水泥混凝土路面早龄期湿度场性状试验研究

Study on characteristics of cement concrete pavement internal moisture field at early-age

为了解水泥混凝土路面板早龄期湿度场性状特征,采用瑞士SHT15型数字化温湿度传感器,针对不同施工季节、不同基层与面板接触边界,进行水泥混凝土板早龄期湿度场的室外路面板监测试验研究.监测发现:水泥混凝土路面板湿度场在铺筑完之后依次经历饱和阶段、湿度下降阶段和波动阶段,各阶段的发生时刻和幅值取决周围气象条件和边界条件;通常工况下板底湿度高于板顶湿度,沿板厚方向形成湿度梯度,夏季施工路面早龄期板顶板底最大湿度差可达8%.此外,分析发现水泥混凝土路面相比其它混凝土结构,由于属于薄板结构,湿度场的影响和控制应额外注意混凝土路面基层边界条件与施工季节等因素.

In order to understand early-age moisture field of cement concrete pavement,using SHT15 type digital temperature and moisture sensors made in Swiss,site monitor test of early-age moisture in cement concrete pavements constructed in the different conditions were taken,considering the influence of different construction seasons and contact type between base and slab.Monitor results show that early-age moisture of cement concrete pavements has three stages after construction,successively including saturation stage,moisture decline stage and fluctuation stage.The times and amplitudes of three stages depend on meteorological condition and boundary conditions.Usually,moisture of concrete at the bottom of slab is higher than that on the top of slab,forming vertical moisture gradient along slab thickness.The moisture different between the top and the bottom of the slab constructed in summer is largest up to 8%.Besides,the results indicate that moisture field in cement concrete pavements is different from the moisture in other concrete structure,as cement concrete pavement is the type of thin-slab structure.Thus,it is recommended to pay more attention to the influence of concrete boundary condition between slab and base and construction condition,and to control these factors properly.