Abstract：To investigate the impact of fly ash replacement cement ratios on the strength and internal pore structure changes of manufactured sand high-strength concrete(MSC)and natural sand high-strength concrete(NSC), C80 high-strength concrete was designed with fly ash replacement cement ratios of 0, 10%, 15%, 20%, and 25%, respectively. Nuclear magnetic resonance(NMR)technology was used to analyze the evolution of concrete pores, and X-ray diffraction(XRD), diffe-rential thermal gravimetric analysis(DTA), as well as field emission scanning electron microscopy(SEM)technology were used to analyze the morphology and microstructure of hydration products in cementitious materials. The results show that the strength of MSC is higher than that of NSC at all ages, and the initial strength decreases with the increase of fly ash content. In the later stage, the strength of 10% fly ash concrete is the highest; 10% fly ash promotes the hydration process of cement and fills gel pores to reduce the generation of cracks, thus optimizing the internal structural pores of concrete and improves the overall compactness of concrete. Considering the influence of fine aggregate morphology parameters and fly ash substitution rate on concrete strength, a 28-day compressive strength prediction model for fly ash concrete was established based on the compressible stacking theory with good accuracy. The research can provide some reference for the high-quality application of fly ash high-strength concrete.
韩长君,周海龙*,陈岩,张雪鹏. 粉煤灰对高强混凝土力学性能及孔隙结构影响[J]. 排灌机械工程学报, 2024, 42(): 410-417.
HAN Changjun,ZHOU Hailong*,CHEN Yan,ZHANG Xuepeng. Effect of fly ash on mechanical properties and pore structure of high-strength concrete. Journal of Drainage and Irrigation Machinery Engin, 2024, 42(): 410-417.
