EXPLORATION OF ALTERNATIVES FOR PRESTRESSED CONCRETE MONOBLOCK CROSSTIE DESIGN BASED ON FLEXURAL CAPACITY

Recent North American railway trends, signify a transition to increased axle loads and higher train speeds. The use of concrete crossties is common practice in these applications for a variety of reasons, including higher load-carrying capacity and improved ability to maintain proper track geometry. Currently, prestressed concrete monoblock crossties share many geometric and structural properties regardless of manufacturer. For multiple reasons, some manufacturers are investigating the potential benefits of new geometries for crosstie design. One alternative currently being explored is to modify the length and cross-section of the crosstie in order to increase the flexural capacity while using a similar amount of material. In this paper the benefits and implications of these changes will be explored both through theoretical calculations and laboratory testing. This alternative design will be evaluated and compared to concrete crossties representative of those currently found in North America. Comparison of the designs will be based on structural cracking at critical locations along the crosstie. These results were used to provide guidance on critical design parameters for concrete crossties capable of withstanding future loading and performance demands.