中性岩质机制砂对沥青砂浆力学性能的影响研究

为指导不同岩性机制砂在沥青路面的工程应用,选择3种岩质机制砂制备沥青砂浆试件,采用单轴压缩试验、冻融劈裂试验及浸水马歇尔试验检验其结构强度和水稳定性。结果表明：通过X射线衍射仪的矿物成分测试,所选的花岗岩、辉绿岩、石灰岩为典型的酸性岩、中性岩及碱性岩;相比石灰岩沥青砂浆抗压强度,花岗岩砂浆强度低2.5%,辉绿岩砂浆强度高约12%;从残留强度指标看,石灰岩砂浆冻融强度比最高,但从冻融前后的劈裂强度来看,辉绿岩砂浆的抗拉强度水平更高,3种机制砂的浸水马歇尔试验结果也呈现出一致的规律。与常规石灰岩机制砂相比,中性岩质辉绿岩机制砂兼具较好的材料强度与沥青黏附性,所制备的沥青砂浆抗压强度、水稳定性更好,具有良好的沥青路面工程应用价值。

Study on the Influence of Neutral Rock Manufactured Sand on Mechanical Properties of Asphalt Mortar

In order to study the effect of different lithological manufactured sands on the performance of asphalt mixture, three types of lithological manufactured sands were selected to prepare asphalt mortar specimens. Uniaxial compression test, freeze-thaw splitting test and immersion Marshall test were used to test the structural strength and water stability of asphalt mortar specimens. The results show that: through the mineral composition test of X-ray diffractometer, the selected granite, diabase and limestone are typical acidic rocks, neutral rocks and alkaline rocks. Compared with the compressive strength of limestone asphalt mortar, the strength of granite mortar is about 2.5% lower, the strength of diabase mortar is about 12% higher. From the residual strength index, the freeze-thaw strength ratio of limestone mortar is the highest, but from the perspective of splitting strength before and after freeze-thaw, the tensile strength level of diabase mortar is higher. The results of the water-immersed Marshall test of the three types of manufactured sand also show the same law. Compared with conventional limestone manufactured sand, neutral rock diabase manufactured sand has better material strength and asphalt adhesion. The prepared asphalt mortar has better compressive strength and water stability, and it has good asphalt pavement engineering application value.