Study On The Application Of The Hard Sandstone In Pavement Base And Sub-base In The Highway From Guangyuan City To Ba Zhong City In Si Chuan Province

Hard sandstone is a relatively small strength, water absorption and porosity of the larger rock. In this paper, the hard sandstone nature,the hard sandstone aggregate nature,the hard sandstone cement stabilized crushed stone mixture nature and road performance,the overall efficiency of instead of using hard sandstone and limestone,and the construction technology are analysed and studied systematically. First,the nature of hard sandstone is tested,including the weathered extent,density,water absorption,porosity,the uniaxial compressive strength under the three states,sturdiness and frost resistance. According to the nature and lithology analysis,the hard sandstone is graded,advantage and disadvantage is discriminated,and the nature of hard sangstone is coMPared with the limestone nature. Secondly,on the basis of lithology analysis,and according to aggregate regulation,the hard sandstone aggregate is tested,including crushing value,abrasion value,sturdiness,crushing value after sturdiness. According to the requirements of regulation and the result of test,that the hard sandstone is usefulness or not is evaluated,and the key indicators of the hard sandstone are gained,which effect the hard sandstone aggregate nature,and the sandstone aggregate nature is coMPared with the limestone aggregate nature.Thirdly, four types of mixture structure feature are analysed,which include frame dense type, frame void type,suspension dense type,uniform dense type. According to the local climate conditions,the frame dense type is selected to as cement stabilized crushed stone mixture pavement base and sub-base. Through the test and study on the cement stabilized crushed stone mixture nature,including no lateral compressive strength, splitting strength, flexural tensile strength, compression rebound modulus, durability, shrinkage property,the hard sandstone cement stabilized crushed stone mixture nature is coMPared with the limestone cement stabilized crushed stone mixture nature. According to the requirements of regulation,the qualified hard sandstone cement stabilized crushed stone mixture is discriminated, the key indicators of the hard sandstone are gained,which is whether usefulness. Finally,according to actual,author analyses how much money is saved,through the hard sandstone insteading of limestone,and compiles the construction technology, and draw a conclusion, and proposes the hard sandstone key indicators of hard sandstone as the raw material in pavement base and sub-base.