High-Strength, Reduced-Modulus, High-Performance Concrete for Prestressed Concrete Crosstie Applications
High-performance concrete (HPC) with early strength development is the material of choice for fabricating prestressed concrete railroad ties. However, the higher strength of HPC results in significantly higher elastic modulus values and increases the rigidity of the tie, leading to higher amplitude stresses and stress gradients, and eventually to premature cracking and deterioration of the railroad ties. This report presents material development and characterization studies of high-strength, reduced-modulus (HSRM) concrete and its application for concrete railroad ties. Prototype ties have been fabricated and qualified through testing and computer simulations. The fabrication of the HSRM ties did not affect the current fabrication practices and cost. This study shows that HSRM ties outperformed standard concrete ties by (a) showing smoother stress distribution, (b) delaying the initiation of cracks, (c) redistributing the load after first cracking in an effective manner, and (d) failing at higher ultimate loads. Researchers suggest HSRM concrete is a cost-effective alternative concrete to the industry standard concrete used in ties and has the potential to increase its tie service life.