What is it about?
This test method is intended to detect the alkali silica reactivity of an aggregate (28-45 days) or assess the effectiveness of mitigation measures of SCMs (75-90 days) in terms of measuring length change of a cylindrical concrete specimen immersed in a soak solution with a chemistry equal to the pore solution of the tested concrete specimen at 60ºC (140ºF). ACCT is able to test concrete specimens at varying alkali loadings (i.e., alkali loading = 4.5 lb/yd3 as well as higher and lower than 4.5 lb/yd3). This test has been accepted as an AASHTO provisional standard and scheduled to be published in April 2021.
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Why is it important?
This test (ACCT) is intended to provide results similar to the concrete prism test (CPT, ASTM C1293) or modified concrete prism test (MCPT, T 380). This test is performed differently than the CPT or MCPT method. The test conditions such as using LVDT to measure length change in a closed system, soak solution = pore solution, use of as-received aggregate, alkali level close to field level of alkalinity (no alkali boosting) increase the reliability of this test. As ACCT doesn’t suffer from alkali leaching and ensures negligible alkali penetration from soak solution into the concrete specimen, the effect of cement alkalis as well as soluble alkali contributions from SCMs on ASR expansion can be detected by the ACCT method.
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Read the Original
This page is a summary of: Accelerated Concrete-Cylinder Test for Alkali–Silica Reaction, Journal of Testing and Evaluation, January 2015, ASTM International,
DOI: 10.1520/jte20140334.
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