机场跑道改性沥青混凝土抗冲击性能

Impact Resistance of Modified Asphalt Concrete for Airport Runway

为研究中高应变率下NRP和掺高粘剂的SBS两种改性剂对AC-13型沥青混凝土动力性能的影响,采用直径74 mm SHPB装置进行了4个气压下的冲击压缩试验,获得了不同种类改性沥青混凝土的破坏形态及应力-应变曲线。研究表明:沥青混凝土动态应力-应变曲线分为弹性变形、塑性强化和塑性破坏3个阶段,破坏形态分为裂缝、破损、块裂和碎裂4种;两种改性剂均能改善沥青混凝土的抗冲击性能,并且对峰值应力和冲击韧性的应变率敏感性有一定影响,在不同应变率范围内两种改性剂对冲击韧性增强作用不同,NRP对峰值应力增强作用优于掺高粘剂的SBS;应变率超过130/s时,沥青混凝土出现弹性模量退化现象,NRP对弹性模量有提高作用。

In order to study the effect of two modifiers of NRP and SBS mixed with high viscosity agents on the dynamic performance of AC-13 asphalt concrete at medium and high strain rates,the paper used SHPB device to carry out impact compression tests.The failure modes and stress-strain curves of different modified asphalt concretes are obtained.Research shows that the dynamic stress-strain curve of asphalt concrete is divided into three stages:elastic deformation,plastic strengthening and plastic failure,and the failure modes are divided into four types:crack,damage,block crack and fragmentation;both modifiers can improve asphalt concrete.The impact resistance of NRP has a certain impact on the peak stress and strain rate sensitivity of impact toughness.In different strain rate ranges,the two modifiers have different impact toughness enhancement effects.NRP has better peak stress enhancement effect than doped high viscosity.When the strain rate exceeds 130/s,the elastic modulus of asphalt concrete will degenerate,and NRP can improve the elastic modulus.