一种沥青混凝土中低温断裂性能统一评价方法  

A unified evaluation method for intermediate and low temperature fracture performance of asphalt concrete

作　　者：宋卫民[1] 徐子浩 吴昊[1] 徐飞 詹易群 SONG Weimin;XU Zihao;WU Hao;XU Fei;ZHAN Yiqun(School of Civil Engineering,Central South University,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075

出　　处：《中南大学学报（自然科学版）》2021年第7期2386-2393,共8页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(52008405,51778638);湖南省自然科学基金资助项目(2020JJ5744)。

摘　　要：为了采用统一的参数评价沥青混凝土在中低温条件下的断裂韧性,使用一种基于能量法的等效应力强度因子(K_(IC)^(*))来评价沥青混凝土在中低温条件下的抗断裂能力。采用开口半圆断裂试验(SCB)测试3种不同再生沥青骨料(RAP)掺量(0,25%和50%)的沥青混合料在-10℃的应力强度因子(KIC)和断裂能(G_(F))以及25℃积分的J积分和等效应力强度因子(K_(IC)^(*))。研究结果表明:-10℃时,掺质量分数为25%的RAP的沥青混凝土应力强度因子达到最大,但断裂能随着RAP掺量的增加逐渐降低;25℃时,随着RAP掺量增加,J积分显著增大,添加RAP可以在一定程度上提高沥青混凝土的中温断裂性能;25℃时,K_(IC)^(*)随着RAP掺量增加而逐渐增大,说明等效应力强度因子判据可以用于评价沥青混凝土的中温断裂韧性。To evaluate the fracture toughness of asphalt concrete at intermediate and low temperatures by a unified indicator,an equivalent stress intensity factor(K_(IC)^(*))based on energy approach was used to evaluate the fracture resistance of asphalt concrete at intermediate temperatures.Semi-circular bending(SCB)tests were conducted on specimens incorporated with three different contents of reclaimed asphalt pavement(RAP)(0,25%and 50%).The parameters of stress intensity factor(KIC)and fracture energy(G_(F))were measured at-10℃,and J integral and K_(IC)^(*) were measured at 25℃.The results show that the stress intensity factor of specimens with 25%RAP obtains the maximum value at-10℃,whereas,the fracture energy declines with the increase of RAP mass fraction.At 25℃,J integrals increase remarkably along with the RAP mass fraction inclusion,which indicates that RAP can enhance the fracture performance at the intermediate temperature.The equivalent stress intensity factor(K_(IC)^(*))also improves along with the increase of RAP mass fraction,which demonstrates that the equivalent stress intensity factor criterion can be used to evaluate the low-intermediate temperature fracture toughness of asphalt concrete.

关 键 词：中低温 断裂韧性 等效应力强度因子 断裂能 再生沥青骨料 

分 类 号：U414[交通运输工程—道路与铁道工程]