Experimental Study And Engineering Application Of Cement Lime Stabilized Red Earth Gravel Base Course

With the continuous development of the national economy,the sense of global responsibility of China is getting stronger and stronger,and the country is providing more and more assistances to third world countries.Especially for basis engineering construction in African countries,China's assistance intensity is great,and many Chinese construction enterprises are participating in the construction in Africa.Based on the rehabilitation of Kihangou-Dolisie road section and the asphalt paving engineering construction in Congo,the red clay gravel in Congo Basin and Guilin was taken as the research object to carry out study of the feasibility and construction techniques of red clay gravel used for pavement base paving.The main content and conclusions of the project study are as follows:1.Through the indoor soil tests of natural African red clay gravel and Guilin red clay gravel,the basic engineering properties of the two kinds of red clay gravel were obtained,and the feasibility of the two kinds of red clay gravel for road use was analyzed according to the pavement design specifications in China and relying on the requirements of engineering technology.2.Cement and lime were used as modifiers to produce stabilized red clay gravel samples with different adulterate amounts(2%,4%,6% and 8%)of cement and lime,and CBR test,unconfined compressive strength test,disintegration test,permeability test,dry shrinkage test,dry temperature cyclic test and modulus of resilience test on the stabilized red clay gravel were done successively.Besides,based on the specifications and relying on the requirements of engineering technical documents,the feasibility of stabilized red clay gravel used for pavement base was analyzed.The results showed that the water stability and anti-permeability of African stabilized red clay gravel are superior to those of Guilin stabilized red clay gravel,and the higher the adulterate amount of inorganic binder is,the more significant the effect will be.,African stabilized red clay gravel with 4% of cement content and 8% of lime content can meet the strength requirement of road usage,and Guilin stabilized red clay gravel with 6% of cement content can meet the requirement of road usage.3.Based on the theory of orthogonal test,the main influence factors of pavement design were permutated and combined.The designing schemes for support construction pavement structure,semi-rigid pavement structure and flexible pavement structure were used as the basic schemes,and BISAR3.0 was adopted to analyze the dynamic response of pavement when red clay gravel was used as the base or sub-base layer,the reasonable layer and thickness of stabilized red clay gravel as pavement structure layer were analyzed,and recommendations were made.4.Combined with the support construction,the construction techniques for stabilized red clay gravel used as sub-base layer were studied.Through the construction of the test section,the construction equipment and technology of stabilized red clay gravel sub-base were verified,and the construction key points and construction quality control of the sub-base were analyzed and summarized.