Crack-damage mitigation of RC one-way slabs with a strain-hardening cement-based composite layer

Abstract

This paper describes a method to replace part of the concrete at the tensile bottom of one-way slabs with strain-hardening cement-based composite (SHCC) in order to mitigate cracking and improve the durability of the reinforced concrete (RC) members. Specifically, this paper explores the structural application of an expansive SHCC to mitigate crack damage in RC flexural members. The results of tests on eight simply supported RC slabs are described. The effects of the type of SHCC used and the SHCC layer thickness on the first-crack load, ultimate flexural load, crack width and spacing, and the load–deflection relationship of one-way slabs are investigated. The results indicate that the use of SHCC layers at the bottom of the slabs significantly increases the initial crack load, yield load and ultimate load, and the use of an expansive admixture in the SHCC material significantly affects the initial crack load of one-way slabs with an SHCC layer. Considerable reduction in the crack width and spacing was observed for slabs with an SHCC layer, and this tendency was particularly striking for slabs with an expansive and thick SHCC layer. It is concluded that the application of SHCC layers to RC members may prevent the penetration of aggressive substances into the concrete or reinforcement, and could greatly improve the durability of RC members.