基于FWD的水泥混凝土路面板底脱空检测技术研究

Research on Testing of Void Under Cement Concrete Pavement Slab Based on FWD

为了明确落锤式弯沉仪(FWD)检测水泥混凝土路面板底脱空的测试方法和判定标准,基于水泥混凝土路面板底脱空形成机理,对FWD检测水泥混凝土路面板底脱空的基本原理、测点布置要求、脱空判定方法及标准进行了研究分析,提出了在现场检测时应确保测点位置干净整洁并施加恒定荷载以及选择在板块上、下表面温差较小时段检测等要求。根据工程案例以及FWD检测结果验证可知,当水泥混凝土板块板边中点弯沉值与板中弯沉值的比值大于2或板角弯沉值与板中弯沉值的比值大于3时,应综合判定该水泥混凝土板块存在脱空病害。

In order to make clear the testing method and judging standard of testing the void under cement concrete pavement slab by falling weight deflectometer(FWD),based on the formation mechanism of the void of cement con-crete pavement slab bottom,the basic principle of the testing technology,testing point arrangement requirements,void judging method and standard of FWD are studied and analyzed in this paper.During the test by FWD on site,the testing point should be cleaned,a constant load applied and small temperature difference should be selected.According to the engineering application case and FWD verification test,when the deflection ratio of midpoint of edge and midpoint of the slab is greater than 2 or the deflection ratio of corner and midpoint of the slab is greater than 3,it should be judged comprehensively that there is void under cement concrete plate slab.