Testing the bond between repair materials and concrete substrate

The bond strength of repair materials to the concrete substrate was investigated. This investigation was aimed at studying the effect of cyclic and static loading on bond as well as the effect of various surface treatments on bond strength. The study was also aimed at investigating the suitability of the slant shear test for evaluating cementitious and cementitious modified materials and resinous materials. A modified modulus of rupture (MMOR) test was also investigated as an alternative bond test to the slant shear method. A range of surface roughnesses were studied in the slant shear and MMOR tests. The samples were subjected to both static and fatigue loading. The tests have demonstrated the suitability of the standard slant shear test method for use with cementitious materials. Both the slant shear and MMOR tests were shown to be sensitive measures of the effects of surface preparation on bond strength. The needle gun method of surface preparation must be considered to be suspect as it could promote damage to the substrate.