红色石灰岩沥青混合料组成设计与应用

Composition Design and Application of Red Limestone Asphalt Mixture

为了研究细集料材质对红色石灰岩沥青混合料的AC-25,AC-20组成设计及性能的影响,选择密实型粗颗粒断级配,通过车辙试验检验其高温稳定性,采用多次冻融循环劈裂试验检验其水稳定性,利用不同温度下的黏聚力和内摩擦角评价其力学性能,并进行工程验证。结果表明:3.7%油石比下,相比石灰岩石屑,红色精品机制砂基质沥青混合料AC-25动稳定度相对提高了28.2%,冻融劈裂抗拉强度比相应更高;4.4%油石比下,相比黑色精品机制砂,红色精品机制砂SBS改性沥青混合料动稳定度相对提高了17.0%,冻融劈裂抗拉强度比也相应更高;不同温度下红色精品机制砂沥青混合料AC-25,AC-20黏聚力和内摩擦角试验结果相对增大;中、下面层红色精品机制砂沥青路面密实、抗变形能力强。红色石灰岩沥青混合料AC-25,AC-20应采用精品机制砂做细集料。

In order to study the influence of fine aggregate material on the composition design and performance of red limestone asphalt mixture AC-25 and AC-20,dense coarse grain broken grading is selected.Its high temperature stability is checked by rutting test,its water stability is checked by multiple freeze-thaw cycle splitting test,its mechanical performance is evaluated by using cohesion and internal friction angle under different temperatures,and engineering verification is carried out.The results show that the dynamic stability of AC-25 asphalt mixture with red fine machine-made sand matrix is increased by 28.2%,and the freeze-thaw splitting tensile strength ratio is higher than that of limestone chips at 3.7%asphalt aggregate ratio.At 4.4%oil stone ratio,compared with black fine machine-made sand,the dynamic stability of red fine machine-made sand SBS modified asphalt mixture is relatively improved by 17.0%,and the freeze-thaw splitting tensile strength ratio is also correspondingly higher.The test results of cohesion and internal friction angle of red fine machine-made sand asphalt mixture AC-25 and AC-20 at different temperatures are relatively increased.The middle and lower layers of red fine machine-made sand asphalt pavement are dense and have strong deformation resistance.The red limestone asphalt mixture AC-25 and AC-20 shall use high-quality machine-made sand as fine aggregate.