摘要
本文将不同掺量的超细粉煤灰制备成活性粉末混凝土(RPC),测试新拌RPC浆体的扩展度,并研究不同养护温度(0℃,20℃和60℃)下RPC分别养护3 d、28 d和90 d后抗折强度和抗压强度以及RPC于20℃和60℃环境下养护24 d后浸泡在3.0%的NaCl溶液4 d后的冻融循环性能。研究结果表明:粉煤灰对硅灰的替代率越高,新拌RPC浆体的流动性越大;当RPC的配合比相同时,RPC的强度随着养护龄期和养护温度的增加而升高。当养护温度相同时,0℃或20℃温度环境下养护的RPC的强度随着粉煤灰替代率的增加而降低;然而,当养护温度恒定为60℃时,粉煤灰的掺入提高了RPC的强度。养护温度为20℃时,粉煤灰降低了RPC的抗冻性能,养护温度为60℃时,粉煤灰提高了RPC的抗冻性能。
In this paper, different amounts of ultrafine fly ash are prepared into reactive powder concrete(RPC),and the expansion degree of fresh RPC slurry is tested.The flexural strength and compressive strength of RPC at different curing temperatures(0 ℃,20 ℃ and 60 ℃) after curing for 3 d, 28 d and 90 d, respectively, and the freeze-thaw cycle performance of RPC after curing for 24 d at 20 ℃ and 60 ℃ and soaking in 3.0% NaCl solution for 4 d were investigated.The results show that the higher the substitution rate of fly ash to silica fume, the greater the fluidity of RPC slurry;when the mix ratio of RPC is the same, the strength of RPC increases with the increase of curing age and curing temperature.When the curing temperature is the same, the strength of RPC cured at 0 ℃ or 20 ℃ decreases with the increase of fly ash replacement rate.However, when the curing temperature is constant at 60 ℃,the incorporation of fly ash improves the strength of RPC.When the curing temperature is 20 ℃,fly ash reduces the freezing resistance of RPC,and when the curing temperature is 60 ℃,fly ash improves the freezing resistance of RPC.
作者
顾兴庆
张丽芳
高培伟
汪晖
GU Xingqing;ZHANG Lifang;GAO Peiwei;WANG Hui(College of Civil Aviation,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;School of Civil and Environmental Engineering,Ningbo University,Ningbo 315000,China)
出处
《粉煤灰综合利用》
CAS
2022年第4期54-59,共6页
Fly Ash Comprehensive Utilization
基金
2021年度浙江省自然科学基金(Y22E081344)。
关键词
超细粉煤灰
活性粉末混凝土
流动性
强度
NaCl冻融循环
superfine fly ash
reactive powder concrete
fluidity
mechanical strength
NaCl freeze-thaw cycles
