Research On Rapid Repair Materials Of Cement Concrete Pavement

Cement concrete pavement is one of common pavements. It is widely used because of its high strength, durability, low cost. With the rapid development of China’s economy, the contradiction between road and vehicles becomes increasingly obvious, the quality and grade of road can not meet the current demand for vehicles, road congestion and damage can be seen everywhere in our country. Furthermore, cheating on workmanship and materials and trucks’overload make local area of the road have been out of all recognition when it does not meet the design life, and it causes travel inconvenience. Repair material of cement concrete pavement is divided into organic and inorganic repair materials by material category. Asphalt or epoxy is generally selected as the organic repair material, but this kind of repair materials has some shortage:poor compatibility with cement, high cost, different color with cement, and easy to aging. Inorganic repair materials mainly include cement material, but it brings a lot of problems due to condition defective of cement itself. It usually requires closing partial traffic when Portland cement used in repairing pavement. It costs at least24hours to open traffic, and which increases the load of roads. Secondly, the new concrete does not bond the original concrete, which causes local defect of bonding part. It results in damage of pavement just after its repairing soon.In this paper, alumina cement and sulphoaluminate cement, two different special cements, are mixed with ordinary Portland cement,5044emulsion powder and plaster are added in to adjust. Experiments mainly include:study on mix ratio of the amount of cement blending, study on setting time of cement, study on mechanical property test of cement mortar, study on mechanical property test of concrete and study on bond strength test of repair materials, etc.The mixing amount of special cement should be controlled below28%, and then its all aspects of performance could gradually meet the requirements of the performance of road repair materials. In this paper, the setting time of cement is also measured. The setting time of cement is delayed4-16min after plaster and emulsion powder are added into alumina cement. And it delays12-30min after added into sulphoaluminate cement. In this paper, the properties of cement mortar, which mixes amount of17%to28%special cement, are studied. The repair effect of repair mortar is best when the ratio of alumina cement is17%. And it is best when the ratio of sulphoaluminate cement is22%.In the paper, the mechanical properties of concrete of repair materials are studied. The same kind of mix proportion is used to mix concrete during the experiment. It is found that concrete contained alumina cement meets C25of strength grade of concrete for road, and concrete contained sulphoaluminate cement meets C30.Finally, the bonding strength of repair materials of cement concrete is studied in this paper. It is found that bonding strength of repaired materials contained alumina cement is about2.0～3.0MPa, and repaired materials contained sulphoaluminate cement is about2.5～3.5MPa.