Durability of wheat straw ash concrete to alkali-silica reaction

This study investigated the effect of wheat straw ash on the durability of concrete to detrimental alkali-silica reaction. Three wheat straw ash levels were considered in the study: 5, 10 and 15% as a partial replacement of cement. The other experimental parameters investigated in the study were: w/b ratio (0·5 and 0·6) and initial curing type (moist and autoclaving). Crushed Pyrex glass was used as reactive fine aggregate in the study. After the initial curing, the concrete specimens were immersed in a 1 N NaOH solution tank at 40°C to accelerate the deleterious alkali-silica reaction. The alkali-silica reaction deterioration was assessed by measuring the expansion of concrete prisms and the reduction in compressive strength. The study showed that the wheat straw ash concrete was more durable to alkali-silica reaction damage than the control concrete. The durability of wheat straw ash concrete increased with increasing the wheat straw ash content. The wheat straw ash concrete with w/b ratio of 0·5 showed higher durability to alkali-silica reaction damage in comparison with wheat straw ash concrete with w/b ratio of 0·6. The autoclaved wheat straw ash concrete showed generally similar performance to alkali-silica reaction deterioration compared to the moist-cured wheat straw ash concrete.