Preliminary and experimental study of mortar development for cracked concrete repair with injection method

Crack in the concrete road has become a huge concern because it may cause cavities formation. The cavity formed could lead to an infiltration of rainwater into the soil at the base of the concrete, and make the soil wet and soft. This condition may produce cracks or gaps in the concrete road liquefied by the great pressure, especially when heavy-loaded vehicles cross the concrete road, thus making the cracks to be wider. These wider cracks cause the water to seep into the ground easily, and allowing the crack to expand in all directions. This may cause the road to be completely damaged. The purpose of this experimental study is to repair road concrete cracks and to reduce the effect of the liquefaction process by simulating the injection process of mortar, which could seep widely in the soil under the miniature concrete road and fill in the gaps formed by the liquefaction process. The composition of the mixture for the injection is primarily cement-based with a 0.44 water-cement ratio. Fine aggregate is sieved to be less than 2 mm in size, with an aggregate-cement ratio ranging from 0 to 3. Glass fiber is then used as reinforcement with a length of 50 mm and a ratio of glass fiber and cement between 0 and 0.012. Finally, the three-point bending, compressive strength and slump tests are conducted to determine the optimum composition ratio for the injection in the cracked concrete. The results show that the optimum ratio of aggregate-cement is 0.78.