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Mix proportions of concrete of strength of 50 MPa and 30 MPa (Soutsos et al., 2016) and their equivalent mortars.
Source publication
The concrete mixes used were of 28-day mean strengths of 50 and 30 MPa and also had partial Portland cement (PC) replacement with ground granulated blast-furnace slag (GGBS) and fly ash (FA). These mixes were the ones used in a UK based project which involved casting of blocks, walls and slabs. The strength development of “equivalent” mortar mixes...
Contexts in source publication
Context 1
... ASTM C1074-11 (ASTM, 2011) requirements were for the mortars to have the same water-binder (w/b) ratio as the concrete and the fine aggregate to binder ratio to be equal to the coarse aggregate to binder ratio of the concrete. The resulting mortar mixture proportions are shown in Table 1, alongside the concrete mixes. and BS EN 450-1:2012 (BSI, 2012), respectively. ...
Context 2
... sand to binder ratios need to be equal to the coarse aggregate to binder ratios of the concretes. The mix proportions of the equivalent mortars, shown in Table 1, have been calculated from those of the corresponding concretes which are also shown in Table 1. ...
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Citations
... Temperature sensitivity of cementitious materials is normally quantified through the "apparent" activation energy of a particular mix (Soutsos et al. 2017), an indicator for temperature dependency of concrete properties. However, it is still not clear whether the "apparent" activation energy is property-dependent, or one value can be used to represent the temperature sensitivity of different concrete properties (Kanavaris 2017; Kada-Benameur et al. 2000; Granja et al. 2023. ...
Over the past years there has been an increasing trend to use supplementary cementitious materials in concrete to improve its sustainability credentials and durability properties. Perhaps amongst the most popular supplementary cementitious materials is ground granulated blast-furnace slag (GGBS). While the hydration and setting characteristics of mixes with GGBS cured under standard conditions (20°C) has been adequately investigated, the effect of temperature on heat of hydration and setting and the interrelation of these properties has not been evaluated for GGBS containing mixes. In this study, the heat of hydration and setting behaviour of mixes with various levels of GGBS (0, 20, 35, 50 and 70%) cured under elevated temperatures (20, 30, 40, 50 and 60°C) is determined. Elevated curing temperature accelerates the hydration reactions and can significantly reduce the setting time of GGBS-containing mixes. The investigation of heat of hydration at very early ages, can provide an indication of the initial and final setting times of cementitious mixes. The “apparent” activation energy used to characterise temperature sensitivity of cementitious systems, is calculated based on heat of hydration and setting time measurements. It was found that the “apparent” activation energy increases with GGBS content for both heat of hydration and setting behaviour. The value of “apparent” activation energy differs significantly depending on the material property that is considered, such as compressive strength, heat of hydration or setting time.
... The recommended value of E a for concrete formed from Type I Portland cement, according to ASTM C 1074, is 40-45 kJ/mol [22]. Soutsos et al. [26] determined statistically that E a for pure cemented concrete with different water-binder ratios ranges from 30 to 50 kJ/mol. E a obtained herein for the FA-0 specimens falls in the range 39.61-43.66 ...
... No current recommendation exists for the range of E a for hydraulic concrete with different fly ash contents. However, previous studies [26,27] show that, due to the low activity of fly ash, the use of fly ash to partially replace cement reduces the activation energy of concrete. In the present work, E a decreases with increasing fly ash content for a given temperature, which is consistent with these previous studies. ...
... In Eq. (1), T represents the average concrete temperature during the time interval Δt, E refers to the apparent activation energy of the mixture and R denotes the universal gas constant. It is noteworthy that this equation was also preferred in studies concerning the maturity of pozzolanic concrete mixtures (Soutsos et al. 2017(Soutsos et al. , 2018(Soutsos et al. , 2019. ...
... Guo (1989) claimed a value between 30-40 kJ/mol. Furthermore, in the literature higher values of apparent activation energies were reported in the presence of slag while lower values were reported in the presence of fly ash (Soutsos et al. 2017(Soutsos et al. , 2018Kanavaris et al. 2023). In addition, alongside the recommended values of activation energy, the ASTM C 1074 also describes an experimental methodology for calculating the apparent activation energy of a particular mixture. ...
... The researchers who investigated the hydration kinetics of fly ash and/or ground granulated blast furnace slagcontaining mixtures under various temperatures and applied the maturity method revealed that the temperature sensitivities of such mixtures were different from that of ordinary Portland cement. (Kanavaris et al. 2023;Poole et al. 2007;Riding et al. 2012;Sargam et al. 2012;Siddiqui and Riding 2012;Soutsos et al. 2017Soutsos et al. , 2018Soutsos et al. , 2019. ...
This study examines the application of the maturity method to obtain the ultimate properties of ECC. Within the scope of the study, the maturity method according to the Arrhenius equation was applied to four different ECC mixtures encountered in the literature: the activation energies and the ages at which they achieve ultimate properties were determined. Subsequently, the mixtures were subjected to standard and accelerated curing to reach an equivalent age of 1 year. The properties of the specimens at 1-year equivalent age were determined after both standard curing at 23°C and accelerated curing at 60°C. Thus, both the validity of the maturity method and the effect of accelerated curing in ECC were evaluated. Mechanically, compressive and flexural tests were performed, while non-destructive tests such as ultrasonic pulse velocity, rapid chloride ion penetration, and resonant frequency were used to determine ECC properties. As a result, it was determined that all ECC mixtures achieved their ultimate properties in less than a year. Furthermore, it was revealed that ECC retains its distinctive properties even in the ultimate state. Additionally, while accelerated curing led to a slight decrease in all properties compared to normal curing, it contributed to a slight improvement in deformation capacity. Nevertheless, considering the proximity of the results between normal and accelerated curing, it can be concluded that accelerated curing has the potential to be applied in ECC, and based on the findings, the maturity method has the potential to predict the long-term properties of ECC mixtures.
... This is due to reaction of water and Ca(OH) 2 with FA oxides, which form a layer of C-S-H around the FA particle, as a result hindering the access to the innermost oxides, thus, pozzolanic reaction progress slowly [16]. However, the fineness of FA and curing regime have significant influence on mechanical properties development in early ages [17][18][19]. Despite the slow reaction and lower compressive strength at early age, incorporation of FA in concrete reduces the effect of the alkali-aggregate reaction [16,17,20]. ...
Industrial wastes have been widely used worldwide in the construction industry as a pozzolana aiming to reduce Portland cement utilization and to produce economical, energy-efficient, and environment-friendly concrete. Fly ash is a well-recognized and extensively used pozzolana in concrete, whereas pumice has been scarcely used for this purpose. This study intends to experimentally investigate the beneficial utilization of textile industry waste-derived pumice powder (PP) and its comparison with Fly Ash (FA) in concrete. A total of ten mixes of concrete were prepared with PP, FA, and their ternary mixes (PF) by replacing cement with 15 %, 25 %, and 35 %, respectively. The results show that PP possesses higher pozzolanic potential attributed to the presence of higher content of amorphous silica (SiO2) as detected in the X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) test and justified by the Strength Activity Index (SAI). Moreover, the addition of both pozzolana enhances rheological properties along with the workability of fresh concrete. In the case of Mechanical properties, the inclusion of 25 % PP shows better performance among all mixes, whereas FA mixes gain strength in later ages. Furthermore, the hydration products assessed by thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy (FTIR) analysis justified the formation of secondary hydration products and higher pozzolanic potential of PP.
... The partial replacement of cement with FA, and GGBS is thus identified to be impressive; however, particularly at early ages, reduction of compressive strength has been reported [9,10] . The strength decline is observed more seriously when GGBS is utilised at low temperature conditions [9,11] . ...
... As such, elevated temperature curing is a significant factor for the behavior of SCM based concrete and exploration into it is a vital research area. Such recent studies conducted on mortar/concrete that comprised of 30 % of FA and 50 % of GGBS are found in the literature [9,10] . In those investigations, two target compressive strength levels of 30/50 MPa and 10-50°C curing conditions were considered. ...
... In those investigations, two target compressive strength levels of 30/50 MPa and 10-50°C curing conditions were considered. Soutsos et al. [10] study was conducted on mortar subjected to iso-thermal high-temperature curing conditions. Whereas, the concrete specimens reported in Soutsos et al. [9] were subjected to curing temperatures which were matched with those of the internal temperature of real structures. ...
Fly ash (FA) and ground granulated blast-furnace slag (GGBS) are two promising supplementary cementitious materials (SCMs) that can be used in concrete applications. The early age strength development of such concrete is generally slow; however, the strength reduction can fairly be recovered with high-temperature curing implementation. In this study, the compressive strength behavior of binary and ternary concrete mixes those were subjected to 24 hours 50°C and 70°C curing conditions was explored. Two target compressive strengths levels of 30 MPa and 50 MPa were considered and the SCM blend level was 25 %. The results highlighted that, in terms of early strength achievement, the 50°C curing was favourable for the ordinary Portland cement (OPC) and OPC/GGBS mixes whereas the 70°C curing was attractive in the OPC/FA and in the ternary mixes. For the latter age strength, the high temperature curing detrimentally affected for the OPC and OPC/FA mixes whereas a considerable enhancement was noted for the GGBS blended mixes. The overall effectiveness of the high-temperature curing process was higher in the 30 MPa mixes than in the 50 MPa mixes. Meanwhile, the Arrhenious maturity function based strength predictions were identified to be more accurate than its prediction potential reported for past iso-thermal high-temperature curing applications.
... Detailed discussion on the activation energies can be found in [69][70][71] and the procedure for determining activation energies is demonstrated in the ASTM standard practice. The range of active energy is from 33.5 kJ/mol to 63.6 kJ/mol [5,[72][73][74][75][76][77][78][79]. ...
... The main drawback of the above-mentioned functions is the overestimation of later-age strengths of samples because of the adverse influence of high curing temperatures on the long-term strengths [42,75,79,[86][87][88][89]. This is known as the "cross-over" effect, i.e. high curing temperatures cause higher strength at early ages and lower strength at later ages [87,90]. ...
... Abdel-Jawad [99] investigated the effect of curing temperature and water-cement ratio on the long-term strength development and improved the Nurse-Saul maturity function to estimate concrete strength at later ages. Recent studies [75,100] showed that the long-term adverse impact may be observed as early as three days, particularly when elevated temperatures are applied immediately after pouring concrete such as precast concrete elements under steam curing, or in large concrete pours at very early ages as a result of adiabatic temperature rises [101][102][103][104]. Studies by Soutsos et al. [42], Vollpracht et al. [73] demonstrated the inaccuracies of various maturity functions for predicting the strengths of different concrete mixes incorporating SCMs cured with temperature histories of adiabatic and isothermal 50 • C curing, as shown in Figs. 2-4. ...
Quality assurance of concrete used in structures requires in-situ monitoring of early age compressive strength development. Unlike traditional approaches, accurate estimation of early age concrete strength using maturity method can be effectively used to optimise critical construction operations, prevent performance issues and even structural failure. According to the concrete maturity method, concrete strength development is strongly linked to curing temperature and relative humidity. This paper presents an overview of in-situ monitoring strength in concrete structures using the maturity method. Various maturity functions and strength-maturity relationships are summarised. Advanced technological monitoring systems, including both wired and wireless technologies, used for determining concrete strength, temperature, and maturity are discussed with an emphasis on fully automated real-time monitoring systems. Examples of applying the maturity method in monitoring of in-situ strength in various concrete structures are highlighted and compared to the traditional method (e.g. concrete cylinder testing). As a result, the maturity method is a reliable indicator of the in-situ strength to ensure the safety of various structural concrete elements during construction. The paper concludes by stressing some areas where further investigations could provide important insights into the advancements of the field.
... These methods aim to accelerate early strength development and extend the construction season in cold regions; however, these procedures significantly increase the cost and carbon footprint of construction works [4]. In addition, the use of supplementary cementitious materials (SCMs) is usually avoided in concreting works in cold weather due to their slow reactivity and early strength development [2,5]. ...
The use of high-volume ground granulated blast furnace slag (GGBFS) in cement-based materials significantly reduces CO2 emissions. Nevertheless, low curing temperatures are barriers to using environmentally friendly materials in winter construction works. This is mainly attributed to slow GGBFS's reactivity and blends' strength development due to the low alkalinity offered by the slow hydration rate of Portland cement (PC) at low temperatures. In this study, sodium hydroxide was employed to produce dry reactive pre-alkali-activated GGBFS (A-GGBFS), with an intention to increase the system's alkalinity and reactivity. The blended cement paste was prepared with 50% PC replacement with untreated and treated GGBFS, and cured constantly at 0 °C for 28 days. The A-GGBFS accelerated the hydration rate and enhanced the precipitation of hydration products. By adding an optimal NaOH content during the pre-alkali-activation process, the 3 and 28 days compressive strengths of paste increased by 41% and 37%, respectively, gaining a comparable 28 days compressive strength to that measured in a 100% PC-based binder. The microstructural assessments are consistent with compressive strength measurements.
... The Arrhenius maturity relationship was utilised to convert the adiabatic profiles to the required initial temperature of concrete [20], 2003). At this conversion, the activation energy parameter (E) was assumed to be 33.5 kJ/mol based on guidelines found in the literature [21]. ...
... Several studies have reported enhanced resistivity against frost damage, acidic attacks, and carbonation and greater long-term compressive strength in construction materials made with a binder containing SCMs at optimal concentrations compared to their counterparts fabricated with PC only [8,[27][28][29][30][31]. Nevertheless, the slow reactivity of SCMs in PC blends and the reduced early strength development and frost resistance conflict with winter concreting requirements [8]. Soutsos et al. [32] found that decreasing the curing temperature from 20 to 10 • C resulted in a 64% decrease in the compressive strength of three days old PC/GGBFS mortar, while only a 19% reduction was observed in PC mortar. Therefore, the use of SCMs is limited in winter concreting works. ...
The conservation of natural resources, efficient use of industrial side-streams, and reduction of environmental impacts are the main targets of the construction sector worldwide. However, the low ambient temperatures and long harsh winter seasons in northern regions limit the use of industrial side-streams in construction activities under cold weather conditions due to their slow strength development rate. This study aimed to develop an eco-friendly construction material suitable for construction under cold weather conditions using blast furnace slag as a binder and fine aggregate admixed with a calcium silicate hydrate seed accelerator in mortar. Natural sand (NS) was volumetrically substituted with 25%, 50%, 75%, and 100% of granulated blast furnace slag (GBFS) fine aggregate in mortar cured at fluctuating low/freezing temperatures (+5 to −5 °C), representing the late fall and early spring seasons in northern regions. The mortar's compressive strength increased with the incorporation of GBFS aggregate over the first three days of curing and decreased thereafter. A denser interfacial transition zone was captured around GBFS aggregates than NS in the three days old mortars. The deceleration influences of fluctuating low/freezing temperatures on the compressive strength development of mortars were diminished with time. Capillary water absorption increased with higher GBFS aggregate contents. Mortar with 25–50 vol. % GBFS aggregates exhibited greater frost resistance than control mortar with NS only. The incorporation of GBFS aggregate enhanced the mortar's resistance against a sulfuric acid attack. This study demonstrates the potential of GBFS aggregate for use in construction under cold weather conditions.
... Some studies (Soutsos et al., 2013(Soutsos et al., , 2017 have shown that the temperature sensitivity of mixtures containing fly ash is different than normal concretes. Therefore, it is important to investigate the maturity level of concrete and composites produced with other pozzolanic binder materials. ...
... This temperature range was measured in an area with constant room temperature of the specimens for 56 days. Many studies (Boubekeur et al., 2014;Soutsos et al., 2017Soutsos et al., , 2021 have confirmed the temperature effect on strength. High temperature increases the rate of hydration and leads to a less uniform distribution of hydration products. ...
The use of glass fiber reinforced concrete (GFRC) in the construction industry is increasing due to its mechanical and physical properties. Waiting time of concrete in the mold and the removal of the mold at the right time are important in terms of strength. In conventional concretes, maturity models are widely used as a non-destructive method for early strength estimate. In this study, it is aimed to develop an estimate model of flexural and compressive strength in GFRCs using the maturity index method. In this context, glass fiber reinforced concretes were produced at the rates of 0%, 1%, 2% and 3%. Calcined kaolin and acrylic polymer were used as modification materials in the mixtures. Properties such as compressive, flexural, hardness, and shrinkage of specimens were investigated at different ages. The maturity-strength relationships of mixtures at different ages were examined by weighted maturity and Nurse-Saul methods. At the end of the study, two new models were developed to estimate the compressive and flexural strengths of GFRCs, taking into account all the data. The suggested models have been confirmed by examining them on all mix-age groups and comparing them with the literature.
