Development of Self-leveling Mortar for repairing concrete surfaces

Abstract

This research aims to improve the properties of self-leveling mortar for repairing concrete surfaces with the ability to work well, high compressive strength, no shrinkage, and taking less time in concrete surface repairing. The ingredients include Portland cement type III, coarse sand, fine sand as well as bulk water reducing agent, Mighty MX-H, with 2% of cement content quantity, silica fume with 5% of cement content quantity, Denka CSA 20 Reducer with 8% of the cement content quantity and Mighty 150SA-5 accelerator with 2% of the cement content quantity. The results showed that the self-flow leveling mortar using the 1:1.33 ratio of cement to sand, the 1:1 ratio of coarse sand to fine sand, and the 0.36 ratio of water to cement, have the ability to work well with the initial flow and flow retention; 167 mm and 126 mm respectively. The compressive strength was 19.47, 32.7, 44.67, and 61.75 MPa at 8, 12, 24 hours, and 28 days respectively. The flexural strength was 5.5. MPa at 28 days. In the mortar bond strength test, the result was 0.8 MPa at 7 days. The ring test for measurement of Restrained Shrinkage of Concrete showed no cracks at 14 days. The simulated test of repairing concrete surface size 50x100x2 cubic centimeters resulted in no delamination and cracks.