高温气候下沥青混凝土心墙连续碾压施工结合面温控试验研究

在夏季高温气候沥青混凝土心墙连续多层施工时,为减少等待结合面温度降至规范要求上限值90℃的时间,通过室内试验模拟结合面温度提高后心墙连续两层铺筑的情况,分别研究了结合面温度在90℃、100℃、110℃情况下沥青混凝土的压实性和变形情况,并进行了现场试验论证。室内试验结果表明:心墙沥青混凝土结合面温度降至100℃时,上层沥青混凝土的孔隙率为2.88%,下层沥青混凝土的最大侧向应变值为2.78%;结合面温度为110℃时,上层沥青混凝土的孔隙率为3.85%,下层沥青混凝土的最大侧向应变值为4.00%。现场试验结果表明:结合面温度为100℃时的上层沥青混凝土孔隙率和渗透系数均满足规范要求。因此,沥青混凝土心墙连续多层碾压时,结合面温度提高至100℃的施工质量可以得到保证。

Temperature control of joint surface of asphalt concrete core wall under the condition of continuous construction at high temperature climate

In situations of continuous multi-layer construction of the asphalt concrete core wall at high temperature climate of summer,it is required to wait for the joint surface temperature to reduce to the upper limit of 90℃according to the specification.In order to shorten the waiting time,indoor tests were conducted to simulate the scenario of paving two consecutive layers of the core wall with increased joint surface temperature.we studied the compaction and deformation of asphalt concrete with the joint surface temperature of 90℃,100℃and 110℃and verified the results with in-situ tests.The results showed that when the binding surface temperature of the core wall asphalt concrete reduced to 100℃,the porosity rate of the upper asphalt concrete was 2.88%,and the maximum lateral strain of the lower asphalt concrete was 2.78%.Whereas the porosity rate of the upper asphalt concrete was 3.85%and the maximum lateral strain of the lower asphalt concrete was 4.0%when the joint surface temperature was 110℃.The insitu field results indicate that the porosity rate and permeability coefficient of the upper asphalt concrete at the joint surface temperature of 100℃can meet the specification requirements.Therefore,when multilayers of the asphalt concrete core wall are being compacted continuously with increased joint surface temperature of 100℃,the construction quality can be guaranteed.