电厂炉底渣在全轻混凝土中的应用研究

Research on the Application of Power Plant Bottom Slag in Lightweight Concrete

摘要: 电厂炉底渣作为锅炉底部湿排出的灰渣，其含水高以及活性低的特点导致其难以被有效利用。为解决这一问题，本试验研究了炉底渣在全轻混凝土的制备中应用的可行性，分别研究炉渣砂和炉渣石等体积取代陶砂和陶粒对全轻混凝土坍扩度、容重、抗压强度的影响，并采用SEM和EDS对全轻混凝土微观形貌进行了分析。结果表明：炉渣砂中含有一定量粉煤灰，取代陶砂时能发挥形貌效应和火山灰效应，炉渣级配和密度与陶粒接近，全取代时全轻混凝土性能能满足设计要求。炉渣石与本试验所用陶粒相差较大，取代陶粒时对全轻混凝土的容重和抗压强度不利，取代量不宜超过25%。从微观分析结果来看，炉底渣掺入混凝土，能发挥火山灰效应，对水化有利。

Abstract: Power plant bottom slag, as the wet ash discharged from the bottom of the boiler, is difficult to be effectively utilized due to its high moisture content and low reactivity. To solve this problem, this study investigated the feasibility of using bottom slag in the preparation of lightweight aggregate concrete. The effects of slag sand and slag stone on the workability, density, and compressive strength of lightweight aggregate concrete were studied by replacing them with ceramic sand and ceramic aggregate, and the microstructure of lightweight aggregate concrete was analyzed using SEM and EDS. The results showed that slag sand, which contains a certain amount of fly ash, can exhibit pozzolanic and volcanic ash effects when used as a replacement for ceramic sand. The gradation and density of slag sand are similar to those of ceramic aggregate. When fully substituted, the performance of light-weight aggregate concrete can meet the design requirements. However, slag stone differs significantly from the ceramic aggregate used in this study, and its replacement has a detrimental effect on the density and compressive strength of lightweight aggregate concrete, with the replacement rate not exceeding 25%. From the microscopic analysis, it can be seen that the addition of bottom slag to concrete can exhibit a volcanic ash effect, which is beneficial for hydration.