Structural performances of an eco-friendly prestressed concrete sleeper

Abstract

This study focuses on investigating structural performances of a newly developed eco-friendly prestressed concrete sleeper for railway tracks in South Korea. An eco-friendly concrete has been developed by authors at the Korea Railroad Research Institute (KRRI) with the aims of reducing carbon dioxide (CO2) emissions and finding a replacement of natural sand for fine aggregate. Direct and indirect CO2 emissions are one of the main environmental issues in the concrete industry. Reducing the amount of cement usage is beneficial to address the issue of CO2 emissions in the concrete industry. Another environmental issue in the concrete industry in South Korea is the shortage of natural sand as a fine aggregate. So there is a need for finding a replacement of natural sand. The authors utilized two types of recycled industrial byproducts (slags) to handle the environmental issues of railway prestressed concrete sleepers: (1) ground granulated blast furnace (GGBF) slag, which replaces 30% of Portland Type III cement and (2) electric arc furnace (EAF) oxidizing slag, which entirely replaces natural fine aggregate. With the recycled industry slags, an eco-friendly concrete was developed with a high initial compressive strength at prestressing release (<24h) and 28-day compressive strength, which are essential properties for manufacturing prestressed concrete sleepers. Herein, required laboratory tests such as static test, dynamic test, fatigue test, and vertical test for fastening components are carried out to evaluate structural performances of the eco-friendly prestressed concrete sleepers according to international and domestic prestressed concrete sleeper standards. Experimental results demonstrate that the eco-friendly prestressed concrete sleeper not only satisfies the structural requirements of prestressed concrete sleepers in accordance with the international and domestic standards, but also shows superior structural performances compared with those of normal prestressed concrete sleepers.