半刚性基层沥青路面层间界面力学特性与黏结状态的试验研究

Experimental study on mechanical properties and bond condition at interlayer between asphalt surface and semi-rigid base

为了评价不同层间处理工艺的层间黏结效果及定量地评价重复荷载作用下的层间黏结状态,对试件做层间拉毛和洒布透层油处理,并与层间不做处理的试件进行对比.通过恒高度重复剪切试验分析了不同处理工艺、不同荷载作用次数下的层间界面力学响应规律,并采用层间黏结系数Ks作为层间黏结性能的评价指标.试验结果表明,相同荷载作用次数下,层间拉毛处理试件的层间剪应力和层间相对位移最小,剪切回弹模量最大,疲劳寿命为584次,层间黏结效果最好,但仍然处于半连续与半滑动状态;另外,对层间完全连续状态下的重复剪切试验进行了有限元模拟,得出了层间拉毛、洒布透层油、不做处理试件的层间黏结百分率分别为71.5%,54%,45%.

To evaluate interlayer bond effect through different treatments at interface between asphalt surface and semi-rigid base,and interlayer bond condition under repeated loading cycles,the roughening treated,untreated,emulsified asphalt treated specimen were compared. The repeated shear tests were conducted to analyze interlayer interface mechanical response under different numbers of loading cycles and bonding conditions. The interlayer bond coefficient Kswas selected as an evaluation index of interlayer bond properties. The experimental results showthat the interface shear stress and relative displacement are the smallest,and shear reaction modulus are the largest,and the fatigue life is 584 cycles for the roughening treated specimen,It is shown that the improvement on the interface bonding condition of roughening treatment is the best. However,even with the best treatment of roughening,the interface is still in the half bonding and sliding condition. In addition,the finite element simulation of the repeated shear test under the full bonding interlayer condition was conducted.It can be concluded that the bonding percentage for the roughening treated,untreated and emulsified asphalt treated specimen is 71. 5%,54%,and 45%,respectively.