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Alkali-silica reaction (ASR) and delayed ettringite formation (DEF) are expansive
reactions that can lead to the premature deterioration of concrete structures. Both have
been implicated in the deterioration of numerous structures around the world, including
many transportation structures in Texas. As a result of considerable research advances,...
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Citations
... An abundance of experimental data about such deterioration due to ASR has been reported. The relationships between the compressive strength, (Ahmed et al. 2003;Giaccio et al. 2008;Giannini 2012;Gautam 2017;Martin et al. 2017;Sanchez et al. 2017Sanchez et al. , 2018. elastic modulus, and expansion can be seen in Fig. 25 (Ahmed et al. 2003;Giaccio et al. 2008;Giannini 2012;Gautam 2017;Martin et al. 2017;Sanchez et al. 2017Sanchez et al. , 2018. ...
... The relationships between the compressive strength, (Ahmed et al. 2003;Giaccio et al. 2008;Giannini 2012;Gautam 2017;Martin et al. 2017;Sanchez et al. 2017Sanchez et al. , 2018. elastic modulus, and expansion can be seen in Fig. 25 (Ahmed et al. 2003;Giaccio et al. 2008;Giannini 2012;Gautam 2017;Martin et al. 2017;Sanchez et al. 2017Sanchez et al. , 2018. The compressive strength and elastic modulus decrease with an increase in expansion and the reduction in the elastic modulus is larger at lower expansion levels than that of compressive strength. ...
This paper reviews numerical studies on the effect of expansion and damage due to alkali-silica reaction (ASR) on the mechanical performance of concrete and reinforced concrete at the structural scale level. Previous research on model development that has focused on the performance of RC members or structures is collected and summarized based on how they operationalize expansion progress. The models can be divided into three categories: models that receive the target expansion amount as an input value, models that use expansion curves, and models that calculate the increase in free expansion by considering the kinetic process of ASR. The aim of the model development can be related to either the deformation of the member or the load capacity for static or dynamic load actions. Expansion transfer under confined conditions is characteristic of the ASR problem, and the methods to model expansion transfer are accordingly summarized. Various considerations concerning the effect of ASR expansion and associated damage on the concrete constitutive laws are also studied. Expansion transfer under multi-axial stress states can be accurately reproduced by the modeling of expansion redistribution and volumetric expansion reduction under stress conditions. There are diverse methods to model the resultant deterioration of mechanical properties, but the primary method is by reducing the strength and elastic modulus according to empirically determined relationships. The ideal modeling approach is still under discussion because the effect of the anisotropic cracking state on the anisotropic mechanical response still requires further study. Finally, current problems of assessment of ASR-damaged concrete structures were discussed, and the significance of the causal correlation between macroscopic expansion behavior and microscale factors was suggested.
... Therefore, information on expansion cracks is important to assess the decreasing trend of the mechanical properties. Considering the reduction in compressive properties due to ASR and DEF expansion, the relationship between the expansion under stress-free conditions and compressive properties has generally been evaluated (Ahmed et al. 2003;Brunetaud et al. 2008;Giaccio et al. 2008;Bouzabata et al. 2012;Giannini 2012;Shamaa et al. 2014;Gautam et al. 2017;Martin et al. 2017;Giannini et al. 2018;Sanchez et al. 2018). However, there are no experimental data on the anisotropy of the mechanical properties due to DEF expansion although the orientation of a crack has been observed (Kawabata et al. 2021). ...
The involvement of expansion cracks in reducing compressive properties was experimentally evaluated. Concrete specimens deteriorated by delayed ettringite formation were subjected to three loading patterns (monotonic, stepwise cyclic and sustained loadings) and digital image correlation was performed to observe the behavior of expansion cracks during compressive loading. As a result, while significantly large plastic deformation was generated in the pre-peak, the reduction in compressive properties was hardly influenced by the loading patterns. The elastic strain, obtained from the loading hysteresis, increased linearly until a maximum load was reached. Consequently, two possible stress-bearing mechanism of concrete damaged by delayed ettringite formation under compressive stress was proposed to explain the development of elastic and plastic strains and the reduction in the compressive property.
... As such, it has been observed that the cores extracted from non/less unconfined directions exhibited considerably lower compressive strength (i.e., 9-25 %) and modulus of elasticity (i.e., 10-30 %) than those cored from more confined areas [4,7,8,[28][29][30][31]. Such observation could be attributed to the existence of a higher number of ASR-induced cracks in the specimens retrieved from un/less reinforced areas [8,33,35]. Although the above results are very interesting and indeed demonstrate the effects of internal restraint on ASR damage development, only a handful of studies (e.g., [36][37][38][39][40]) have been conducted on the externally restrained ASR-affected concrete elements. ...
The multi-level approach coupling of mechanical (i.e., Stiffness Damage Test -SDT) and microscopic (i.e., Damage Rating Index -DRI) testing procedures, was found to be promising for evaluating the condition of ASR-affected concrete elements under unconfined and internally confined conditions. Yet, only a few studies investigated the effect of external confinement (i.e., CFRP wrap) on ASR-induced damage. Thus, this study aims to study the impact of various external confinement conditions (i.e., none, 1 ply CFRP and 2 plies CFRP) on ASR-induced damage. One hundred and seventy concrete specimens incorporating distinct reactive aggregates (coarse and fine aggregate) and confinement conditions were fabricated, stored in an environmental chamber, and monitored over time. Upon reaching the given expansion levels, a multi-level assessment was conducted. The results show the mitigation nature of confinement against ASR-induced expansion as well as yielding damage transfer according to the confinement condition. Moreover, different crack features and orientations, as well as mechanical degradation, are observed in restrained specimens, which confirms that ASR exhibits different damage developments under “free expansion” and externally restrained conditions.
... Introduction damage levels [4][5][6][7] . Nonlinear resonance acoustic spectroscopy (NRAS) shows a high sensitivity to ASR damage development by measuring the fundamental resonance frequency change with vibration or strain magnitude [7][8][9][10][11] . ...
... Concrete property changes and microcracking damage will affect elastic wave propagation in concrete. Ultrasonic parameters including wave velocity and amplitude (attenuation), have been investigated for ASR damage assessment in concrete 6,[16][17][18] . With the increase of crack density in concrete, both the ultrasonic velocity and the amplitude decrease due to wave scattering and absorption. ...
... Saint-Pierre et al. 16 found the ultrasonic wave velocity dropped about 8% when the ASR expansion reached 0.2%; while in another study, Rivard and Saint-Pierre 17 found the velocity only dropped about 4% in concrete prisms at the same ASR expansion level. Giannini et al. 6 investigated multiple NDT test methods, including ultrasonic pulse velocity (UPV), impact-echo, surface wave tests, and the resonance test for much larger ASR expansion ranges (0.3% ∼ 1.6%). It was found that the UPV results showed up to 20% decrease at higher expansions for different aggregates, but it was very difficult to obtain consistent UPV measurements. ...
This article presents continuous monitoring results of alkali-silica reaction (ASR) development in concrete specimens for over 400 days using ultrasonic testing and expansion measurements. Eight concrete specimens with nonreactive aggregate (Control), reactive coarse aggregate, and reactive fine aggregates were cast with two reinforced confinement conditions. The specimens were conditioned in an environmental chamber with high temperature and humidity (38°C and 90% relative humidity) to accelerate the ASR development. A multichannel ultrasonic monitoring system was developed to collect ultrasonic signals automatically, and the expansions in three directions were measured periodically. Results showed that the relative velocity change could detect the ASR initiation in all reactive specimens and show a correlation with expansion in the early stage. However, these correlations are inconsistent for different ASR specimens, and the velocity change becomes less sensitive to ASR damage in the late stage (after 300 days). Irrecoverable velocity drop was observed during every chamber shutdown period, especially in specimens with higher levels of ASR damage. This phenomenon suggests that the nonlinear ultrasonic response caused by the ambient temperature variation may indicate the ASR damage.
... In addition, the effects on 47 the mechanical properties due to cracks caused by drying shrinkage, alkali-silica reaction (ASR), 48 and delayed ettringite formation (DEF) have been investigated by many researchers. Moreover, the 49 crack propagation process due to shrinkage [13][14][15][16][17][18] or expansion [19][20][21][22] and its influence on 50 mechanical properties [13, 17, 18,[23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] have been elucidated in previous studies. Particularly, for 51 ASR expansion, it was reported that the expansion cracks exhibit directionality under constraint 52 conditions, and their influence on mechanical properties varies with the crack angle of the loading 53 ...
In this study, the reduction mechanism of the compressive properties of concrete with mechanically induced crack of different widths and angles was evaluated using a discrete mechanical model. Analytical investigations were conducted along with experiments to visualize the change in the stress transfer in a cross-section due to the presence of a primary crack. Based on the visualization of the stress distribution in the cross-section using a rigid body spring model (RBSM), the mechanical response of the primary crack under compressive stress and the reduction mechanism of compressive strength and elastic modulus were elucidated. Based on the results, it was concluded that the RBSM could reproduce the reduction in compressive strength and maximum tangential stiffness of cracked concrete with different crack widths and angles. Furthermore, the reduction mechanism of strength and stiffness due to the presence of a primary crack was newly elucidated considering the influence of the angle of the crack.
... Many researchers experimentally showed that the compressive strength and elastic modulus dramatically decrease in the presence of expansion cracks caused by ASR [19][20][21][22][23][24][25][26][27]. The crack propagation process inside the aggregate with the evolution of the ASR expansion proposed by Sanchez et al. [15] is related to the reduction in compressive properties, as shown in Fig. 2. At an expansion of 0.05%, sharp cracks and onion skin cracks are generated from within the aggregate, and the elastic modulus is reduced up to 70% of that of normal concrete, while the compressive strength does not change. ...
... (2) Comparison with compressive behavior reduction due to real ASR damage Fig. 24 shows a comparison between the compressive properties of the ASR series and previous experimental results [19][20][21][22][23][24][25][26][27]. According to this figure, the compressive strength and elastic modulus at a set expansion (0.12-0.20%) decreased up to approximately 75% and 45%, respectively, as indicated by the grey area. ...
... The proposed reduction mechanism for the compressive properties presented in this paper will be applicable in Fig. 24. Comparison of the compressive behaviors for the ASR series with the experimental results [19][20][21][22][23][24][25][26][27]. ...
This study discusses the mechanism for the changes in the compressive properties of internally cracked concrete due to expansion phenomena. The internal crack patterns due to alkali-silica reaction (ASR) and delayed ettringite formation (DEF) are reproduced using the model concrete with artificial cementitious aggregate. The compressive behaviors are clarified using a uniaxial compressive test with digital image correlation. As a result, in terms of ASR, the trends for reduced mechanical properties in model concrete differ from the expansion phenomena under stress-free condition and the anisotropy of change in mechanical properties due to the aggregate crack orientation changes is observed. For DEF, the reduction in mechanical properties is independent of thickness of a debonding crack. Consequently, the mechanism for reduction in compressive strength and elastic modulus by the aggregate cracking and gap formation due to ASR and DEF based on the compressive stress transfer path at the cross-sectional area was proposed.
... The above differences in the mechanical responses of distinct directions of confined concrete might be due to the amount and orientation of ASR-induced cracks in the cores retrieved perpendicular to the main rebars [18,28,29]. In this regard, Zahedi et al. [18] observed that most of the ASR-induced cracks are parallel to the main restrained direction (i.e., reinforcement direction) in cores extracted parallel to it, while being perpendicular to the main rebars in cores retrieved perpendicularly to the main restrained direction. ...
The multi-level assessment, combining microscopic (i.e., Damage Rating Index) and mechanical (i.e., Stiffness Damage Test) techniques, has been effectively used to appraise the deterioration cause by alkali-silica reaction (ASR) in unconfined concrete. However, the impact of restrainment on ASR-induced deterioration originated from reactive fine and coarse aggregates has not been fully explored. This study intends to evaluate the effect of the confinement degree and reactive aggregate type on ASR damage development through the multi-level assessment. Twenty-four concrete blocks incorporating two different reactive aggregate types (fine and coarse) and three confinement configurations (unconfined, 1D, and 2D) were produced and monitored over time. Upon reaching the desired expansion levels (0.08% and 0.15%), cores were retrieved from three main directions (vertical, longitudinal and transverse) and the multi-level assessment was performed. Results indicate that ASR-induced expansion and damage are influenced by the reactive aggregate type, confinement configuration and coring direction.
... The modulus of elasticity presented a drop of about 80% with the high DEF induced expansion (over 1%) for concrete with Type III cement ( Figure 13) whereas expansions up to 0.25% did not impact this property in the presence of pozzolanic cement ( Figure 14). According to [19], [58], deleterious effects on the modulus of elasticity can arise even before the occurrence of significant expansions. ...
... In the literature, some researchers agree that DEF expansions negatively affect the mechanical properties of concrete [19], [24], [58]. However, some studies pointed to negative results of compressive strength (drop of 50%) when the expansion values are remarkably high, next to 1.50% [1], [3], [23]. ...
Delayed Ettringite formation (DEF) is an internal expansive reaction that can damage concrete. DEF is strongly influenced by the temperature, above about 60-65°C, and other factors involving cement chemistry especially, but also its physical characteristics. The exposure environment over time also promotes a condition to increase deterioration from DEF. Expansions results from secondary ettringite formation are progressive and can lead concrete to microcracking impacting its performance and durability over time. Several concrete structures are pointed to be severely attacked by DEF, and test method as well a better comprehension on this pathology is necessary to promote specific and proper preventive measures to avoid future damages. Furthermore, compared to alkali-silica reaction, DEF occurs more readily and aggressively, and sometimes prematurely, depending on several factors, such as type of cement, concrete mix design, exposure conditions, among others. This paper involves an overall analysis of the behavior of concretes with two types of Portland cements (High early-strength cement and a Portland pozzolanic cement, with fly-ash) in relation to DEF process. Several data from a laboratory study where DEF was induced through a specific thermal curing procedure are presented and discussed. The analyses involved the assessment of physical, mechanical, and expansive properties besides microstructural monitoring of samples from concretes over time. These experiments allowed detecting high values of expansions from DEF (up to 1.2%) in the concrete without fly ash. The mechanical properties were severely impacted from this deleterious process; as expansions increased, losses in the mechanic and elastic properties were verified. Expansion levels in the order of 0.5% prompted remarkably high reductions and, at about 1% the losses were relevant for both strengths (tensile and compressive) and modulus of elasticity, of 60% and 80%, respectively, in the presence of cement without fly-ash. Concrete microstructure has indicated massive formations of ettringite as well as micro-cracking and the fragility of the cement matrix because of DEF. On the other hand, expansion up to 0.2% did not promote important negative effects on the properties of concrete, especially with the pozzolanic cement tested. Furthermore, an overall approach with several correlations between physical and mechanical properties was taken to obtain different levels of deterioration for a concrete presenting DEF.
... Jones [41] observed that the modulus of elasticity of cores extracted perpendicular to the main confinement direction was significantly lower than those cored parallel to it. Such an observation can be due to the presence of higher amount of ASR cracks in cores extracted perpendicular to the main confinement [42][43][44]. Likewise, Gautam et al. [34], after conducting research on the effect of distinct confinement configurations (none, uniaxial, biaxial and triaxial) on the mechanical degradation of ASR affected concrete, observed that concrete members under triaxial conditions display lower mechanical degradation than all the other confinement configurations. ...
The Stiffness Damage Test (SDT), a mechanical and cyclic test procedure, has been successfully used to appraise alkali-silica reaction (ASR) deterioration under unrestrained conditions. However, the effects of confinement on ASR-induced mechanical damage have not been fully investigated. This work aims to understand the influence of confinement on ASR-damage development through mechanical protocols (SDT and compressive strength). Eighteen concrete blocks incorporating a highly reactive coarse aggregate and displaying distinct reinforcement configurations were fabricated and monitored over time. Two expansion levels were selected for analysis (0.08% and 0.15%) and once reached, cores were extracted from three different directions (longitudinal, transverse and vertical) and the mechanical tests conducted on those. Results show that the SDT is a reliable procedure to assess damage under restrained conditions. Moreover, ASR-induced mechanical distress varies according to the coring direction and confinement configuration. Finally, microscopic analyses validate the mechanical responses obtained as per the distinct coring orientations.
... Therefore, more experimental research is essential in order to comprehend the ASR behaviour of reactive aggregates when used with alkali activated binders. Moreover, the CPT is usually considered more reliable than the AMBT since the samples are exposed to more realistic environmental conditions and alkali leaching is minimised due to the larger cross section of concrete prism samples [18,19]. In the AMBT, mortar bar specimens are immersed in 1 M sodium hydroxide (NaOH) solution at 80°C, which is considered to be highly aggressive and can produce unreliable results [20]. ...
This paper examined the alkali–silica reaction (ASR) of waste glass cullet in alkali activated concrete (AAC), using the ASTM C1293 concrete prism test (CPT), in comparison to that in ordinary Portland cement (OPC) concrete. Test results showed that the 1-year expansions of OPC concrete and ground granulated blast furnace slag (GGBFS) based AAC were 0.21% and 0.13%, respectively, which exceeded the 0.04% limit of the ASTM standard. However, both fly ash (FA) based AAC and FA-GGBFS blended AAC showed 1-year expansions below the recommended limit. The AAC with 60% GGBFS and 40% FA showed the lowest 1-year expansion of all the concretes studied. The expansions showed consistency with the physical appearance, porosity and hydroxyl ion (OH–) concentration in the solution extracted from the concrete samples. Moreover, a detailed microstructural investigation revealed severe deterioration of glass aggregates when used in both OPC concrete and alkali activated GGBFS concrete due to the formation of calcium (Ca) rich expansive ASR gel. However, the gels formed at the aggregate paste interface of alkali activated FA and FA-GGBFS concrete were not typical ASR gels, since they contained high Al/Si ratios and low Ca/Si ratios.
