Improving serviceability of concrete railroad ties using prestressed AFRP strands

Abstract

Prestressing with steel strands has been a key aspect in providing the required strength and durability for railroad ties (sleepers) needed to resist the loads on heavy haul lines in many countries. In spite of their improved durability in contrast to timber ties, a major flaw seen with concrete ties is deterioration due to the environmental or fatigue loading. Another issue found in concrete ties, not found in timber, is the electrical conductivity. The objective of this research is to design and to evaluate a class of concrete railroad ties utilizing aramid fiber reinforced polymer (AFRP) strand as the prestressing material. AFRP prestressed ties were constructed and tested for serviceability and strength following the guidelines provided by the American Railway Engineering and Maintenance-of-way Association (AREMA). Results demonstrated that AFRP strands are a potential substitute for steel strands. Some detail improvements may be necessary to mitigate cracking, this can be achieved by using smaller diameter strands.