Effect of Multiaxial Stresses on Alkali-Silica Reaction Damage of Concrete

Abstract

Alkali-silica reaction (ASR) causes expansion, cracking, and degradation of the mechanical properties of concrete. While ASR performance of unrestrained concrete specimens is relatively well understood, the ASR performance of concrete structures is complicated by co-acting stresses. This paper investigates the influence of sustained multiaxial stresses on the response of concrete undergoing ASR. Reactive concrete cube specimens (with three replicates) were subjected to different stress states, from no-stress to triaxial stress, and were subjected to accelerated curing until the exhaustion of expansion potential. The specimens were periodically core-drilled and the cores were tested for compressive strength and modulus of elasticity. Stress state influenced the degradation of mechanical properties and ASR-affected concrete behaved as an orthotropic material. ASR cracking was portrayed along three mutually perpendicular planes of multiaxially loaded concrete by performing damage rating index analysis. Surface cracking was also monitored. Triaxial confinement contributed to having reduced volumetric expansion and less cracking.

Structural Performance Evaluation and Monitoring of Reinforced Concrete Shear Walls Affected by Alkali-Silica Reactions

“…As shown in Fig. 17, the volumetric expansion of the two specimens was nearly identical, showing the ASR induced volumetric expansion to be independent of confinement conditions when one direction is free from confinement, as mentioned elsewhere (Multon and Toutlemonde 2006;Gautum et al 2017;Hayes et al 2018). The strains observed in the flange walls and upper/lower slabs were small, 555 to 1129×10 -6 and 93 to 166×10 -6 , respectively.…”

Time-dependent Effect of Expansion due to Alkali-silica Reaction on Mechanical properties of Concrete

“…In this section, the previously reported measurement data on the mechanical properties of concrete after ASR are collected (Giaccio et al 2008(Giaccio et al , 2015Kagimoto et al 2014;Ahmed et al 2003;Swamy et al 1998;Gautam et al 2017aGautam et al , 2017bLiao et al 2020;Esposito et al 2016;Abd-Elssamd et al 2020) to verify the trend observed in the previous section and discuss whether the progressing of material age can have a positive effect on the mechanical properties. Table 4 lists the previously reported experimental details.…”

“…And uniaxial restraint could lead to higher stiffness because the measured expansion was smaller compared to specimens under free expansion. The confinement effect on mitigating damage by reducing crack-opening was also confirmed by Gautam et al (2017b). Morenon et al (2019) considered the positive role of ASR in flexural performance due to chemical prestress by ASR gel in reinforcement direction of RC beam, while authors experienced that stiffness of RC slab affected by ASR expansion cannot be explained only by chemical prestress force by ASR gel.…”

“…14(viii), the elastic modulus decreased first from week 9 to week 39 and then recovered until the end of test duration (week 78). In the experiment by Gautam et al (2017b), a significantly high compression force (3.9 MPa, 9.6 MPa) was applied to confine the expansion of the specimens. In conclusion, confinement could modify the crack orientation and reduce crack width, thus improving the mechanical properties.…”

“…14(x). The stress generated by the fiber to close the cracks is considerably lower than that induced by external forces such as the one applied in Gautam et al (2017b). Contrastingly, fiber could also reduce the number of cracks, which has already slowed the deterioration in stiffness by ASR damage in the expanding procedure.…”