Investigation of Potential Alkali-Silica Reactivity of Aggregate Sources in Thailand

Abstract

ABSTRACT:Since the first local evidence of alkali-silica reaction (ASR) was reported in Thailand in 2011, awareness of ASR was raised and the importance of aggregate performance database was recognized, thus an attempt to set up local aggregate database was initiated. As part of the effort to establish the database, a study of potential ASR reactivities was carried out involving aggregates from several current industrial sources in eastern and central Thailand and the results were presented here. Aggregate samples were randomly collected from various sources and tested by two methods; accelerated mortar-bar test (AMBT) and petrographic examination. The types of aggregate sampled included limestone, greywacke, and rhyolitic tuff. The AMBT expansion results indicated that several aggregate types had larger expansion than the threshold of potentially deleterious ASR behavior as suggested by ASTM C 1260 standard. Furthermore, it was found that samples of same aggregate type, although apparently had mineralogically similar compositions, had different reactivities, particularly when sampled from around geological fault zone compared with that taken from the surrounding area and portions of parent rock were observed to be weathered in this area. Thin section analysis revealed evidence of ASR gel at the aggregates' rim, inside the aggregates and in the matrix. These findings suggest possible future ASR problems in Thailand as well as in neighboring countries where the continuity of geology pattern is observed.

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“…Plagioclase mostly showed zonal texture and lath shape. This rock type was widely reported as potentially reactive and previous local studied of this aggregates confirmed the ASR reactivity [1,12] From chemical investigation, MK had higher amount of SiO2 and Al2O3 than that of FA. The XRD result in Fig.…”

“…The rhyolite aggregates from the central part of Thailand, previously identified as a potentially reactive aggregates [12] were used. Rhyolite has been reportedly associated with the ASR occurrence in many concrete structures [23,28,29].…”

“…The guideline suggests that expansion at 14 days of 0.20% or greater normally are indicative of potentially ASR deleterious expansion, and requires further study if it falls in the range of 0.1% -0.2% [30]. Several papers reported rhyolite as the fast reactive volcanic aggregates, but this local rhyolites appeared to be milder in reactive, most likely due to nature variation due to difference in aggregates sources [1,12]. The effect of low percentage of Na2Oequiv.…”

“…The first report [11] on ASR occurrence in Thailand raised the concern on the lack of information on local materials, their behaviors in concrete and the measures for mitigation and prevention. Several sources of aggregate with ASR problem have been found locally, suggesting continuing ASR problems into the future [12].…”

Time-Dependent Deformation of a Concrete Arch Dam in Thailand - Numerical Study on Effect of Alkali Silica Reaction on Deflection of Arch

“…1), the possibility of temperature rise owing to mass concreting and easy availability of moisture in the hardened phase, Delayed Ettringite Formation (DEF) can be suspected (Bouzabata et al 2012). Aggregate in Thailand also has the potential for the Alkali Silica Reaction (ASR) (Yamada et al 2013;Sujjavanich et al 2017), and has been reported in highway bridges (Sujjavanich et al 2012); however, ASR in the dams has not been reported often in Thailand. To check if the dam is affected by DEF or ASR, core samples were extracted from the dam: one from a depth of 0.00-0.300 m (C1) and another from a depth of 0.70-1.00 m (C2) near the right abutment.…”