TRM) have recently received significant attention for the externally bonded reinforcement (EBR) of masonry and reinforced concrete structures. The fiber-to-mortar bond, the TRM-to-substrate bond, and the mechanical properties of the TRM constituents have a fundamental role in the performance of this strengthening technique and therefore require special attention. Despite this importance, only few investigations are devoted to characterization of the single fiber-to-mortar bond response in these systems.
This paper, as an step towards addressing the fiber-to-mortar bond, presents a combined experimental and analytical investigation on the effect of test setup on the pull-out response and bond-slip laws in TRM composites. Three different pull-out test setups, consisting of one pull-pull and two pull-push configurations, are developed and investigated for characterization of the single fiber-to-mortar bond behavior. The experimental and analytical results are critically discussed and presented and bond-slip laws are extracted for each test setup.
... By using the waste materials, in the construction industry, the natural resources are kept in a sustainable way [2]. Previous studies have examined the properties of masonry, including its compressive strength and stress-strain characteristics, as well as its components, such as mortar and brick [3][4][5][6][7]. ...
Masonry is possibly the primary construction element currently in widespread use throughout the world. Load-bearing masonry building is prevalent in developing countries for home construction. When properly constructed, masonry is frequently a more cost-effective and energy-efficient alternative to reinforced concrete for wall building. In addition to performing the dual roles of supporting weight and enclosing space, structural masonry boasts a high level of fire resistance, thermal and acoustic insulation, and exposure protection. The remarkable durability and low maintenance costs are further evident benefits. Masonry has a significant role in building construction, particularly in structures, as it is regarded as the primary component of the building. The eco-friendly solid block is prepared by adding the following by-products like coal ash, granite powder, olivine sand etc., all these ingredients used for manufacturing the solid block are waste materials from various industries. Thus, extensive testing is necessary to assess their load carrying capacity and secant modulus accurately. Masonry prisms were developed with five-layer solid blocks and tested for their stress-strain characteristics and secant modulus and the test outcomes were compared with conventional fly ash cement blocks. Eco-friendly solid blocks offer a persuasive substitute for ecologically conscious approaches to building by preserving structural integrity and functionality while promoting sustainability.
... When the concentration reaches 1.4 mol⋅L − 1 , there is a noteworthy increase in the carbonation degree of 10 days (49%, 27% and 24% at 0-5 mm, 10-15 mm and 15-20 mm respectively) and 28 days (88%, 43% and 36% at 0-5 mm, 10-15 mm and 15-20 mm, respectively), particularly in the interior region (Fig. 4). This results in a significant improvement in mechanical strength [32][33][34]. It is evident that the addition of ammonium carbonate is beneficial for enhancing the early-age mechanical strength of lime mortars. ...
Ammonium carbonate was used as the carbonation accelerator for air-hardening lime mortars in this study. Various analytical methods, including XRD, IR, TGA-DSC and SEM were employed to access the phase transformation , degree of carbonation and microstructural features of the lime-based mortars. The paper explores the correlation between the mechanical strength, microstructure of cured lime mortars and the composition/ carbonation degree with the crystallization behaviors in Ca(OH)2/CaCO3 binders. The results indicate that ammonium carbonate significantly accelerates the carbonation reaction and increases the early mechanical strength of air-hardening lime mortars. The mechanical strength of these modified lime mortars can be comparable to that of natural hydraulic lime (NHL). The aggregation behaviors of nano-CaCO3 under kinetic control, are believed to contribute much to the compact pore-structures and robust mechanical strength of lime mortars. This viable accelerating carbonation method holds promise for enhancing the properties of various lime-containing building materials in conservation and modern buildings.
... By considering factors such as masonry unit properties [12], mortar composition, joint geometry [13], and construction techniques, builders can optimize the bond strength and ensure the long-term performance of masonry assemblies [14]. The bond strength is influenced by factors such as the type of loading (compression, tension, shear), exposure conditions (moisture, temperature variations), and the overall structural design [15]. Numerous studies have investigated the bond strength of masonry. ...
Bond strength is a crucial factor that impacts the performance, structural reliability and stability of masonry constructions. This paper aims to examine the efficacy of various masonry unit and mortar combinations and their bond strength thereby, evaluating their adhesion performance. It experimentally analyzes two masonry unit types paired with two mortar combinations. One is the traditional clay brick and the other is an alkali activated flyash based brick. Alkali activated flyash bricks and mortars use flyash as a sole binder, activated with popular alkalis, thereby reducing carbon footprints compared to cement manufacturing. Two types of mortar used are conventional cement mortar and alkali activated flyash mortar. Bonded prisms were tested to determine the compressive, tensile, shear, and flexural bond strengths. The results revealed significant variations in bond strength across different combinations of masonry units and mortar. Notably, it was observed that alkali-activated bricks bonded with alkali-activated mortar exhibited higher bond strength, compared to conventional cement mortar. These findings provide valuable insights in assessing the compatibility between masonry units and mortar, highlighting the potential of this technology for sustainable construction practices.
... These two loading types from the compressive strength test [21] of masonry prisms give the elasticity properties [22]. In addition to the compressive strength, shear strength [23] and bond strength [24] are also the chief parameters that need to be quantified for effective analysis of brick-mortar interface binding. The bonding behaviour is determined by the water-cement ratio [25] and the percentage of replacement materials. ...
In the construction sector, cement plays a vital role in all the members and components in which
it acts as a binder and strength-dependent material. The production of cement material emits a
large quantity of CO2 gas, which has been the main cause of global warming and other
environmental and health issues. To overcome this issue, low carbon or net-zero cement
production and utilization is a necessity, which equally satisfies the binder ability of conventional
ordinary Portland cement (OPC). The fly ash from thermal power stations that is deposited in the
yard is the most frequently used replacement material for cement. Due to its excellent pozzolanic
properties, this fly ash can be utilized in place of binding materials in the building industry to
achieve carbon neutrality. In this investigation, fly ash is used to prepare net-zero mortars in place
of a significant amount of cement. Fly ash is utilized both in its natural form and after being ground
into tiny particles for increased reactivity and effectiveness. The test for compressive strength
allows for a detailed examination of the mechanical properties by altering the ratio of water to
cement with and without the use of super plasticizer (SP). The best mortar is fine F fly ash (FFFA),
which is made using a water-to-cement ratio of 0.4 + 1% SP. To validate the outcomes of this
investigation, a characterization study of the improved mortars was examined.
... Therefore, several authors proposed multiple failure theories for brick masonry under compression, emphasizing the importance of bond strength in defining the masonry strength. According to these theories, if the brick-mortar bond is weak, the failure of the masonry prism is mainly related to the failure of the brick-mortar bond [37][38][39][40]. Since strength and stiffness are required to determine the mechanical response of masonry structures [41][42][43], empirical formulations are required for assessing existing, and new masonry buildings [44][45][46][47]. ...
... However, literature studies have examined the change in physical, chemical, and mechanical properties of mortars made with lime powder up to a year after curing (Barr et al., 2015;Gunasekara et al., 2020;Sáez-Pérez et al., 2021) that helps in building the knowledge and prospectus of the field concerned. ...
This research work focuses on the investigation of the possible roles of hydrated lime on the properties of hardened mortars. In this study, the effect of the hydrated lime mortar has been investigated using response surface method (RSM) and artificial neural network (ANN). This research paper also summarizes the experimental results obtained from the investigation of mortar samples with 10, 20, 30, and 40% of hydrated lime that replaced cement. The mortar mixes have been prepared in a ratio of 1:3 and a w/c ratio of 0.4, which has been taken as the standard mix ratio. In experimental work that has been carried out, the compressive strength is measured post 28 days. RSM method has been used to predict the properties of mortar, which has been taken as standard and the mortars, with the hydrated lime to compare the experimental data. RSM model has shown an accurate result (R2 ≥ 0.99), in predicting the mechanical properties of the mortars. The same experimental research design has been used to train the neural network. ANN model has also supported by showing an accurate result (R2 ≥ 0.99), in predicting the mechanical properties. Predictions with root-mean-squared error (RMSE), the mean absolute error (MAE), and the model predictive error (MPE) have been carried out to test the ability of both methodologies which have been done and compared. As a result, the RSM and ANN technique has been validated for the use in both response estimation and effective parameter identification. Furthermore, the RSM and ANN technique has also been used to perceive the optimal parameters.
... Natural hydraulic lime soil, especially natural hydraulic lime with less hydraulic components, is easily affected by external factors, such as carbonation [1], chemical corrosion [2], freeze-thaw cycles [3]; carbonation, chemical corrosion, and freeze-thaw cycles can cause insufficient durability. Most earthen ruins are in the open environment, and their soil is susceptible to acid rain and acidic substances from groundwater. ...
Natural hydraulic lime soil has good mechanical properties; as an earthen ruin restoration material, its durability is insufficient. Despite natural hydraulic lime being a topic that has been studied for several years from different researchers, it has not yet been fully considered for the improvement of durability. This work aims to experimentally investigate the enhancement of the durability properties of hydraulic lime-based. The performance of natural hydraulic limestone by adding sodium methyl silicate and organic silicon is examined and the effect of adding sodium methyl silicate on its performance and microstructure is studied. The 6%, 10%, and 15% lime–soil comparison test blocks of sodium silicate were compared with different lime–soil comparison test blocks not mixed with sodium methyl silicate; in addition to compression resistance, shear resistance, water absorption, and erosion resistance, dry–wet cycles were carried out, as well as microstructure testing and analysis. The results show that the addition of sodium methyl silicate enhances the compressive strength of hydraulic lime-modified soil, reduces its saturated water absorption, reduces its shear strength, improves its resistance to dry and wet cycles, and forms on the surface of the modified soil particles. The hydrophobic layer further improves its erosion resistance and water resistance. When the sodium methyl silicate content is 0.3%, the natural hydraulic lime soil has good mechanical properties and good durability, which is the optimal ratio.
... Values were under the common values for historic mortars, for which a minimum is about 0.8 MPa [67] except for the control sample. However, as a function of the support in a search of compatibility, repair mortars have been found of lower strength, even lower than the results achieved [56,68,69]. As aforementioned, the increase of the liquid content in samples notably increased porosity, inducing a reduction of the strength. ...
In search of compatible materials to speed up the strength and carbonation in lime mortars, nanoparticles show significant potential. This research explores the mechanical and physical characteristics of air lime mortars with silica sand and two types of dispersions based on nanoportlandite (nP) and nanosilica (nS) used as additions according to different curing conditions. Thus, samples kept under laboratory conditions (23 °C, 40% RH and 700 ppm CO2) and in a climatic chamber (20 °C, 75% RH and 1600 ppm CO2) were tested to understand the influence of environmental conditions in these types of systems.
Results
showed that nanoparticle dispersions have a notable effect on the mechanical and hydric performance of lime mortars as a function not only of the components but also of the curing conditions. Solvents modified the water/binder ratio with an increase of microporosity and pore volume, which negatively affected mechanical and hydric properties. However, microporosity is reduced with nanoparticles which favours the deformation capacity of the mortars. Moreover, some interesting findings arise regarding the effect of solvent and the morpho-structural properties of calcium silicate hydrate (C–S–H). Differences in terms of morphology, fibre size, flexibility or content stand out, attending to the type of nanoparticles and the curing conditions. Air lime mortar with one part of nanoportlandite and 2 of nanosilica achieved the highest rates of carbonation and hydration products under chamber conditions compared to those located in laboratory conditions.
... Physical properties of the Sikadur-30 mortar and the Sika CarboDur M-514 strip[33][34][35]. ...
Nowadays, there are several existing masonry arch structures which are usually protected. Therefore, the maintenance and determination of their load-bearing capacity is a very important issue. Consequently, it is necessary to understand the behaviour of these structures, but the investigation of an old structure can cause difficulties. Nevertheless, a lot of tests can be performed on a smaller model under laboratory conditions. It is easier to understand their structural behaviour and determine the parameters that significantly influence the load-bearing capacity. It also gives the chance to build and verify a numerical model that can be used to model existing structures. In this research, destructive tests of small scale stone masonry arches were performed under laboratory conditions. The analyses were carried out with and without reinforcement to determine the differences in structural behaviour, load-bearing capacity, and failure type. For the tests, carbon fibre reinforced polymer (CFRP) plates were used to strengthen the arch. The properties of the building materials of the stone masonry arches were tested. The paper presents the results and experiences of the construction and the loading of small scale masonry arches. Furthermore, it gives a comparison between the behaviour of reinforced and unreinforced structures.
... The textile is usually made of glass, steel, basalt, carbon, or even natural fibers (e.g., hemp, flax), and matrices are either cementitious or lime-based ones. Lime mortars are suitable for strengthening masonry and historical constructions because of compatibility aspects, sustainability issues, breathability, and capability of accommodating structural movements [4][5][6][7][8][9]. Cementitious matrices are usually used to strengthen structures stronger than traditional masonry constructions [10][11][12][13]. ...
Textile-reinforced mortar (TRM) composites, composed of textile fibers embedded in an inorganic matrix, have been found to be a sustainable solution for strengthening of existing masonry and concrete structures. Despite the extensive recent attention in understanding the mechanical performance of these composite, their long-term performance and durability remain basically unknown. To address this gap, this paper presents a comprehensive experimental and analytical study on the changes in the mechanical response of these composites across scales (from material characterization to bond and tensile tests of TRM composites) under indoor and outdoor conditions. For this purpose, steel and glass fibers with lime-based mortar are used to investigate the pull-out response and the tensile behavior of TRM composites. The results show that the long-term behavior of TRM composites for different ages is significantly dependent on the mortar and fiber combination and, therefore, can change notably between different TRM solutions. It is also observed that lime-based TRMs cannot reach their full mechanical properties under indoor conditions even after 3 years. Outdoor conditions lead to better curing of the samples and achieving significantly higher mechanical properties in these composites. However, it can also lead to a significant deterioration at later ages.
... Hence, conventional design practice emphasizes that masonry structures are subject to compressive stresses alone [1]. The bond strength between brick and mortar is also an important parameter, which plays a major role to resist lateral or eccentric load countered by masonry structure [2]. Therefore, it is necessary to have a perfect bond between the masonry unit and the mortar to resist the stress due to loading. ...
Masonry is a heterogeneous material with the most complex, non-linear, anisotropic behaviour among all other construction materials (steel, concrete, etc.). Both masonry compressive strength and bond strength are two important parameters for structural design. A wide range of experimental studies considering two types of fly ash bricks and three grades of cement mortar is conducted to check the influence of masonry bond strength on its compressive strength. During the compressive strength test on stack bonded prisms, it is seen that when the brick–mortar bond strength is poor, the prism failure is also accompanied by a failure of the brick–mortar bond. The experimental result in the present study also reveals that with the increase in shear bond strength compressive strength increases indicating the existence of a correlation between these two important parameters. The correlation between compressive strength and shear bond strength of masonry is investigated and an analytical model is suggested accordingly.
... The failure mechanisms of brick masonry prism are based on the various proportions of brick and mortar samples [39,40]. The mechanisms of masonry prism were observed in experimentally and analytical point of view to identify the compressive strength, stress-strain behavior, young's modulus of masonry along with its components [40][41][42][43][44]. There are much research is carried out to analyze masonry failures with different blended masonry mortar, different types of bricks, bonding type, etc. ...
The study aims to understand the strength improvement and microstructural behavior of ultra-fine fly ash particles through synthesis and characterization techniques by analyzing the fly ash mortar and masonry prism. The process of grinding alters the particle size and specific surface area but not shown any variation in chemical composition are concluded from the microstructural analysis. The multiphase crystalline structures were found through the X-Ray Diffraction. From XRD, a pattern was incorporated to measure the micro-cracks size decrease and the strain was not obtained for a lattice. The reading shows the good amplification in the use of ultra-fine fly ash blended cement mortar associated with raw fly ash. The ultra-fine fly ash masonry block shows higher compressive strength, higher resistance to shear, higher bonding between two bricks compare to conventional masonry blocks. Overall, investigations show that additional use of 45% ultra-fine fly ash in construction applications without compromising the quality.
... Pavía and Henley (2010) concluded that the mortar strength depends on various factors including the block geometry, the mortar type, and the curing time of the specimen. Barr et al. (2015) conducted tests immediately after, 1 minute after, and 15 minutes after construction of the specimens, and concluded that the strength of the mortar is a function of the water absorbed by the block. Thus, although the average value obtained herein is only about 40% of the average value obtained from the results of the tests conducted by other researchers; the value can still be considered satisfactory. ...
Masonry is a construction system that has been used since the beginning of civilization and is still used throughout the world. The finite element method is a recent development that allows complex problems, including structural masonry problems, to be solved. A vast amount of literature exists on finite element modeling, using software such as ABAQUS, to represent experimental masonry models. Based on this established pattern, an experimental and analytical research program was designed and implemented. Thus, a set of tests was conducted to determine the compressive and tensile strengths of the masonry components, i.e., block, mortar, and grout. Bond wrench tests, diagonal tension tests, and horizontal joint shear tests were conducted to characterize the interface between the blocks and the mortar. A finite element model was then developed to represent the physical models and the general conclusion is that the finite element model was able to represent reasonably well the physical models.
... The present study aims to evaluate the most appropriate probability distribution model for the bond strength of fly-ash brick masonry, as the resistance of masonry structures is typically governed by their bond strength. Unreinforced masonry structures resist inplane and out-of-plane lateral forces by the bond strength between brick and mortar (Barr et al. 2015;Teja 2015). Bond strength (shear, flexure tensile, and split tensile) is the most critical parameter that governs the resistance capacity of both load-bearing and infilled masonry structures. ...
Lateral loads such as wind and inertial forces from earthquakes are resisted by the bond strength of brick masonry structures. The consideration of uncertainty in both load and resistance capacity is vital for limit state design of masonry structures. This paper investigates the variability associated with shear, flexure tensile, and split tensile bond strength of fly-ash brick masonry. The bond strength data were obtained from laboratory-prepared specimens made of commercially available fly-ash bricks. Three goodness-of-fit tests, namely Kolmogorov-Smirnov, Kolmogorov-Smirnov-Lilliefors, and Anderson-Darling, were carried out on the selected distributions, and the most appropriate distributions for modeling the considered bond strength parameters are recommended.
... Shell lime with hydratable components has high strength and good weathering resistance, and is suitable for use in highhumidity areas [43,46]. The use of shell lime with hydratable components in ancient building repair can achieve a better restoration effect [47]. ...
... The prewetting time affected the weakly water-powered lime cover (NHL 2) more than the respectably (NHL 3.5) and famously water-powered (NHL 5) lime fasteners. This helped in understanding lime-mortared brickwork and its implementation in the future [16]. In short, a prism was tested in an axial downward tap using two units of brick stone and fly ash bricks using fly ash cement mortar. ...
This research intends to explore the sustainable masonry bond formation and interface behaviour of brick masonry bonds with different cement mortar ratios. To test the sustainable behaviour of different brick bonds, different tests were applied to evaluate the performance of the developed five brick masonry structures with the help of four mortar ratios. Following that pattern, the methodologies of a prism triplet test, a bond wrench test, a shear bond test and strength tests for brick masonry were applied. The prism triplet test explained the bonding behaviour of mortar by producing a maximum strength (0.21 MPa) with a 1:3 mix ratio, and the minimum strength (0.095 MPa) with a 1:8 mix ratio. The bond wrench test showed a bond strength of maximum 0.0685 MPa with a mortar ratio of 1:3 and a minimum of 0.035 MPa with a mortar ratio of 1:8. The strength tests for masonry structures expressed that compressive strength (0.786 MPa) and flexural strength (0.352 MPa) were found to be at maximum level with a mortar ratio (1:3) with an English bond formation. For predictions of compressive and flexural strength, artificial neural networks (ANNs) were deployed, and successful predictions of these values along with the relationships between different properties of the material, mortar combinations and bond combinations are presented to complete the exploration of the relationship. This pattern can be helpful for the selection of sustainable brick masonry formations for housing development.
... In addition, NHL is more compatible with old materials than Portland cement because it has high air permeability as well as adequate strength and stiffness. Since it combines hydraulicity and air hardening, a target strength and durability can be guaranteed, with less sensitivity than air lime to environmental factors [26]. Compared to air lime mortar, NHL mortar shows superior mechanical properties, regardless of the type or content of the aggregates [27]. ...
In addition to non-hydraulic lime, natural hydraulic lime (NHL) is a material widely used to repair and restore historic buildings. In Korea, although lime mortars have been used as important building materials for thousands of years, the sharing of information and technology with other countries has been relatively inactive. While not recognizing the suitability of NHL as a repair material, undesirable materials such as Portland cement have often been selected due to their high strength, ease of use, and hydraulicity, but unfortunately, this has resulted in the irreversible damage of existing elements, especially in historic masonry structures. This study aims to emphasize the need for hydraulic lime for the sustainable preservation of Korea’s architectural heritage. To justify its use, historical and scientific investigations were conducted. By reviewing literature written in the 15th century, it was found that dark limestone was used to manufacture building lime. Based on this, the chemical compositions of different-colored limestone were experimentally analyzed, and significant evidence was found that dicalcium silicate was formed in the quicklime manufactured by calcining blue-green and green-black limestone. Prior to the 19th century, it would have been impossible to record the chemical compositions of various types of limestone, except for visual observations such as color differences. Fortunately, this important information was recorded in royal documents and has been handed down to the present day. Thus, knowledge from 500 years ago could be scientifically interpreted using the latest technology. The link between the historical record and the experimental results shown in this study can contribute to the selection of a suitable material. This is a method for the preventive preservation of historic masonry structures, as it can significantly lower the possibility of future damages caused by efflorescence and freeze–thaw.
... TRMs are composed of continuous fabrics (unidirectional or bidirectional fabrics made of glass, steel, basalt, etc.) embedded in an inorganic matrix (lime-based or cement-based mortars). Due to better compatibility, lime-based mortars are the preferred choice for application to weak masonry and historical structures [7][8][9][10] and are the main subject of this study. ...
Lime-based textile-reinforced mortars (TRM) have recently found a growing interest for repair and strengthening of masonry and historical structures. Despite extensive experimental and numerical investigations performed in the last years on the performance of these composites, there is still a lack of fundamental understanding of the fabric-to-mortar bond behaviour (as one of the main mechanisms affecting the cracking and nonlinear response of these composites) and the parameters affecting that. This paper, aimed at addressing this gap, presents a comprehensive experimental and analytical investigation on how the test setup, embedded length, load rate, mortar age and fabric configuration affect the bond behaviour in lime-based TRMs. In total 160 pull-out tests are performed on a glass-based and a steel-based TRM commonly used for strengthening of masonry structures. The results contribute to standardization of the test procedures for characterization of the fabric-to-mortar bond behaviour, to fundamental understanding of this mechanism and to optimization of the design of these composites for enhancing their mechanical response.
... Glass, steel and basalt are among the most common fiber types used, while for the matrix, cementitious or lime-based mortars are usually used. Lime-based mortars are preferred for application to masonry and historical structures due to compatibility, sustainability issues, breathability and capability of accommodating structural movements [1][2][3]. The effectiveness of this strengthening technique is strongly dependent on the nonlinear properties of the TRM composite and on the mortar-to-substrate bond properties. ...
Non-traditional retrofitting and strengthening, such as textile-reinforced mortar systems (TRMs), have recently received extensive attention for seismic protection of masonry and historical structures. One of the most important parameters in TRM-strengthened masonry is the bond behaviour of textile-to mortar and mortar-to-substrate. Although in the literature there are some researches about the bond behaviour between TRM and substrate, few attention has been paid to the bond of textile-to-mortar under pull-out test.
An analytical model simulating the bond behaviour of textile-to-mortar composites is presented to relate the mechanical properties of the mortar and the textile as well as the load-slip curve gained from the pull-out tests. The objective of this study is to obtain the bond-slip law of different textile configurations and embedded lengths. In the formulation of the pull-out model, a modified approach based on a mathematical model by Banholzer is applied. Firstly, based on the experimental results and material properties, a relationship between the bond shear stress and the relative slip along the fiber-mortar interface is obtained.
... While for the matrix, cementitious or lime-based mortars are usually used. Lime-based mortars are preferred for application to masonry and historical structures due to compatibility, sustainability issues, breathability and capability of accommodating structural movements [4][5][6]. ...
Textile-reinforced mortar (TRM) composites have received extensive attention as a sustainable solution for seismic strengthening of masonry and historical structures. This new system is composed of textile fibers embedded in an inorganic matrix and is applied on the masonry substrate surface as an externally bonded reinforcement (EBR) system. The bond at the textile-to-mortar and at the mortar-to-substrate interfaces are the main stress-transfer mechanisms and therefore should be thoroughly investigated.
Although several studies have been focused on characterization of the bond behavior in TRM-masonry composites during the last years, there is still a lack of suitable constitutive laws. Most of the available studies have addressed the bond behavior through single-lap shear bond tests in which the bond of the TRM system to masonry substrate is evaluated. The bond performance between the fiber and mortar, however, has received few attention and is the main subject of this study.
The presented work consist of fiber pull-out tests on a (unidirectional) steel-based and a (bidirectional) glass-based TRM composite as common reinforcing systems. The roles of transverse fibers (in glass-based TRM) as well as number of fibers on the bond behavior are also investigated. The results show that transverse elements cause toughness to increase. In addition, by increasing the number of fibers, the obtained failure modes change from slipping to mortar cracking.
... Therefore, the existing knowledge must be fully assessed, validated, optimized and complemented by means of the current state-of-the-art for calculating, testing and modeling. The authors acknowledge that this literature review is the first step of a more complex process that involves in-depth scientific research through multi-disciplinary collaborations, possibly by building upon current research topics which includes determination of reliable material properties (Barr et al., 2015;Rai and Dhanapal, 2015), experimental testing (Milosevic et al., 2012;Ahmad et al., 2013), numerical modeling (Parajuli, 2009;Tarque et al., 2014), and ultimately code revision (UNDP/ERRRP-project: NEP/07/010, 2009; Magenes and Penna, 2011), to name a few. ...
A literature review was carried out with the aim to determine the current state-of-the-art with regards to non-engineered stone masonry in seismic areas. Specific search criteria and definitions were determined for school buildings with loadbearing walls of rubble stone masonry in cement mortar, nominally tied with horizontal reinforcements. A total of 47 relevant field manuals between 1972 and 2017 were analyzed for eligibility and checked for compatibility, initially with 109 national building codes. An overview was created of similarities, contradictions, gaps and differences between the publications. As the majority of the practical manuals target the Himalayan context, the most relevant codes for the comparison were the Indian and Nepali seismic and building codes. Only 9 manuals describe design and construction processes for schools, even though this conflicts with the codes which specifically prohibit the use of stone masonry for buildings with importance factor 1.5 or higher. It was noticed that 7 out of 9 manuals are (co-)written by the same author, and that the available knowledge, which is largely based on empirical evidence, can be traced back to just a few main sources. However, no consistency nor consensus was found on almost all key topics, such as main dimensions, openings and reinforcing elements. Also, the same illustrations and tables are copied over and over again, including apparent conflicts between the details. The fact that this has never been rectified, as well as the fact that the Indian and Nepali seismic codes have not been properly updated since 1994, are indications that the knowledge has not evolved much since the 1980's. It is concluded that the available information contains many contradictions and has become ambiguous. This raises questions about the correctness, reliability and actual value of the knowledge. The paper suggest that the existing knowledge must be fully assessed, validated, optimized and complemented by means of the current state-of-the-art for calculating, testing and modeling. To address this, the authors have started an initiative named SMARTnet, and make an appeal to experts and academics worldwide, to exchange their knowledge and to support the project with their time and expertise.
... While for the matrix, cementitious or lime-based mortars are usually used. Lime-based mortars are preferred for application to masonry and historical structures due to compatibility, sustainability issues, breathability and capability of accommodating structural movements [6][7][8][9]. ...
The use of Textile Reinforced Mortar (TRM) composites for Externally Bonded Reinforcement (EBR) of reinforced concrete (RC) and masonry structures has attracted several attentions during the last years. The effectiveness of these composites in structural reinforcement is significantly dependent on the TRM-to-substrate and the fiber-to-mortar bond behavior. Despite the importance of the latter, that controls the crack distribution on these composites, have received few attentions and is relatively unknown.
This paper presents a combined experimental and analytical study on the effect of fiber-embedded length and configuration on the pull-out response. From the obtained results, bond-slip laws are proposed for TRM composites made of unidirectional and bidirectional grids. The tests are performed on a (unidirectional) steel-based and a (bidirectional) glass-based TRM composite as common reinforcing systems. A comparison is also made between the results obtained from single-fiber pull-out tests and conventional single-lap shear bond tests to highlight the differences/similarities between these two test methods.
... Barr ve arkadaşları [18] yaptıkları çalışmada, doğal hidrolik kireç ve doğal çimento harçlı yığma yapıların bağ dayanımları üzerine araştırmada bulunmuşlardır. Bu amaçla 3 farklı dayanıma sahip hidrolik kireç ile çimento harçlı bağlayıcılar kullanılarak yapılan yığma blokların eğilme bağ dayanımları bağ burkulma testleri ile ölçmüşlerdir. ...
Tarihi eserlerin restorasyonu ve rekonstrüksiyonunda aslına uygun malzemelere yakın malzemelerin kullanılması büyük önem arz etmektedir. Ahşap, kerpiç, tuğla, taş ve harç gibi malzemeler tarihi yapıların onarımında kullanılan malzemelerdir. Horasan harcı bu amaçla kullanılan en önemli malzemelerden birisidir. Horasan Harcı öğütülmüş kiremit ve hidrolik kireç karışımından oluşmaktadır. Beton ve harç karışımlarına benzer şekilde büzülme çatlaklarının oluşması, hidrolik kireçli karışımlarda da dayanım ve dayanıklılık problemlerine neden olmaktadır. Bu çalışmada, polipropilen lif kullanımının hidrolik kireçli harçların basınç ve eğilme dayanımına, su emme kapasitesine ve kuruma büzülme davranışına etkisi incelenmiştir. Bu bağlamda bağlayıcı olarak doğal hidrolik kireç, agrega olarak kırma taş kireç agregası içeren lifli ve lifsiz olmak üzere 3 farklı seri harç karışımları hazırlanmıştır. Dayanım özellikleri ve kuruma büzülme davranışlarını iyileştirmek amacı ile harç karışımlarına toplam hacmin %0,5 ve %1,0’i oranlarında polipropilen lif ilave edilmiştir. Tüm karışımlarda su/bağlayıcı, kum/bağlayıcı ve yayılma değerleri sırasıyla 0,6, 2,75 ve 150±10 mm olarak sabit tutulmuştur. Bilindiği gibi lif kullanımı ile harç karışımlarının işlenebilirliği olumsuz etkilenmektedir. Bu sebeple lifli karışımlarda 150±10 mm yayılma değerini sağlamak için lif içermeyen karışıma kıyasla daha fazla su eklenmesi gerekmektedir. Ancak dayanım azalmasını engellemek amacıyla lifli ve lif içermeyen karışımlarda su miktarları sabit tutulmuştur. 150±10 mm hedef yayılma değerini sağlamak için ilaveten değişik oranlarda polikarboksilat esaslı su azaltıcı katkı kullanılmıştır. Üretilen harç karışımların 1, 3, 7 ve 28 günlük basınç ve eğilme dayanımları, 28 günlük su emme ve kuruma-büzülme değerleri belirlenmiştir. Sonuçlara göre lif kullanımı ile istenilen yayılma değerini sağlamak için su azaltıcı katkı gereksinimi artmıştır. Dayanım, su emme ve büzülme değerlerinde ciddi mertebelerde iyileşme olmamıştır.
The need to develop products for the conservation of the architectural heritage, in particular binders for plasters, is increased nowadays and those products are required to be in line with green production system and materials in full compliance with current environmental sustainability criteria. It has already been established that Natural Hydraulic Lime (NHL) is a good material for restoration; it is compatible with ancient materials and respects the environmental requirements. The use of green technologies often involves the partial use of environmental low impact materials that do not always find practical use in restoration. The starting point of the research is the selection and study of NHL-based commercial plasters used for the conservation of historic masonries and their optimization through additives cement-free in order to create green products for applications in the conservative restoration of historical heritage. The five different types of formulations chosen for this work, has been evaluated and analyzed from a physical and mechanical point of view, through dynamic elastic module, compression and flexion tests, porosity and density analysis. During the execution of the research, the focus was on the effect of microstructural features of porous material, investigated in laboratory with porosimetry test as they are fundamental parameters for studying compatibility with pre-existing materials and durability over time.KeywordsCommercial NHL plasterconservation mortarsporosityphysical-mechanical parameterscompatibility
Historically, building stone was extracted and shaped by hand. To produce a flat surface using a mallet and chisel requires the time and energy of a skilled mason. As such, the highest level of workmanship was generally reserved only for the seen faces of stones. The joint surfaces were given less attention and would subsequently be “rougher”.In the modern era, diamond tipped gantry or wire saws are the standard equipment for stone processing. For the purposes of building conservation, the seen face of replacement stones are usually hand chiselled in keeping with the original design. However, it has become increasingly common for the joints of the new stones to be left as a clean diamond sawn surface.This paper examines if and how the difference in surface area between various stone surface finishes changes the characteristics of the lime mortar joint. The paper includes a surface area comparison of modern and historic stone surface finishes. This is followed by practical testing to ascertain how lime mortar joint/adhesive bond strength changes in relation to the amount of stone surface area available for adhesion.The results of the testing suggest a direct relationship between stone surface finish, joint surface area and lime mortar adhesion.KeywordsStone ConservationLime Mortar AdhesionStone Surface AreaBond WrenchStone Joint DesignStone Surface Roughness
This paper studied the swelling behavior of two types of superabsorbent polymer (SAP) and their effect on the properties of natural hydraulic lime (NHL2). The rheology of NHL2 paste depends on the water absorption kinetics of SAP. Although chemically different, SAPs can promote hydration and Carbonation of NHL2. Moreover, SAPs can compensate for autogenous shrinkage. The hydration products of NHL showed a gradient growth on the SAP surface and formed an NHL/SAP interface transition zone. However, SAP will leave pores that provide access for CO2 to enter the matrix. As a result, the porosity increased, reducing the compressive strength.
4 Reliable design and application of textile-reinforced mortar (TRM) composites for the repair of 5 existing masonry and concrete structures requires a fundamental understanding of the textile-to-6 mortar bond behavior as one of the main mechanisms controlling their nonlinear response and 7 cracking behavior. Suitable test setups and analytical models are needed to extract the bond-slip 8 laws from the experimental pull-out tests. This paper proposes a new bond-slip law and analytical 9 model, which predicts the bond behavior of lime and cement-based TRM composites considering 10 the slip hardening and softening effects observed in experimental tests. For this purpose, the pull-11 out response of experimental specimens with different fiber types (steel and glass), bond lengths, 12 and mortar age are analyzed, and their bond slip-laws are extracted. The accuracy of the developed 13 model is shown by comparing analytical and experimental results. 14
Multilayer mortar systems have been diachronically used in historic structures. Renders and plasters were usually based on lime and presented specific characteristics (i.e. stratigraphy), while their durability was mostly attributed to the adhesion and overall performance of the mortar layers. During restoration works, the replacement or repair of successive mortar layers (i.e. renders, plasters, mural paintings’ substrates) is a common practice, whose effectiveness is closely related to the proper materials and techniques applied. In this paper, an effort was made to enhance the properties of a double-layered mortar system, based on lime and natural pozzolan. To this direction, pre-wetting of the internal layer was performed, using various organic and inorganic water-solutions (lime wash, primal, hydroground) that were further nano-modified (1.5% w/w, nano-silica). A series of specimens were manufactured and their physico-mechanical properties were tested at the age of 28 and 90 days (porosity, apparent specific gravity, water absorption coefficient, vapor permeability, dynamic modulus of elasticity, flexural and compressive strength). Additionally, bond strength by pull off and tensile bond strength were performed. From the evaluation of the results, it was concluded that the application of the proposed nano-modified solutions improved significantly the adhesion of the mortar layers. The results were encouraging, indicating that a limited, low cost and non invasive technique, could enhance their performance, during restoration works.
Although thin layer mortared (TLM) masonry has potential economic benefits over conventional masonry construction, the lack of understanding on material and structural characteristics under various loading situations hamper its widespread usage. Hitherto few systematic research studies were reported on this masonry system. Therefore in order to better understand the material characteristics, an experimental programme was carried out to characterise the TLM clay masonry and its constituents. Tensile bond, shear bond, flexural and compression strengths and deformation characteristics of TLM clay masonry were investigated in this research using clay bricks with proprietary and laboratory made mortars. The results have revealed that the TLM masonry exhibit failure modes different to the conventional masonry: however, where the bond strength commensurate to the conventional mortar, the distinction between the TLM and conventional masonries vanishes. Therefore it is recommended to select appropriate TLM type suitable for the design requirements. Additionally the research generated data of key material properties that might be useful for nonlinear numerical analysis of TLM masonry.
In recent years, natural hydraulic lime (NHL) mortars have gained increased attention from researchers, not only as restoration materials for monuments and historical buildings, but also as an eco-friendly material which can be used as binder to formulate mortars for contemporary structures. In the present study, an extended database related to NHL mortars is compiled, related to all three NHL grades (NHL5, NHL3.5, NHL2) and soft computing techniques namely artificial neural networks (ANN) are utilized to reveal the influence of the mortar’s mix design on mechanical strength, as well as to predict the compressive strength of NHL mortar mixes. Influence of the binder to aggregate, water to binder and maximum aggregate size on the compressive strength of a mortar at different mortar ages is revealed, for the three grades of natural hydraulic lime, further highlighting aspects of this “new” material, which has been used as a binder since antiquity.
The shear, flexural and axial tensile bond strengths of alkali-activated slag concrete hollow block (AASCHB) masonry layered with alkali-activated slag (AAS) mortar were investigated in this study. A comprehensive experimental investigation was conducted to assess the effect of the AAS mortar strength on the bond characteristics of the masonry. The bond strength of the AASCHB masonry was found to be directly related to the compressive strength of the AAS mortar, where higher compressive strength led to higher bond strength. In addition, new expressions for the bond strength were developed for AASCHB masonry based on the compressive strength of AAS mortar.
Masonry walls represent one of the most common applied constructions in civil engineering and architecture. The inhomogeneous nature of masonry imposes a challenge in the development of robust modeling techniques especially under high dynamic loads. In this contribution some modeling strategies are discussed which are suitable for the simulation of unreinforced masonry walls under explosion loads. The damage formation of the wall under loads resulting from far-field as well as contact explosions is investigated. Firstly the issue of an appropriate material model for bricks under high strain rates is discussed. Through a proper adaptation of a material model initially developed for concrete under blast loads all the necessary parameters for the bricks are derived. Subsequently the focus lies in capturing the local damage formation and the resulting debris due to a contact detonation. Small parts of the wall in the proximity of the explosion separate from the main body of the wall and travel at high velocities. They can establish an additional danger for persons and infrastructure which theoretically lie in a secure distance from the target of the explosion. The numerical results which will be presented in this paper are validated with appropriate experiments.
Ultrasonic-percussive drills are a leading technology for small rock drilling applications where power and weight-on-bit are at a premium. The concept uses ultrasonic vibrations to excite an oscillatory motion in a free-mass, which then delivers impulsive blows to a drilling-bit. This is a relatively complex dynamic problem involving the transducer, the free-mass, the drilling-bit and, to a certain extent, the rock surface itself. This paper examines the performance of a full-wavelength transducer compared to a half-wavelength system, which may be more attractive due to mass and dimensional drivers. To compare the two approaches, three-dimensional finite element models of the ultrasonic-percussive stacks using full and half wavelength ultrasonic transducers are created to assess delivered impulse at similar power settings. In addition, impact-induced stress levels are evaluated to optimize the design of drill tools at a range of internal spring rates before, finally, experimental drilling is conducted. The results suggest that full-wavelength systems will yield much more effective impulse but, interestingly, their actual drilling performance was only marginally better than half-wavelength equivalents.
The aim of the present work is to study the effect of particle size reduction by applying top-down
nanotechnology such as ball mill grinding process with the addition of amine-based grinding aids. The
particle size reduction in synthesis process and its characterization were investigated for fly ash
particles. The Rosin-Rammler-Bennet (RRB) distribution model using mathematical formulations
were studied for fly ash ground particles. The hardened properties of grinding aid fly ash composite
mortar were studied using compressive strength test. The optimum grinding time was 120 min
identified through the particle size distribution analysis. The mean particle size decreased from
92.09 μmto 10.5 μmin which there is 89% reduction in particle size due to the grinding of fly ash
particle with grinding aids. The compressive strength results show that substitutions of Ordinary
Portland Cement (OPC) mortar by Amine-based Grinding aid Fly Ash (AGFA) 15% gives 12, 23% and
at 30% gives 6,8%of higher strength compare to the substitutions of raw fly ash. The addition of
grinding aids in grinding process gives more advantages to reduce the particle size without changing
chemical composition. The AGFA sample shows better performance in compressive strength and
bond strength behavior of masonry prism. It may suggest that amine based grinding aids play a vital
role and feasible to use in fly ash grinding process.
Tarihi eserlerin restorasyonu ve rekonstrüksiyonunda aslına uygun malzemelere yakın malzemelerin kullanılması büyük önem arz etmektedir. Ahşap, kerpiç, tuğla, taş ve harç gibi malzemeler tarihi yapıların onarımında kullanılan malzemelerdir. Horasan harcı bu amaçla kullanılan en önemli malzemelerden birisidir. Horasan Harcı öğütülmüş kiremit ve hidrolik kireç karışımından oluşmaktadır. Beton ve harç karışımlarına benzer şekilde büzülme çatlaklarının oluşması, hidrolik kireçli karışımlarda da dayanım ve dayanıklılık problemlerine neden olmaktadır. Bu çalışmada, polipropilen lif kullanımının hidrolik kireçli harçların basınç ve eğilme dayanımına, su emme kapasitesine ve kuruma büzülme davranışına etkisi incelenmiştir. Bu bağlamda bağlayıcı olarak doğal hidrolik kireç, agrega olarak kırma taş kireç agregası içeren lifli ve lifsiz olmak üzere 3 farklı seri harç karışımları hazırlanmıştır. Dayanım özellikleri ve kuruma büzülme davranışlarını iyileştirmek amacı ile harç karışımlarına toplam hacmin %0,5 ve %1,0’i oranlarında polipropilen lif ilave edilmiştir. Tüm karışımlarda su/bağlayıcı, kum/bağlayıcı ve yayılma değerleri sırasıyla 0,6, 2,75 ve 150±10 mm olarak sabit tutulmuştur. Bilindiği gibi lif kullanımı ile harç karışımlarının işlenebilirliği olumsuz etkilenmektedir. Bu sebeple lifli karışımlarda 150±10 mm yayılma değerini sağlamak için lif içermeyen karışıma kıyasla daha fazla su eklenmesi gerekmektedir. Ancak dayanım azalmasını engellemek amacıyla lifli ve lif içermeyen karışımlarda su miktarları sabit tutulmuştur. 150±10 mm hedef yayılma değerini sağlamak için ilaveten değişik oranlarda polikarboksilat esaslı su azaltıcı katkı kullanılmıştır. Üretilen harç karışımların 1, 3, 7 ve 28 günlük basınç ve eğilme dayanımları, 28 günlük su emme ve kuruma-büzülme değerleri belirlenmiştir. Sonuçlara göre lif kullanımı ile istenilen yayılma değerini sağlamak için su azaltıcı katkı gereksinimi artmıştır. Dayanım, su emme ve büzülme değerlerinde ciddi mertebelerde iyileşme olmamıştır.
This paper presents a set of mechanical characteristics for a pozzolanic mortar consisting of hydrated lime and metakaolin, which is used as filler between metallic connectors and marble blocks during restoration activities of ancient monuments in Greece. Mechanical properties include the uniaxial and triaxial compressive strength, the indirect tensile strength, the bending strength, the elastic modulus and Poisson’s ratio and a shear failure criterion. Cored cylindrical specimens are used for determining the uniaxial and triaxial compressive behavior and the indirect tensile strength of the mortar, thus ensuring the repeatability of the experimental results. The triaxial tests indicated a plastic behavior of the mortars under study, enabling them to perform well in conditions of high shear forces. Calcite and hydraulic components formed in the setting procedure contributed to the plasticity of the final mortar. The mechanical properties that were developed can be utilized to model material behavior and failure under conditions of confined or triaxial loading. The development of a shear failure criterion for a pozzolanic mortar is a substantial accomplishment that has not been previously reported in the international literature.
This paper aims at improving the quality of lime mortar masonry by understanding the mechanics of mortars and masonry and their interaction. It investigates how the mortar's compressive and flexural strengths impact the compressive and bond strength of clay brick masonry bound with calcium lime (CL) and natural hydraulic lime (NHL) mortars. It concludes that the strength of the bond has a greater impact on the compressive strength of masonry than the mortar's strength. The masonry compressive strength increased proportionally to the strength of the bond up to 6 months. A regression analysis, giving a second order equation with coefficient of determination (R 2) of 0.918, demonstrates a strong and predictable relationship between bond strength and masonry compressive strength. It was noted that CL90s mortar masonry reaching a high bond value was stronger than that built with a stronger mortar but displaying a poorer bond. Finally, the mechanics of lime mortars and their masonry are similar. The predominantly elastic behaviour of the mortars of higher hydraulic strength compares well with the elastic and brittle behaviour of their masonry, with either little (NHL2) or non-existent plasticity (NHL3.5 and 5); in contrast, the CL90 mortar and masonry exhibit a plastic behaviour.
This paper measures the bond strength of natural hydraulic-lime (NHL) mortars, to further characterise their properties and
enhance their use in building. An additional objective is to correlate bond strength with mortar hydraulicity, water content,
workability and water retention, to develop mortars of high bond strength that would improve the quality of masonry. To this
aim, the flexural bond strength of masonry, built with mortars of three hydraulic strengths-each including the water amount
required to attain three specific flows (165, 185 and 195mm), was measured with the bond wrench test. The results suggest
that NHL mortars possess high water retention, and this enables a strong bond that compares well to that of Portland cement
and cement/lime mortars. The results also indicate that bond strength is not determined by the binder’s hydraulic strength,
but it increases proportionally to the mortar’s water retention. The paper concludes that for the NHL5 mortars, the 185mm
flow results in the strongest bond, simultaneously providing the highest water retention and best workability. However, for
the lower strengths (NHL 2 and NHL 3.5 mortars), the water content required to attain the flows that provide an optimum workability
(165 and 165–185mm, respectively) does not lead to the strongest bond, but it is the highest flow values that provide the
NHL2 and NHL3.5 mortars with the strongest bond and, in most instances, the highest water retention.
KeywordsFlexural bond strength-Natural hydraulic-lime mortar-Bond wrench test-Workability-Water retention-Initial flow
Description
Presents 28 papers that address: recent developments in materials, components, and performance of assemblages • up to date material on new test method development and review and design philosophy • performance of conventional and new materials under ASTM specifications • substantiation and/or deficiencies of existing ASTM test methods • problem areas in masonry and proposed solutions • and structural design and analysis methodologies.
This article deals with the phenomenon of the early water transport between fresh mortar and a dry brick. Two bricks with different transport parameters were considered in combination with two different mortars: a lime hydrate mortar and a cement mortar. Water transport was monitored during the first hour after contact using X-ray imaging and simulated using a commercial control volume (CVM) software tool. Such simulations are made possible by a newly developed method to measure transport parameters of fresh mortars. The amount of water leaving the mortar in 1 h depends mostly on two parameters of the mortar: initial and residual water content. The rate of flow across the interface shows a complex behaviour and is larger for cement mortar and for strongly absorbing brick. The accuracy of simulations is somewhat limited by the importance of over-capillary effects in the bricks near the interface. It appears that this over-capillary water is partly distributed over the brick, and partly reabsorbed by the mortar.
This paper builds on previous work investigating the flexural bond strength, initial shear strength and compressive strength of fired clay brickwork built using hydraulic lime mortars. It has been shown that whilst flexural bond strength and initial shear strength of the brickwork generally increased with mortar strength, flexural strength was significantly impaired by both low and high brick water absorption. This paper describes a study of the pore size distribution of the surfaces of brick and mortar at the brick/mortar interface using Mercury Intrusion Porosimetry. The paper identifies critical pore sizes at the brick surface which would appear to govern resultant bond strength.
Natural hydraulic limes are used as an alternative to cement-based binders in mortars and renders for the repair and maintenance of historic structures as well as in new building. This paper discusses the role of the binder type, the grain size and the packing density of aggregates on the physico-chemical and mechanical characteristics of hydraulic lime mortars. Empirical formulae connecting the compressive strength with: (a) dynamic modulus of elasticity and (b) mean pore radius, have been extracted and discussed. Overall, the results have indicated that the microstructure of the binder and the packing density aggregates are the parameters that dominate the performance of the hydraulic mortars and therefore should be seriously considered during field applications.
The increasing use of lime-based mortars for the restoration of historic buildings and structures justifies the research on these materials. The focus of this paper is the effect of technological variables on pore structure and mechanical properties of lime-based mortars. The influence of curing time, binder–aggregate (B/Ag) ratio, aggregate attributes and porosity is discussed. Mortars prepared with aerial lime, varying aggregate types and B/Ag ratios ranging from 1:1 to 1:5 by volume were tested. Compressive and flexural strength measurements, as well as X-ray diffraction (XRD) and thermal studies, were performed after 3, 7, 28, 91, 182 and 365 days. A strong increase in strength of mortar mixtures after 365 curing days (as compared to 28 curing days) is found. In spite of the fact that larger amounts of binder increase the total porosity, the strength of these mixtures is also increased. A good interlocked structure is obtained as binder contents increase. Also, higher porosities allow better portlandite carbonation. A relationship between mechanical properties and pore structure was established. However, in case of binder excess, the increase in voids leads to a strength reduction. The use of calcareous aggregates improves strength more as compared to the use of siliceous aggregates. Factors as grain size distribution and grain shape of the aggregates have also been considered.
This paper presents experimental results from an ongoing study investigating the flexural bond strength, initial shear strength and compressive strength of brickwork built using natural hydraulic lime mortars. All tests were conducted in accordance with relevant standard procedures. Flexural bond strengths, with planes of failure parallel and perpendicular to bed joints, were determined by panel (wallette) tests. Bond wrench testing of stack-bonded prisms was also conducted to investigate further the material influences on flexural strength. The main parameters studied in this investigation were mortar mix design (binder : aggregate ratio; lime grade) and brick water absorption characteristics. The flexural bond strength and initial shear strength of the brickwork in general increased with mortar strength, but flexural bond strength was significantly impaired by both low and high brick water absorption. The bond wrench test was found to be a reliable, quick and easy, alternative test procedure to determine flexural strength (with plane of failure) parallel to the bed joints.
Sand constitutes bulk of the mortar volume. Sand grading can influence the characteristics of mortar and masonry. Influence of sand grading on the characteristics of two types of mortars and soil–cement block masonry are examined in this paper. Three different sand gradings were used to examine the workability, strength, water retentivity, drying shrinkage and stress–strain characteristics of cement mortar and cement–lime mortar. Bond strength, compressive strength and stress–strain characteristics of soil–cement block masonry were also examined using these mortars. Major findings of the study are: (a) for a given consistency mortar with fine sand requires 25–30% more water, (b) as the sand becomes fine mortar compressive strength and modulus decreases while drying shrinkage increases, (c) fine sand reduces the tensile bond strength of masonry, whereas masonry compressive strength is not sensitive to sand grading variations and (d) masonry modulus reduces as the sand used in the mortar becomes finer.
Small panels of brick masonry have been used to study the resistance to moisture penetration and the strength of bond of brickwork in relation to several factors. Results of tests are presented to show the influence of properties of bricks and mortars on leakage and bond strength. Information is presented on the effects of several other factors that are governed by the technique used by the bricklayer in constructing masonry. These factors include the consistency of the mortar when used, the time interval between spreading a mortar bed and laying a brick in it, and the extent to which a brick is tapped into the mortar. The effects of tooling of mortar joints and varying the thickness of mortar joints are also considered. Des petits panneaux de maconnerie de brique ont servi à é tudier la résistance à la pénétration de l'humidité et la ré sistance du liant des maconneries selon plusieurs facteurs. Les résultats des essais sont présentés de facon à mettre en évidence l'influence des caractéristiques physiques des briques et des mortiers sur les fuites et la résistance du liant. Ce document donne des renseignements sur les effets d'autres facteurs qui dépendent des techniques employées par le macon au moment de la construction. Ces facteurs sont la consistance du mortier au moment de son utilisation, la duré e séparant l'étalement du mortier et la pose d'un rang de brique, le frappage des briques déposées sur le mortier. Les effets du travail du mortier des joints à l'aide d' outils et les différentes épaisseurs de mortier sont é galement étudiés. RES
Mortars in historic buildings: a review the scientific and conservation literature, Historic Scotland
- Jj Hughes
- J Valek
Hughes JJ, Valek J. Mortars in historic buildings: a review the scientific and
conservation literature, Historic Scotland; 2003, p. 97 (ISBN 1903570824).
Saint Astier natural hydraulic lime-mineralogy & chemistry of raw materials Available at: <http://www.limes.us/technicalinfo/mineralogy-chemistry-of-raw-materials/>
- Usa Transmineral
- Inc
Transmineral USA Inc. 2014. Saint Astier natural hydraulic lime-mineralogy
& chemistry of raw materials. Available at: <http://www.limes.us/technicalinfo/mineralogy-chemistry-of-raw-materials/> [accessed 25.02.15].
Technical specifications – prompt natural cement – the Roman cement of Grenoble
- D Sommain
Sommain D. Technical specifications – prompt natural cement – the Roman cement of Grenoble. Available at <http://www.romanportland.net/files/doc/ cahier_technique_cr_cnp_eng.pdf>; 2007 [accessed 25.02.15].
Methods of test for masonry-Part 5: determination of bond strength by the bond wrench method BSI
- Bs British Standards Institution
- En
British Standards Institution, BS EN 1052-5:2005. Methods of test for masonry-Part 5: determination of bond strength by the bond wrench method BSI,
London.
Building limes in conservation
- I Brocklebank
- Editor
Brocklebank I, editor. Building limes in conservation. Donhead Publishing;
2012. p. 376. ISBN 9781873394953.
Influence of interfacial material pore structure on the strength of the brick/lime mortar bond
- M Lawrence
- P Walker
- Z Zhou
Lawrence M, Walker P, Zhou Z. Influence of interfacial material pore structure
on the strength of the brick/lime mortar bond. Idem, p. 373-381.
Factors affecting bond strength and resistance to moisture penetration of brick masonry. Symposium on Masonry Testing, ASTM Special Technical Publication Noservices/masonry-production/> for sandstone block production details
- T Ritchie
- Ji Davison
Ritchie T, Davison JI. Factors affecting bond strength and resistance to
moisture penetration of brick masonry. Symposium on Masonry Testing,
ASTM Special Technical Publication No. 320, 1962, p. 16-30.
[16] See
<http://www.tradstocks.co.uk/services/masonry-production/>
for
sandstone block production details [accessed 25.02.15].
Technical specifications-prompt natural cement-the Roman cement of Grenoble Available at <http://www.romanportland.net/files/doc/ cahier_technique_cr_cnp_eng.pdf>
- D Sommain
Sommain D. Technical specifications-prompt natural cement-the Roman
cement of Grenoble. Available at <http://www.romanportland.net/files/doc/
cahier_technique_cr_cnp_eng.pdf>; 2007 [accessed 25.02.15].
Methods of test for mortar for masonry-Part 11: determination of flexural and compressive strength of hardened mortar BSI
- Bs British Standards Institution
- En
British Standards Institution, BS EN 1015-11:1999. Methods of test for mortar
for masonry-Part 11: determination of flexural and compressive strength of
hardened mortar BSI, London.
Methods of test for masonry-Part 2: determination of flexural Strength BSI
- Bs British Standards Institution
- En
British Standards Institution, BS EN 1052-2:1999. Methods of test for masonry-Part 2: determination of flexural Strength BSI, London.
BRE Digest 360-Testing bond strength of masonry BRE
Building Research Establishment (BRE), BRE Digest 360-Testing bond
strength of masonry BRE, 1991.
Eurocode 6-Design of masonry structures-Part 2: design considerations, selection of materials and execution of masonry BSI
- Bs British Standards Institution
- En
British Standards Institution, BS EN 1996-2:2006. Eurocode 6-Design of
masonry structures-Part 2: design considerations, selection of materials and
execution of masonry BSI, London.