Road Performance Of Polymer Modified Basic Magnesium Sulfate Cement For Concrete Pavement Repairing

After the great development of our country's economy,the main task of construction has been transferred to the facilities repairment,renovation and maintenance.The cement concrete pavement as one of the main road structure,the study on its repairment material will be a necessity for pavement repairment industrial future development and achievement of the sustainable development.The basic magnesium sulfate cement is a new type of ecological material,which has many advantages such as rich source of raw materials,extensive functions,renewable use,energy saving and excellent performance,etc.In this study,the basic magnesium sulfate cement-based material with better performance was prepared by adding the polymer emulsion.The main contents and conclusions are as follows:Firstly,considering the flowability,irrigation and the compressive strength at 7days in standard curing condition of indieator,the theoretical optimum dosage of the raw materials of basic magnesium sulfate cement and polymer type were determined by through orthogonal experiment.Based on the above experiment results,the initial proportion of the polymer modified basic magnesium sulfate cement material for repairing of pavement cracks was optimized.Secondly,the work performance,mechanical properties,shrinkage properties,adhesive properties and corrosion resistance of the basic magnesium sulfate cementbased repair materials with selected mix ratio were studied comprehensively and systematically.The influence of different polymer content,molar ratio of Mg O: Mg SO4:H2O and curing age on the properties of the composites were compared and analyzed.The results show that incorporation of polymers improved the viscosity of magnesium sulfate cement and showing a good mobility to meet the road surface crack repair process.Meanwhile the polymer also improved the toughness,shrinkage,corrosion resistance of cement and adhesion to old cement concrete pavements.Finally,a representative polymer modified magnesium sulfate cement sample was selected for microstructure analysis.The mechanism of polymer improved the road performance of basic magnesium sulfate cement-based materials was proposed.