Length Expansion and Cracking of Plain and Reinforced Concrete Prisms Due to Alkali-Silica Reaction

Measurements of length expansion and observations of cracking of plain and reinforced concrete prisms with varying sizes and amount of reinforcement caused by alkali-silica reaction (ASR) are presented. Ends of the prisms were sealed to make the data relatable to existing structural members. The specimens were made with either reactive or nonreactive aggregates and immersed in an alkali solution for one year to accelerate ASR. Visible cracks appeared on reactive specimens after 4 months of conditioning, when length expansion caused by ASR was about 400 microstrain. Expansion of the prisms that contained longitudinal bars was greatly reduced by the reinforcement, and the dominant cracking was oriented in the direction parallel to the reinforcement. Strain of bars caused by ASR was close to yield. The effect of expansion and cracking from ASR on structural behavior of reinforced beams and on mechanical properties of companion cylinders that accompanied these prism tests is reported separately.