基于UFAC应力吸收层的抗反射裂缝性能评价  

Evaluation of anti-reflective crack resistance based on the UFAC stress-absorbing layer

作　　者：李智[1] 童竞 LI Zhi;TONG Jing(School of Civil Engineering&Transportation,South China University of Technology,Guangzhou 510641,Guangdong,China)

机构地区：[1]华南理工大学土木与交通学院,广东广州510641

出　　处：《河南理工大学学报（自然科学版）》2025年第1期185-192,共8页Journal of Henan Polytechnic University（Natural Science）

基　　金：国家自然科学基金资助项目(51378223);广东省交通运输厅科技项目(2014-02-003,2016-02-003)。

摘　　要：目的为了解决“白加黑”技术中的反射裂缝问题,针对目前常用的悬浮密实型高弹改性沥青混合料(super flexible asphalt concrete,SFAC)应力吸收层变形量较大、容易造成上部沥青加铺层不利于受力的缺陷,方法提出基于CAVF法和富沥青理念优化设计的骨架密实型UFAC应力吸收层。采用有限元ABAQUS数值模拟方法对“白加黑”路面结构进行受力分析,并通过加速加载试验、冲击韧性试验和劈裂试验对材料与结构的抗反射裂缝性能进行评价。结果重载条件下,UFAC应力吸收层和高弹改性沥青应力吸收层的竖向位移相差5.93×10^(-2)mm,沥青加铺层底部所受竖向压应力σy、最大主应力σ_(max)、最大剪应力τ_(12)分别降低24%,32.3%,27.7%。当路面存在严重脱空或常规脱空情况时,基于UFAC应力吸收层的路面结构比GAC加铺路面结构的抗疲劳开裂性能分别提升48%,36%。与传统的悬浮型砂粒式AC-5应力吸收层相比,UFAC-5应力吸收层的冲击韧性增加60.8%,劈裂抗拉强度提高16.8%。结论基于UFAC应力吸收层的沥青加铺技术,通过增大常规改性沥青膜厚保证必要的疲劳抗拉能力,并采用骨架密实型级配显著提高集料间的嵌挤能力和内摩阻力,减小层间结构变形,可有效减缓沥青加铺层反射裂缝的产生与发展。Objectives To address the issue of reflective cracking in“white and black”pavement technol-ogy,this paper proposes an optimized design for a skeleton-dense UFAC stress-absorbing layer.This de-sign,based on the CAVF method and the concept of rich asphalt,aims to overcome the shortcomings of the commonly used dense-graded super flexible asphalt concrete(SFAC)stress-absorbing layer,which tends to exhibit significant deformation and adversely affect the overlaid asphalt layer.Methods The finite element method using ABAQUS was employed to conduct a stress analysis of the“white and black”pave-ment structure.Additionally,the reflective cracking resistance of the materials and structure was evaluated through accelerated loading tests,impact toughness tests,and splitting tests.Results Under heavy load con-ditions,the vertical displacement difference between the UFAC stress-absorbing layer and the SFAC stress-absorbing layer is 5.93×10^(-2)mm.Consequently,the vertical compressive stress(σy),maximum principal stress(σ_(max)),and maximum shear stress(τ_(12))at the bottom of the asphalt overlay are reduced by 24%,32.3%,and 27.7%,respectively.In cases where the pavement has severe or typical voids,the fatigue crack resistance of the asphalt overlay structures based on the UFAC stress-absorbing layer is improved by 48%and 36%,respectively,compared to the GAC overlay pavement structures.Additionally,compared to the traditional dense-graded sand-asphalt AC-5 stress-absorbing layer,the skeleton-dense UFAC-5 stress-absorbing layer exhibits a 60.8%increase in impact toughness and a 16.8%improvement in splitting tensile strength.Conclusions The significant deformation characteristics of SFAC stress-absorbing layers can ad-versely affect the overlaid asphalt layer,leading to reflective cracking and premature pavement damage.The asphalt overlay technology based on the UFAC stress-absorbing layer addresses these issues by increasing the thickness of the conventional modified asphalt film to ensure the necessary fatigue tensi

关 键 词：应力吸收层 薄层富沥青混合料 骨架密实型 有限元数值模型 抗压变形 

分 类 号：U414[交通运输工程—道路与铁道工程]