Research On Performance Improvement Technology Of Composite Stabilized Loess And Its Construction Evaluation Method

Composite stabilized loess can compensate for the shortcomings of stable materials such as lime or cement,and can also exert the performance advantages of soil curing agent.On this basis,it can save material costs,reduce stone mining and exhaust emissions.However,in the actual engineering application process,it is found that the soil curing agent has poor applicability to loess,lack of special material composition design methods and construction technology problems.These problems restrict the popularization and application of composite stable loess in road engineering.In view of this,based on the curing mechanism of soil curing agent and the engineering characteristics of loess,the modified lignin is used to improve the soil curing agent,and the soil hardener stabilized loess before and after the improvement is carried out by the unconfined compression test and the dry-wet cycle test.The microscopic mechanism was investigated by means of scanning electron microscopy(SEM).The relationship between the dose of curing agent and the plastic limit of composite stabilized loess was established.The composition of the composite stabilized loess was designed by liquid-plastic limit test and unconfined compression test.The performance of the composite stabilized loess after design was tested for strength,water stability and dry shrinkage.Finally,combined with laboratory test and test section laying,the construction technology and quality control technology of composite stabilized loess were studied.The results show that the modified lignin powder can be hydrolyzed and protonated with silty loess.The combination with soil curing agent can optimize the strength composition of loess,which can significantly improve the collapsibility of loess.The optimum dosage of soil curing agent in loess,the optimum dosage of lime/cement material is determined by 7d unconfined compressive strength.This method can shorten the test period,save material dosage and improve design accuracy compared with traditional orthogonal method.The composite stabilized loessspecimens prepared by the ratio described herein have high unconfined compressive strength and splitting strength,and the strength increases remarkably with the increase of curing time,water resistance and dry shrinkage performance,etc.Different degrees of improvement;from the test section laying results,the ionic conductivity can reflect the uniformity of the soil curing agent solution,when the conductivity remains stable,the curing agent solution can be considered uniform;borrowed modified Christianson uniform formula It can better evaluate the mixing uniformity of soil curing agent in composite stabilized loess.The research results in this paper can provide a useful reference for the composition design and practical application of composite stable loess materials.