Evaluation of Prestress Cable Strain in Multiple Beam Configurations

摘要

A system to measure prestress cable strain was fabricated, software written, and the unit calibrated. Strain measurements were made by attaching four Linear Variable Differential Transformers (LVDT) to prestress cable before they were stressed. Due to limited test data and problems with the data collection, no conclusions were drawn about the loss of cable tension due to cable depressors. Due to the cooperation between the Kansas Department of Transportation and the supplier of the prestrssed beams, this project resulted in a change in the casting bed configuration which will likely result in more consistent prestress cable tension. The casting bed configuration was changed from casting five beams simultaneously to casting three beams simultaneously. Other linear movements, such as bridge beam deflection, can be measured using the method and instrumentation developed in this project.