Study On Composition Design And Performance Of Composite Modified Mortar Based On Thin Layer Repair Of Cement Pavement

Thin layer disease of cement pavement refers to an early common damage caused by the functional layer of concrete surface mortar,which not only affects the beautiful appearance of the road,but also causes deep structural damage of the pavement in the long-term development.At present,the development of thin layer repair materials for cement pavement mostly focuses on the direction of flexibility,impact resistance,durability and adhesion.Based on the investigation of polymer modified cement-based repair materials,this paper proposes The emulsified asphalt,epoxy emulsion and cement are combined with the composite modified repairing material which is toughened by the fiber to the whole system.A thin layer of cement pavement with high strength,flexibility and durability is developed through the form of mortar preparation.Repair material-composite modified repair mortar.In the research,the emulsified asphalt and epoxy-curing system materials were firstly selected according to the compatibility and adaptability test between raw materials;then,based on the ISO mortar ratio,the targets according to emulsified asphalt,epoxy and fiber were used.The modification effect is preferably in the range of raw material dosage;finally,in the range of the preferred amount of raw materials,the 28 D mechanical strength,the compression ratio and the bending bond strength of the mortar are used as evaluation indexes for orthogonal test,and the range analysis method is used.The matrix analysis score method was used to analyze the test results,and the design ratio of the composite modified repair materials was determined: the emulsified asphalt content was 2%,the epoxy content was 6%,and the fiber content was 0.1%.On the basis of the design ratio of composite modified repair materials,the mortar work performance and mechanical strength were used as the evaluation indexes,and the single factor test analysis was carried out by comparing the water-cement ratio,the limesand ratio,the water reducing agent dosage and the defoaming agent dosage.The design ratio of the composite modified mortar is determined: the emulsified asphalt content is 2%,the epoxy content is 6%,the fiber content is 0.1%,the water cement ratio is 0.45,the lime sand ratio is 1:2.5,the water reducing agent 1.2%,defoamer 0.1%;using the mixing sequence of emulsified asphalt and epoxy in the mortar mixing process as the classification standard,design two mixing processes,through the mechanical strength test analysis,preferably after the "emulsified asphalt" The mixing process of the epoxyincorporated composite modified repair mortar.Taking ordinary cement mortar,emulsified asphalt cement mortar and epoxy emulsified asphalt cement mortar as reference,the mechanical strength,flexibility,shrinkage resistance,impermeability,salt corrosion resistance and interlayer adhesion of composite modified mortar Performance was compared and analyzed.The results show that the mechanical strength of the composite modified mortar meets the requirements of thin layer repair of cement pavement,and its performance is better than the other three mortars;the incorporation of emulsified asphalt improves the toughness of the mortar and reduces the compression ratio of the mortar.The interlayer adhesion property of the mortar is improved;the incorporation of epoxy further improves the interlayer adhesion property of the mortar,and at the same time compensates for the reduction of the mechanical strength of the mortar by the incorporation of the emulsified asphalt;the incorporation of the fiber significantly improves the impact resistance of the mortar.The ability to further enhance the durability and bonding properties of the mortar.In the cement pavement renovation project of Jixian Toll Station in Hatong Expressway in Heilongjiang Province,the composite modified mortar has a good effect on the repair of thin layer of cement pavement,and its repair performance is verified.