Susceptibility of Fly Ash Concrete to Damaging Alkali Silica Reaction - Performance Testing Conditions

In terms of the damaging alkali silica reaction (ASR), the use of fly ash in concrete leads to important advantages such as a denser concrete microstructure or the incorporation of alkalis in the products of the pozzolanic reaction. Thus a reliable assessment of the ASR susceptibility of fly ash concrete compositions requires modification of approved ASR performance tests at 60 °C. Investigations on concrete porosity and pore solution composition show why the standard testing procedure for pure Portland cement concrete lead to incorrect assessment. At the same time, the results indicate that a longer pre-storage time (28 d at 20 °C) before the actual performance test is essential to produce reliable assessments.     «

In terms of the damaging alkali silica reaction (ASR), the use of fly ash in concrete leads to important advantages such as a denser concrete microstructure or the incorporation of alkalis in the products of the pozzolanic reaction. Thus a reliable assessment of the ASR susceptibility of fly ash concrete compositions requires modification of approved ASR performance tests at 60 °C. Investigations on concrete porosity and pore solution composition show why the standard testing procedure for pure...     »