赤泥基超高性能混凝土的设计和性能研究

Design and performance study of red mud-basedultra-high performance concrete

为降低超高性能混凝土(Ultra-High Performance Concrete,UHPC)的能耗,探讨将赤泥作为矿物掺合料制备低碳超高性能混凝土(Low-Carbon Ultra-High Performance Concrete,LCUHPC)的可行性。基于颗粒紧密堆积理论,利用Modified Andreasen&Andersen模型设计了赤泥基UHPC,并对其工作性能、力学性能和耐久性能进行了系统表征。试验结果表明:赤泥的掺加降低了UHPC的工作性能、早期(7 d)抗压强度和耐久性。大掺量(30%)赤泥改性UHPC 28 d抗压强度大于100 MPa,电通量小于100 C,验证了赤泥制备LCUHPC的可行性。此外,有害组分浸出结果表明UHPC能有效固结赤泥中的重金属离子,有效降低了赤泥的高碱液浸出的风险。

In order to reduce the energy consumption of ultra-high performance concrete(UHPC),this study explores the feasibility of using red mud as the mineral admixture to replace cement and prepare a low-carbon ultra-high performance concrete(LCUHPC).Based on the theory of the closest packing of particles,the study designs a red mud-based UHPC by using the Modified Andreasen&Andersen model,and systematically characterizes its working performance,mechanical properties and durability.The test results show that the addition of red mud reduces the working performance,the early(7 d)compressive strength and the durability of UHPC.The 28 d compressive strength of UHPC modified by high volume(30%)red mud is greater than 100 MPa and the electric flux is less than 100 C,which verifies the feasibility of preparing LCUHPC with red mud.In addition,the leaching results of harmful components show that UHPC can effectively consolidate heavy metal ions in red mud and reduce the risk of high alkali leaching of red mud.