Application Of Geopolymer Grouting Method In Rapid Treatment Of Pavement Base Discontinuous Disease

With the rapid development of urbanization in China,the quality requirements of road engineering are also constantly improved.Early road base is easy to appear void and other damage diseases,the bearing capacity of the pavement is greatly reduced,and the demand for maintenance and repair is also showing a surge trend.However,the traditional excavation and reinforcement technology to deal with the disease of the base course has a long period,high cost and great impact on traffic.The grouting reinforcement technology takes advantage of the advantages of "no excavation" and rapid opening of traffic,avoids the excavation of the road,affects the pavement structure,and greatly reduces the impact of road repair on traffic.However,the existing grouting materials have the disadvantages of low early strength and large shrinkage,so it is urgent to develop new grouting materials for road subgrade reinforcement.This study intends to develop early strength geopolymer grouting material,which can be used to repair the diseases of urban pavement and subgradeFirstly,slag,fly ash and metakaolin are used as the main raw materials of geopolymer grouting materials,and sodium hydroxide and sodium hydroxide are used as alkali activators of geopolymer.The modulus(1.4,1.6 and 1.8),alkali content(6%and 8%),water cement ratio(0.28,0.30 and 0.32)and mixing time(3min,5min,10min)of geopolymer grouting material are studied The impact of.The results show that when the modulus is 1.6,the alkali content is 8%,the water cement ratio is 0.32,and the mixing time is 3 min,the geopolymer grouting material has good performance of setting time,fluidity,bleeding rate and compressive strength,which can meet the construction requirements.Secondly,the paper introduces the technological process of geopolymer grouting technology,and analyzes the construction points and technical requirements of drilling process and grouting process.Through theoretical calculation and field test,taking Guozhan road in Yangzhou City as an example,the key construction parameters of subgrade grouting reinforcement,such as grouting pressure and hole spacing,are determined.The grouting pressure is 0.6MPa,the grouting depth is about 80?120cm,the grouting amount is 70?120kg/M?2,and the hole distance is 150cm.Then,relying on the maintenance and reconstruction project of Yangzhou Guozhan Road,the practical application effect of geopolymer grouting reinforcement technology is studied.Based on the investigation results of the disease in the reconstructed road section,the grouting section and grouting construction scheme are determined;after grouting reinforcement,the dynamic deflectometer and test pit observation method are used to detect the reinforcement effect after grouting.The results show that the bearing capacity of pavement is significantly enhanced,the compressive strength and flexural strength are greatly improved after grouting with early strength and quick setting geopolymer,which is obviously higher than that of the existing pavement without disease.In addition,after 7 days of grouting reinforcement,the left and right wheel deflection values of asphalt pavement disease repair parts have further decreased,but they are basically the same as 1d deflection value,which shows that the early strength geopolymer grouting material developed in this study can effectively strengthen the road in a short time.Finally,the economic and social benefits of the reconstruction section are analyzed.The results show that compared with the traditional excavation treatment technology,geopolymer grouting reinforcement technology is used to reinforce the road surface,which has short traffic closure time and little traffic interference.It has good economic,environmental and social benefits,and has a wide application prospect.