Process for repairing concrete structures using pneumatically sprayable cement mortar compositions containing portland cement, mineral aggregate, a styrene-butadiene copolymer latex and water

In the process of repairing concrete structures by applying a cement mortar thereto the improvement consisting of pneumatically applying to the concrete structure to be repaired, a mixture of a substantially non-air entraining portland cement, mineral aggregate, a styrene-butadiene copolymer latex having a styrene to butadiene weight ratio of from about 30:70 to about 70:30, said copolymer being present on a solids basis in an amount of from about 5 to about 25 percent by weight of cement, and from about 0.1 to 5 percent of a polyorganosiloxane foam depressant based on the weight of active polyorganosiloxane, while maintaining the ratio of total water to cement in such mixture at a value of from 0.22 to 0.26.