关键词: 道路工程, 红粘土, 石灰, 承载比, 路基填料

Abstract: In order to promote the road construction in Yunnan red clay area and solve the problems of shrinkage cracking when red clay was used as roadbed filler, the lime-modified Yunnan red clay with the mass fraction of 0, 2%, 4%, 6%, 8%, 10% lime was studied. The liquid plastic limit test, compaction test, unconfined compression test, load ratio test and shrinkage test were used to evaluate the engineering properties of the modified red clay. The research results show that when the lime is added to Yunnan red clay for improvement, although the volume shrinkage, shrinkage coefficient and shrinkage limit of Yunnan red clay are slightly increased, the liquid limit, plasticity index and optimum moisture content of red clay are decreased a lot, and the shrinkage cracking of red clay is well restrained. The unconfined compressive strength and CBR of the lime-modified red clay are remarkably improved, and the deformation resistance is enhanced. Comprehensively considering the test results, adding 8% lime in Yunnan red clay can effectively improve the compaction characteristics of red clay, enhance soil strength, inhibit shrinkage cracking, and make it meet the technical requirements of highway subgrade filling.

Key words: highway engineering, red clay, lime, CBR, roadbed filler