Flexural Strength of Cement Paste Beam under Chemical Degradation: Experiments and Simplified Modeling

Abstract

This paper presents the findings of a research program that developed prediction equations for estimating the flexural strength of degraded paste beams. Deterioration was attributable to calcium leaching from the beam’s four lateral sides. Given that natural leaching is a slow process, an accelerated experiment was performed by using a 6 M ammonium chloride solution. At specified leaching durations, sound and deteriorated beams were tested in flexure using the three-point bending (TPB) test. The leaching depth and the paste’s compressive strength were both measured. Based on the residual rate of compressive strength and the residual rate of the elastic modulus that was obtained from experimental data, the loss of flexural strength with respect to the leached ratio was constructed with a simplified model. The influence of the residual rate of tensile strength on the prediction and the best-fitting curves are presented. The degradation processes between flexural strength and compressive strength are different.