粉煤灰再生混凝土氯离子渗透性能影响因素研究

通过对再生混凝土试件进行氯离子自然扩散试验,研究了粉煤灰掺量、干湿循环、侵蚀时间、孔隙率4个因素对再生混凝土氯离子渗透性能的影响。试验研究说明:外掺粉煤灰能够有效提高再生混凝土氯离子渗透性能,氯离子渗透能力随着粉煤灰掺量增加呈现先增强后减弱趋势,粉煤灰的最优掺量为20%;干湿循环条件可以显著加速氯离子的渗透性,干湿循环作用对氯离子渗透性的影响与是否掺加粉煤灰关系不大;氯离子扩散速率伴随着侵蚀时间的延长而明显增大,表层比内部扩散较快,侵蚀前60d扩散较慢,随后加快;氯离子渗透性能随着孔隙率变大而增强,粉煤灰掺量为20%时孔隙率最低,抗渗性最好。

Study on Influencing Factors of Chloride Ion Permeability of Fly Ash Recycled Concrete

The effects of fly ash content,wet and dry cycle,erosion time and porosity on the chloride ion permeability of recycled concrete were studied by using the chloride ion spontaneous diffusion test on recycled concrete specimens.The results show that the addition of fly asb can effectively improve the chloride ion permeability of recycled concrete,and the chloride ion permeation capacity increases with the increase of fly ash content,and then decreases with the increase of fly ash content.The optimum content of fly ash is 20％;The wet and dry cycle conditions can significantly accelerate the permeability of chloride ions.The effect of wet and dry cycle on chloride ion permeability is not related to the addition of fly ash.The diffusion rate of chloride ion is obviously increased with the prolongation of erosion time,The surface diffusion is faster than the internal diffusion,and the diffusion of the chloride ion permeability increases with the porosity increasing,and the porosity is the lowest when the fly ash content is 20％ and the impermeability is the best.