Experimental Investigation of Bond-Slip Performance of Reinforcement in Two Green Concretes

Abstract

Application of green cement to replace ordinary portland cement (OPC) for concrete structures has become an active research interest. Using pull-out tests, this study explored the bond behavior of embedded rebar confined by concretes made with two kinds of no-cement binders: (1) a hydraulic binder consisting of a ternary mixture of ground granulated blast furnace slag, low calcium fly ash, and circulating fluidized bed combustion (CFBC) fly ash, which is known as slag-fly ash-CFBC (or SFC) binder; and (2) an alkali-activated slag (AAS) binder. The experimental results showed that, at equivalent grades of 28-day compressive strength, the bond strength of the embedded rebar confined by concrete made with the SFC binder ranked the best, followed by OPC binder in the second place, and the AAS binder in the third place. Analysis of bond quality showed the satisfactory compatibility between the reinforcing bars and the confined green concretes, highlighting their high potential for successful application to the practical construction of infrastructure.