HIGH-STRENGTH REDUCED-MODULUS HIGH PERFORMANCE CONCRETE (HSRM-HPC) FOR PRESTRESSED CONCRETE TIE APPLICATIONS

摘要

A High-Strength Reduced-Modulus High Performance Concrete (HSRM-HPC) for use in prestressed concrete rail ties has been developed by the authors. The HSRM-HPC material was originally considered for highway bridges but was rejected because of the accidental finding of the low modulus of elasticity. It is shown that the elastic modulus of the HSRM-HPC is reduced as much as 50% compared to the conventional HPC of the same strength while preserving all other properties of the conventional HPC. The use of the more flexible HSRM-HPC in concrete ties leads to reduced stress amplitudes and regularized stress fields at the rail seat area and the middle segment of the tie, which are the two most critical areas of tie failure. This work discusses the development and characterization of the HSRM HPC material, as well as current work on the performance assessment of such ties. The material development, material characterization, and performance assessment is conducted through experimental testing and computer simulations. The benefits of HSRM-HPC ties are quantified and discussed.