Scaling resistance and application of cementitious repair mortars for concrete barriers

Liaoning Province is located in the northeast of China, where the concrete barriers along with highways and roads deteriorate severely due to deicer salt scaling. In this paper, cementitious mortars for repairing concrete barriers were investigated. After determining the dosage of copolymer powder, polyacrylonitrile fiber and sand-cement ratio by orthogonal tests, six cementitious mortars with or without air-entraining agent or silica fume were prepared and their strengh at 28 days and scaling resistance were investigated. Then two mortars were used for field application in Liaoning Province. The laboratory study results showed that the cementitious mortars with proper air content exhibited good scaling resistance and higher strength. Adding copolymer powder and polyacrylonitrile fiber also improved scaling resistance of the mortar. In spite of no obvious effect, silica fume improved scaling resistance of repair mortars when it worked with air-entraining agents. The two selected cementitious repair mortars generally performed well in the field application.