中文摘要：

为研究夹层、裂缝、加载方式对旧水泥路面沥青加铺结构沥青层底受力的影响,制作无裂缝有夹层、有裂缝无夹层、有裂缝有夹层3种试件,采用反力架装置和千斤顶施加荷载,在沥青层底粘贴应变片,通过电阻应变仪和电脑自动记录沥青层底的受力.针对各种工况,绘制了沥青层底的应力与外加荷载关系曲线,拟合了相应的数学关系式,求出了一些关键的沥青层底拉应力.研究表明：外荷载小于0.8 MPa时沥青层底受力状态较好;无缝有夹层的罩面结构沥青层底拉应力最小,加载至1.4 MPa时,层底拉应力仍然低于容许应力;当施加1.4 MPa的荷载时,夹层能减小沥青层底应力40.54%,裂缝能增加沥青层底应力46.67%,偏载能增加沥青层底应力100%.因此,旧水泥路面沥青加铺罩面工程,需要填补既有裂缝、设置防裂夹层、避免偏向受力、车辆荷载最好控制在0.8 MPa以下,才能降低沥青层底拉应力,保证工程质量.

英文摘要：

To explore how the interlayer,cracks and loading mode affect on the stress at the bottom of asphalt concrete overlaying old cement pavement structure,three kinds of test specimen,including no cracks and interlayers ones,no cracks or interlayers ones,were made.The large counterforce device and jack were used to load.Also,the strain gages,connected to resistance strain gauge and computer,were stuck to the bottom of the asphalt overlay,through which the stresses will be automaticlly recorded.According to various operating conditions,the relation curves between the stress of asphalt layer bottom and the load were drawn.The formulas of corresponding mathematical relationship were also fitted,by which some critical tensile stresses of asphalt layer bottom were calculated.Research shows that the stress status at the bottom of asphalt concrete is better when the external load is less than 0.8 MPa.As for the structure with interlayer but not cracks,the tensile stress is minimal,which is still lower than the allowable stress when loaded to 1.4 MPa.At the same load,the interlayer decreases the stresses of asphalt layer bottom 40.54%,and the crack or partial load increases stress of asphalt layer bottom 46.67% or100%.As a result,the engineering of asphalt concrete covering the surface of old cement pavement,needs to fill in the existing cracks,to set the anti-cracking interlayer,to avoid partial force,and to control vehicle load under 0.8MPa.Then,the tensile stress of asphalt layer bottom will be reduced and the engineering quality will be ensured.