不同孔隙率下沥青混凝土的水稳定性试验研究

摘要

沥青混凝土水稳定性损坏是由于水分进入其内部造成骨料与沥青胶浆剥离而产生的.为研究采用天然砾石骨料的水工沥青混凝土在不同孔隙率条件下的水稳定性能变化规律,在相同试验条件下,通过改变击实次数得到不同孔隙率的沥青混凝土试件进行浸水马歇尔试验和不同冻融次数的冻融劈裂试验.试验结果表明:在不同孔隙率条件下,沥青混凝土浸水残留稳定度随着孔隙率的增加而减小,但均满足规范要求;冻融劈裂强度随孔隙率的变化不明显,随着冻融次数的增加其强度略有降低;孔隙率对沥青混凝土的水稳定性影响程度低于填料类型和冻融次数;水泥填料的沥青混凝土冻融劈裂强度比石粉填料时大.%The water stability damage of asphalt concrete is due to water entering into the inside and causes aggregate and asphalt mortar peeling.In order to study the water stability performance of hydraulic asphalt concrete with natural gravel aggregate under the conditions of different porosity,the asphalt concrete specimens with different porosity are prepared by changing the hit times to carry out immersion Marshall test and freeze-thawing splitting test with different freeze-thawing times under same experimental conditions.The test results show that:(a) under the conditions of different porosity,the immersion residual stability of asphalt concrete decreases with the increase of porosity,but shall meet standard requirements;(b) the freeze-thaw splitting strength is not obviously changed with the change of porosity,and its strength will slightly decrease with the increase of freeze-thaw cycles;(c) the impact degree of porosity on water stability of asphalt concrete is lower than the filler type and the number of freeze-thaw cycles;and (d) the freeze-thaw splitting strength of asphalt concrete with stone powder filler is lower than that with cement filler.