Experimental Study on Prestress Loss of Prestressed Concrete Beam under Alternating Loads

Abstract

To investigate the prestress loss of prestressed concrete beam under alternating loads, two post-tensioned bonded prestressed concrete beam models were designed and fabricated based on the similarity theory. The constant amplitude test was performed to analyze the stress state of the prestressed tendon, and the prestress loss under alternating loads was theoretically calculated based on both CEB-FIP 1990 model code and the equation proposed by Balaguru. The test results suggest that prestress loss is produced under alternating loads. Throughout the entire loading process, the prestress loss can be roughly divided into bridge engineering; prestressed concrete beam; experimental tests; prestress loss; alternating load; CEB-FIP 1990 model code three stages. The prestress loss strain values calculated by CEB-FIP 1990 model code and Balaguru’s equation are both smaller than the measured value. It is therefore recommended to determine this value based on the relevant experimental data. The prestress loss under alternating loads is calculated by referring to the formula for the prestress loss resulted from concrete shrinkage and creep specified in China’s current “Code for design of concrete structure”.