This project studied an innovative concept for introducing, monitoring, and adjusting prestress forces within concrete crossties in the field using “Adaptive Prestressing System (APS)”. The new concept is designed to address problems associated with varying support conditions and high prestress force (e.g. splitting cracks). With the use of a fuse made of innovative prestressing materials, named shape memory alloys (SMA), APS is designed to introduce prestress in specific areas of concrete as needed in the required region.

The project: 1) examined the concept of using APS in crossties using finite element analysis, 2) conducted material testing and characterization on various components of the APS, and 3) conducted 1/2-scale testing of crosstie equipped with APS. The project objective was to help improve the safety, efficiency, and performance of railroad tracks by providing an easy, reliable, and cost-effective solution for the severe concrete crosstie cracking problems attributed to under- or over-stressing of crossties due to variations in loading, support, and climate conditions.  

The final report is available.