水工黏土基胶凝材料力学性能试验

为研制水工用黏土基胶凝材料,以航道护岸黏性弃土为主要原料,以试件抗压强度、劈裂抗拉强度及水稳定性作为控制指标,进行了水泥、石膏、矿粉等无机结合料掺量对黏土基胶凝材料力学性能影响的试验研究,并采用扫描电子显微镜分析试件的微观结构。结果表明:在黏性弃土、水泥、矿粉、石膏及石灰掺量分别为65%、18%、10%、2%和5%时,可获得28 d抗压强度达25.6 MPa、浸水强度达24.1 MPa、劈裂抗拉强度达2.5 MPa的黏土基胶凝材料;在不同的水化龄期,黏土基胶凝材料均生成了C-S-H凝胶等水泥基胶凝物质,这些产物相互交织、紧密结合,有效提高了材料的力学性能;该黏土基胶凝材料强度高、水稳定性好,可满足水运工程应用要求。

Experimental study on mechanical properties of clay-based cementitious material used in hydraulic engineering

In order to develop a clay-based cementitious material used in hydraulic engineering, the waste clay from a waterway revetment was used as a raw material. The influence of different contents of inorganic binder, such as cement, gypsum, and slag, on the mechanical properties of the clay-based cementitious material was studied by testing the compressive strength, splitting tensile strength, and water stability of specimens. A scanning electron microscope(SEM)was used to analyze the microstructure of specimens. The results show that when the mixing proportions of the waste clay, cement, slag, gypsum, and lime are 65%, 18%, 10%, 2%, and 5%, respectively, the compressive strength, immersion strength, and splitting tensile strength of the clay-based cementitious material at 28 d reach 25.6 MPa, 24.1 MPa, and 2.5 MPa, respectively. SEM results show that cement-based cementitious materials, such as C-S-H, were observed at different hydration ages, and these products effectively improve the mechanical properties of the clay-based cementitious material. It is concluded that the clay-based cementitious material shows high strength and water stability, and it can be used in hydraulic engineering.