Book Description

A wide variety of rapid set patching materials are available in the industry for repair of concrete. However, the selection of an appropriate material for a particular repair job is challenging as these materials possess a range of physical and mechanical properties and definitive criteria for establishing the compatibility between repair materials and substrate concrete are not adequately defined. Improper selection of repair material, without investigating the compatibility between repair materials and substrate concrete, is a common reason for failure. In this research study, compatibility between eight repair materials, that are on the approved list of the South Carolina Department of Transportation, and a typical substrate concrete was investigated in three stages. First, individual properties of the repair materials such as setting time, flow, compressive strength, flexural strength, split tensile strength, bond strength, drying shrinkage, freeze-thaw resistance, and permeability, were determined using standard ASTM test procedures. Second, the compatibility between repair material and substrate concrete was investigated by testing a composite beam (substrate concrete patched with repair material) in flexure under third point loading. Third, a correlation between the individual repair material properties and the performance of the composite beam was investigated to predict the compatibility of the concrete repair. Based on these studies, the compatibility of the repair materials was evaluated and a new test method is proposed to examine the compatibility between repair material and substrate concrete.