concrete-bridges-4

concrete-bridges-4

an engineer examines a concrete prism

Engineer Farshad Rajabipour examines a concrete prism being used to study the alkali-silica reaction, which is a major cause of deterioration in concrete structures. Behind him, each white bucket holds four such prisms at high humidity and a temperature of 38 degrees Celsius (about 98 degrees Fahrenheit). Researchers measure expansion of the prisms over time and remove slices of them every few months for microscopic examination.

IMAGE: Curtis Chan