Abstract

The concrete used for pavement repair must have a very high-early strength for opening to traffic, good anti-shrinkage and anti-cracking performance, and interfacial bond between old and new concrete surface, besides the basic pavement performance. High fluidity is also needed for simplifying repairing operation and for guaranteeing the repair quality. In a sense, high fluidity is conflict with super high-early strength. In this paper, focusing on the early flexural strength, interfacial bond, shrinkage and cracking performance, the preparing and testing of high-fluidity and super high-early strength concrete (HFESC) for pavement repair was investigated. The repair concrete material, which is prepared with rapid hardening sulphoaluminate cement, aminobenzene sulfonamide superplasticizer and RF admixture, has 3.5 MPa 5 h-flexural strength, 20 MPa 5 h-compressive strength and 200 mm slump value. The laboratory test and field pavement repairing results revealed that the concrete has high fluidity and good mechanics performance and durability, which can be used in rapid repair of concrete pavement.

Key words: Rapid repair, superplasticizer, compatibility, early-strength admixtures, interfacial bond strength.