Preparation and characterization of multi-component fire-resistant cement-based materials

Abstract

In order to improve the high temperature resistance of cement-based materials, a new type of refractory cement-based materials was studied in this paper. Through systematic research, the composition of multi-component cement-based materials was optimized. After high temperature treatment at 300, 550, 850, 1200 and 1300 °C, the macroscopic properties such as mass loss, water absorption and strength of composite materials were tested respectively, and the microscopic characteristics of the composites were analyzed by XRD, SEM and MIP. The results showed that with the increase of the content of potash feldspar (PF), quartz (QZ) and alumina powder (AP), the strength of the specimen decreased at room temperature, but the compressive strength tended to be stable after being treated at 300–550 °C; After high temperature treatment at 850 °C, the strength of the sample is minimum or even loses its strength; After 1300 °C high temperature treatment, the compressive strength was obviously improved compared with normal temperature, but shrinkage and cracking appeared. Microscopically, XRD showed that calcination at 1300 °C, gehlenite and anorthite were formed, which was an important factor for the strength not to decrease; MIP and SEM results showed that under the same temperature treatment, the smaller the porosity of the sample, the denser the surface, and the higher the strength. However, after the high temperature treatment at 1300 °C, the porosity of the sample increased, and the surface became looser, but the strength increased, which was closely related to the formation of new phases.