Effect of Stress Level on Creep and Creep Recovery of Lean Mass Concrete

摘要

A test program was conducted to investigate the relationship between the intensity of sustained load and the creep of a typical mass concrete with low cement content similar to that used in concrete dams. Sealed mass concrete cylinders were loaded in compression at ages of 28 and 90 days; the loads were sustained for over a year and creep was measured periodically. Creep of concrete loaded at 28 days is proportional to sustained stress less than 15% of the 28-day compressive strength. Increases in creep deformations are noted at stresses greater than 15%. Concrete loaded at 90 days exhibits creep proportional to sustained stress to 22% of the 90-day compressive strength. Creep recoveries of sealed concrete specimens unloaded after 400 days of continuous compression are proportional to sustained stress, regardless of the concrete age at load application. (Author)