Study On Performance Of The Material To Quickly Repair Cement Concrete Pavement

Since the Open-Door Policy,the economic construction of our country gained the success attract worldwide attention.But the development of economy is inseparable from transportation.Therefore,from the beginning of reform and opening up to the present,in order to promote the development of transportation,China has built a large number of highway projects.By the end of 2016,the total mileage of highways in our country had reached 4.69 million km,and the expressway reached 131000 km?However,due to the rapid growth of traffic volume,the damage of traffic facilities such as roads,bridges and tunnels is also becoming more and more serious,which has a great impact on the quality of driving and driving safety.In recent years,the annual demand for funds for highway maintenance and management has been more than 300 billion yuan,which makes considerable pressure to finance.This paper mainly studies the problems of local repair of cement concrete pavement,such as non penetrating cracks,spalling,seam broken plate angle and pits.The mending material is mainly composed of slag and a proper amount of alkaline activator.The research mainly uses fiber and anhydrite expansion agent to modify alkali slag cementitious material,and the effects on the working performance,mechanical properties and shrinkage properties of pavement repair materials are studied,and the microstructure and hydration products of the mending materials are analyzed by means of infrared spectroscopy and SEM.The results show that:Through an experimental study of the effects of water glass modulus,alkali content,water / cement ratio on the setting time and mechanical property of cement cement pavement repair materials,and the results show that the repair material prepared with1.4 modulus sodium silicate has the best mechanical property and the setting time is moderate,and the ratio of water to binder is 0.3,the ratio of cement to sand is 1.5.Through an experimental study of the effects of alum and gypsum on the fluidity,in combination with infrared analysis,it was found that after the addition of expansion agent,the formation of ettringite in the repaired mortar compensates the shrinkage of the repair mortar,and the mechanical property of the repair mortar will decrease in varying degrees.The strength of the repair mortar will decrease more when the content of gypsum is greater than 1%,and the strength of alum decreases more when the amount of alum is more than 6%.Through an experimental study of the effect of basalt fiber on the fluidity,mechanical property and shrinkage of alkali slag cementitious material,combined with SEM analysis,the results show,with the increase of basalt fiber content,the fluidity of the repair material decreases,the flexural strength and the compressive strength after 7days first increase and then decrease.when the content of 6mm basalt fiber is 0.15%,the mortar is the best to wrap the fiber,the mechanical property and shrinkage property of mortar were improved best.Through an experimental study of the effects of gypsum,alum and 6mm basalt fiber on the properties of repaired mortar,and combining the orthogonal analysis of thedata,it is found that multicomponent addition can further reduce the shrinkage of the material,and the fiber can also reduce the strength loss of the repair material.The early and late mechanical properties of the repair materials modified with 0.5% gypsum and0.15% basalt fiber are the best,and the shrinkage property basically meets the requirements of pavement repair materials for 28 days.After the conclusion,it is suggested that the mix proportion of quick repair materials is: the ratio of water to binder is 0.3,the alkali content is 11%,gypsum content is 0.5%,and 0.15% basalt fiber.