Self compacting grout and concrete: How it is produced and why it is needed

A lot of concrete dams and their ancillary buildings need to be repaired because of freezing and thawing, scour and erosion. For large area concrete repair, replacement of concrete is a good choice, especially when the depth of the repairing area exceeds 6 inches But this method has some disadvantages in some aspects, compared with the cement or polymer mortar. For example, the durability, interface bond strength, and the complicated repair procedure. In this study we developed a Polymer Modified Self Compacting Concrete (PMSCC) which can achieve self compaction without any vibration. Experimental results show that the tensile strength of the PMSCC is 3.63 MPa at 28 days, the ultimate tension strain is 179 microstrain increased by 54.3% compared with Portland cement self compacting concrete, and the relative dynamic modulus of elasticity is 97% after 300 times freezing and thawing circles Simulation test shows that the interfacial bond strength between new and old concrete is higher than 1.56 MPa without any adhesives In addition, finite element analysis results show that appropriate setting joints could effectively avoid thermal cracks during the operation stage. PMSCC has the features of “high anti-crack ability, good durability and high bond strength” which is suitable for the replacement of large area deterioration concrete, especially for the dam upstream concrete.