Experimental investigation on the mechanical properties and damage evolution of steel-fiber-reinforced crumb rubber concrete with porcelain tile waste

Abstract

The utility of crumb rubber concrete (CRC), a green concrete containing waste tire rubber particles as partial replacement for natural fine aggregate, is limited by its lack of strength. It is found that the addition of steel fibers is a solution to the limitation. This study proposes using porcelain waste coarse aggregates and steel fibers to improve the cubic compressive strength and flexural strength of CRC and avoid the pollution caused by porcelain waste. Porcelain waste was incorporated at replacement percentages of 25%, 50% and 100% by volume. Steel fibers were incorporated at volume fractions of 1% and 1.25%. The cubic compressive strength and flexural strength of CRC, steel-fiber-reinforced CRC (SFRRC) and SFRRC with porcelain waste were then tested. The results obtained show that the strengths of CRC are greatly improved by the incorporation of steel fibers and 25% porcelain waste. With the increase in porcelain waste content, the strengths of SFRRC containing porcelain waste decrease. Scanning electron microscopy was then conducted and the findings show that the strengths decrease at high porcelain waste content due to the weak bond between the glaze of porcelain waste and the cement matrix. The fracture processes of three types of concrete under four-point bending were monitored by using acoustic emission (AE) technique. Based on the AE data, the parametric analyses, including cumulative hits analysis, b-value analysis and RA-AF analysis, were performed for three types of concrete and presented characteristics of damage evolution of them. This paper provides information about the mechanical properties and fracture process of a new type of green concrete that can be used in bending members of concrete structures.