Early-age responses of railway prestressed concrete sleepers to creep and shrinkage

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Abstract

Prestressed concrete have been commonly used for manufacturing railway sleepers since 1940s because of many superior advantages in high endurance performance, maintainability, sustainability, and construction resilience. Prestressed concrete has overcome the low tensile strength in concrete by introducing a prestressing force along the high-strength steel tendons/wires to enable cross sectional compression. However, the short-term performance of prestressed concrete members largely depends on creep and shrinkage responses at early age. The effects of time-dependent phenomena on prestressed concrete sleeper are investigated in this paper. In the past, many investigators had proposed various material models to predict creep and shrinkage but those applications were mostly based on general reinforced concrete concept. The popular uses of prestressed concrete have led to a concern of practitioners whether quality control of concrete at early age should also be focussed. Due to high initial elastic shortening in prestressed concrete, the creep and shrinkage effects at early age plays a critical role over the longer term performance. This study investigates and compares a variety of methods to evaluate creep and shrinkage effects in railway prestressed concrete sleepers. Comparison between design codes of European Standard EUROCODE2, American Standard ACI, and Australian Standard AS3600-2009 provides the insight into the time-dependent performance of railway concrete sleepers. The outcome of this study will help railway and structural engineers to better design and control early age quality of concrete sleepers, improving their life expectancy.

Details

Original languageEnglish
Title of host publicationProceedings of the 2nd International RILEM/COST Conference on Early Age Cracking and Serviceability in
Subtitle of host publicationEAC02
Publication statusPublished - 14 Sep 2017

Keywords

  • creep, shrinkage, elastic shortening, prestress losses, prestressed concrete, railway sleepers, crossties, Eurocode, ACI, AS3600-2009