The Design Of Mix Proportion And The Analysis Of Construction Technics Of Semi-rigid Base

This kind of low_liquid_limit silty soil scoured by the Yellow River has very low content of clay particles, its non_uniformity coefficient small,and the activeness of its coloid poor, which all make its characteristic of road engineering very special. In the light of its special property being not easy to gain strength, through mechanics researches on different methods to stabilize this kind of low_liquid_limit silty soil as subbase material, evaluated both technically and economically, we have got a cement lime stabilization plan to meet the index requirements for non_side_limit strength of compression of subbase of Class2 road stipulated in the Specification; By means of improving the workmanship, thickening the loose layer of soil,adding soil on covering weave fabric before compaction, such problems can be solved as very poor compaction, loose surface during compaction, roughness and unevenness, coats of layer and shear damages. In the light of changing climate in our city and the great influences of climate on the early formed strength of such low_liquid_limit soil, we set up the evaluation standard for the stabilized mixture on natural curing condition. By means of selecting reasonable aggregate gradation, using more sand than stone powder to reduce fine aggregates, optimizing the mix design of different materials in the lime_flyash_stone mixture, improving the compaction technology, creating constant moist condition for the formed lime_flyash_stone base course during curing, lengthening curing period and properly controlling the moisture content of the base course during sealing construction, the shrinkage and cracking at the early age and for long use of the half stiff lime_flyash_stone base course can be remarkably reduced and proper and timely repairs thereof can effectively prevent more damages after cracking so as to increase the durability of the pavement.