Bond characteristics between conventional concrete and six high-performance patching materials

Repair of damaged concrete structures with patching materials is required for a wide variety of bridge and building applications. Despite the capabilities of conventional patching materials in replacing the spalled concrete, they are often unable to restore the original structural capacity. This has motivated research investigations to develop high-performance patching materials that can help damaged concrete structures regain their strength and durability characteristics. Such characteristics, however, are not properly achieved without a satisfactory bond between the concrete substrate and the patching material applied. To investigate this critical aspect, six high-performance patching materials, i.e., proprietary and nonproprietary ultra-high performance concrete, polypropylene and alkali-resistant glass fiber-reinforced concrete, high-early strength concrete, and shrinkage-compensating cement concrete, were systematically investigated and compared in the current study. The conducted experiments included a holistic set of splitting tensile and slant shear tests performed on the samples prepared with various surface roughnesses. The experimental test results provided firsthand information about the bond characteristics between normal-strength concrete and six high-performance patching materials. With the determination of corresponding adhesion and friction coefficient factors, the outcome of this study facilitates the selection and use of high-performance patching materials, depending on the availability of materials and repair needs.