摘   要：基于预应力钢筒混凝土管（PCCP）外层防护水泥砂浆受拉易裂的问题及消纳大宗工业固废和降低水泥碳排放的目的，以赤泥、粉煤灰和矿渣全取代水泥，制备得到了满足低碳及拉伸变形需求的全固废基高延性地质聚合物复合材料（High Ductility Geopolymer Composites, HDGC）。通过改变前驱体相对含量，探究了HDGC的宏观和细观力学性能、微观形貌及应变硬化能力。结果表明：HDGC的抗压强度随赤泥掺量的增加而减小，随矿渣掺量的增加而增强，但抗拉强度与弯曲强度随矿渣掺量的增加先增大再减小；矿渣掺量为20%的HDGC抗压强度不低于45 MPa，抗拉强度与拉伸应变分别大于4 MPa和4%；HDGC细观力学参数均随矿渣掺量的增加而增大，其强度指数和能量指数高于推荐阈值，拉伸应变硬化能力显著。 Abstract: In addressing the issue of the cracking susceptibility of cement mortar in the outer layer of prestressed steel cylindrical concrete pipes (PCCP), and with the goal of utilizing bulk industrial solid waste and reducing cement carbon emissions, the High Ductility Geopolymer Composites (HDGC) based on solid waste was prepared by replacing cement with red mud, fly ash, and slag to meet the requirements of low-carbon and tensile deformation. The mechanical properties, microscopic morphology, and strain-hardening capacity of HDGC were investigated by varying the relative content of precursors. The results show that the compressive strength of HDGC decreases with the increase of red mud content and enhances with the increase of slag content, but the tensile strength and bending strength first increase and then decrease with the increase of slag content. The compressive strength of HDGC with 20% slag content exceeds 45 MPa, whose tensile strength and strains exceed 4 MPa and 4% respectively. The micro mechanical parameters of HDGC increase with the increase of slag content, and their strength index and energy index are higher than the recommended threshold, and the tensile strain hardening ability is significant.

杜智荣,侯宇,吕邦成,等.PCCP外层防护用复合材料的力学性能研究[J].混凝土与水泥制品,2024(6):43-50. DU Z R,HOU Y,LYU B C,et al.Research on mechanical properties of composite materials for PCCP outer layer protection[J].China Concrete and Cement Products,2024(6):43-50.

摘   要：针对地铁车站桁架钢筋混凝土叠合双向板的连接施工效率及可靠性问题，提出了采用附加U形钢筋（方案1）和底板钢筋弯折锚固（方案2）进行拼缝连接，并对两种方案连接的双向板开展了静力试验，得到了试件的裂缝开展过程、最终分布形态、承载力及变形数据。结果表明：两种连接方案均呈现出较好的双向板破坏形态，且均能满足正常使用极限状态及承载能力极限状态的设计要求；方案2较方案1，试件表现出更好的抗裂性能，但两者最终破坏时的承载力与挠度较为接近；两种方案均可满足双向板受力要求，且施工简便，可供同类工程参考。 Abstract: Aiming at the efficiency and reliability of the joint construction of two-way truss reinforced concrete laminated slabs in metro stations, the additional U-shaped rebars(scheme 1) and the bending anchorage of the bottom plate rebars(scheme 2) were proposed for the joint connection. The static load test was carried out on the two-way slabs with two schemes, the cracking distribution, the load carrying capacity and deformation data of the specimens were obtained. The results show that both the specimens of the two schemes show ideal damage patterns of two-way slabs, and both can meet the design requirements of normal service limit state and load capacity limit state. The specimen of scheme 2 shows better crack resistance than that of specimen using scheme 1, but the load capacity and deflection of the specimens of the two schemes are closer to each other in the final damage. Both the two schemes can meet the force requirements of two-way slabs, which can provide a reference for the similar projects.

莫振泽,李鹏,赵海川,等.地铁车站桁架钢筋混凝土叠合双向板的连接构造研究[J].混凝土与水泥制品,2024(6):51-54. MO Z Z,LI P,ZHAO H C,et al.Study on the connection construction of two-way truss reinforced concrete laminated slabs of metro station[J].China Concrete and Cement Products,2024(6):51-54.