Selection of compaction effort and compacting plants for semi-rigid base course(subbase)

This article analyzes the effect of changing the compaction effort to the parameters such as the optimum water content,the maximum dry density,the shape of compact curve for semi-rigid materials,by increasing or decreasing the number of compacting and the mass of weight.The test results have shown that the maximum dry density would increases if compaction effort is larger,while the optimum water content would decrease.Not only the optimum water content can be decreased with increase of the maximum dry density if the compaction effort is changed by altering the weight,but also the compact curve tends to be gentle,with lowering in the sensitivity of dry density to water content.As a result,the coefficient of unsensitivity,η,increases,while the degree of difficulty in the construction decreases.Based on the test results,this paper puts forward the selection of parameters and the methods for controlling the quality of compaction during the construction of semi-rigid base course or subbase.