Zhao Jun, Wang Kang, Wang Shuaibin, Wang Zike, Yang Zhaohui, Shumuye Eskinder Desta, Gong Xinglong
School of Civil Engineering, Zhengzhou University, Zhengzhou 450001, China.
School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, China.
Polymers (Basel). 2021 May 2;13(9):1473. doi: 10.3390/polym13091473.
This paper presents results from experimental work on mechanical properties of geopolymer concrete, mortar and paste prepared using fly ash and blended slag. Compressive strength, splitting tensile strength and flexural strength tests were conducted on large sets of geopolymer and ordinary concrete, mortar and paste after exposure to elevated temperatures. From Thermogravimetric analyzer (TGA), X-ray diffraction (XRD), Scanning electron microscope (SEM) test results, the geopolymer exhibits excellent resistance to elevated temperature. Compressive strengths of C30, C40 and C50 geopolymer concrete, mortar and paste show incremental improvement then followed by a gradual reduction, and finally reach a relatively consistent value with an increase in exposure temperature. The higher slag content in the geopolymer reduces residual strength and the lower exposure temperature corresponding to peak residual strength. Resistance to elevated temperature of C40 geopolymer concrete, mortar and paste is better than that of ordinary concrete, mortar and paste at the same grade. XRD, TGA and SEM analysis suggests that the heat resistance of C-S-H produced using slag is lower than that of sulphoaluminate gel (quartz and mullite, etc.) produced using fly ash. This facilitates degradation of C30, C40 and C50 geopolymer after exposure to elevated temperatures.
本文介绍了使用粉煤灰和混合矿渣制备的地质聚合物混凝土、砂浆和浆体力学性能的试验研究结果。对大量地质聚合物和普通混凝土、砂浆及浆体在高温作用后进行了抗压强度、劈裂抗拉强度和抗折强度试验。根据热重分析仪（TGA）、X射线衍射（XRD）、扫描电子显微镜（SEM）试验结果，地质聚合物表现出优异的耐高温性能。C30、C40和C50地质聚合物混凝土、砂浆及浆体的抗压强度随着温度升高先呈递增趋势，随后逐渐降低，最终趋于相对稳定的值。地质聚合物中较高的矿渣含量会降低其残余强度，且对应峰值残余强度的温度较低。在相同等级下，C40地质聚合物混凝土、砂浆及浆体的耐高温性能优于普通混凝土、砂浆及浆体。XRD、TGA和SEM分析表明，矿渣生成的C-S-H耐热性低于粉煤灰生成的硫铝酸盐凝胶（石英和莫来石等），这促使C30、C40和C50地质聚合物在高温作用后发生劣化。
