土工膜与沥青混凝土结构新型接头模型试验研究

Experimental Study on New Joint Model of Geomembrane and Asphalt Concrete Structure

为研究土工膜与沥青混凝土结构之间的接头连接方式,基于室内模型试验,从土工膜与沥青混凝土之间的粘结强度、接头适应变形能力、接头防渗性能3个方面论证土工膜与沥青混凝土面板接头的可靠性,提出了土工膜与沥青混凝土结构新型接头连接方式。结果表明:采用SK手刮聚脲将土工膜粘贴至沥青混凝土上,粘结的强度随环境温度降低而升高,5℃时,粘结强度可达到1.0 MPa;通过在接头部位设置鼓包,可以吸收接头变形;HDPE膜与沥青混凝土连接板的接头可以适应上下错动7.8 cm+张开5 cm+剪切7.2 cm的位移;施加变形后对接头进行抗渗试验,接头在0.45 MPa的水压力下可以保持防渗性能。采用SK手刮聚脲将土工膜与沥青混凝土直接粘结,采取合理的施工工艺可保证接头连接的可靠性和适应性,对推广土工膜防渗具有积极意义。

In order to study the reliability of joint connection between geomembrane and asphalt concrete structure,based on the indoor model test,the reliability of the joint between the geomembrane and the asphalt concrete panel is demonstrated from three aspects:the bond strength between the geomembrane and the asphalt concrete,the adaptability of the joint to deformation,and the impermeability of the joint,and a new joint connection between the geomembrane and the asphalt concrete structure is proposed.The results show that the strength of the bond increases with the decrease of ambient temperature,and the bond strength can reach 1.0 MPa at 5℃;the joint deformation can be absorbed by setting a bulge at the joint section,and the joint between the HDPE film and the asphalt concrete connecting plate can adapt to a displacement of 7.8 cm for settlement,5 cm for opening,and 7.2 cm for shearing.An impermeability test is conducted on the joint after deformation,indicating that the joint can maintain its impermeability performance under a water pressure of 0.45 MPa.The use of SK hand-scraped polyurea to directly bond the geomembrane with asphalt concrete,and the application of reasonable construction technology can ensure the reliability and adaptability of the joint connection,which is of positive significance for the promotion of geomembrane seepage prevention.