Alkali–silica reaction (ASR)—performance testing: Influence of specimen pre-treatment, exposure conditions and prism size on alkali leaching and prism expansion

Alkali–silica reaction (ASR)—performance testing: Influence of specimen pre-treatment, exposure conditions and prism size on concrete porosity, moisture state and transport properties

“…One reason for the observed reduction in suction porosity is assumed to be further hydration, in particular of the fly ash, making the paste denser. Additionally, the final expansions are less for these two binders compared with the two CEM I binders with higher w/c (discussed in [25]). …”

“…Knowing that the critical RH limit for developing ASR is in the range of 80-90 %, depending on several factors as discussed by Larive et al [32], it is likely that the rather low RH revealed for the "dense" binder after 4 weeks of exposure and maybe also for the "fly ash" binder contributes to reduce the rate and extent of ASR, in particular for the test series exposed to 38°C (further discussed in [25]). For all test series with the CEM I binders with higher w/c (0.45 or 0.60), except for the sealed test series, RH is regarded to be sufficient for ASR to develop.…”

“…In a separate paper [25], results from the periodic measurements of alkali leaching from the concrete prisms, concrete prism expansion and dynamic E-modulus are presented and evaluated, together with main findings from some of the supplementary tests (see Section 2.4). Additionally, consequences for ASR test procedures are discussed.…”

“…Additionally, the rate and amount of alkali leaching from concrete prisms (measured for all test series at the same point in time as the expansion measurements) are properly discussed in [25].…”

“…• Microstructural analysis (on polished sections ("PS") and thin sections ("TS"), in addition to use of scanning electron microscope (SEM) -see [25] and [44])…”