摘要
试验研究了再生黏土砖粗骨料取代率、骨料强化、搅拌工艺、粉煤灰和硅灰单掺与复掺对黏土砖再生粗骨料混凝土抗氯离子渗透性能的影响。结果表明,随着再生骨料替代率的增加,再生混凝土抗氯离子渗透性能降低,替代率为0,30%,50%,70%,100%时,6 h通电量分别为2 090,2 596,3 207,3 989,5 182 C,氯离子渗透等级由适中过渡到高;骨料强化处理和改善搅拌工艺能够提高再生混凝土抗氯离子渗透性能,再生骨料取代率在50%以下,经过二次包裹强化或者采用改良的搅拌工艺后,再生混凝土的抗氯离子渗透性能与普通混凝土已经接近;粉煤灰和硅灰单掺或复掺可以较大幅度改善再生混凝抗氯离子的渗透性能,硅灰效果优于粉煤灰,20%粉煤灰和10%硅灰复掺可以作为最佳掺量,6 h通电量为171 C,可以用来配置较高抗氯离子渗透性能的再生混凝土。试验结果为再生混凝土推广应用提供了有力依据。
The influences of coarse aggregate replacement rate, coarse aggregate strengthening treatment with improved mixing, fly ash, silica fume on the resistance to the chloride ion permeability into the recycled coarse aggregate concrete are studied in this paper. The experiment results indicate that the resistance to the chloride ions permeability must decrease with the increase of a recycled aggregate replacement rate. When there are the replacement rates of 0,30%, 50%, 70% and 100%, 6 h electric charges are respectively 2 090, 2 596, 3 207, 3 989 and 5 182 C, with the chloride ion permeability level moving from the moderate to the high. Reinforcing the process of the concrete aggregate and improving the mixing process can improve the resistance to chloride ion permeability of the recycled concrete. As the recycled aggregate replacement rate is below 50%, the resistance to chloride ion permeability of the recycled concrete is close to that of the ordinary concrete after strengthening with twice packages or by improved stirring process. Mixing fly ash or silica fume alone or mixing both at the same time can significantly improve permeability resistance to the chloride ion into the recycled concrete, and the silica fume is better than fly ash in this respect. 20% fly ash admixed with 10% silica fume can be regarded as the best dosage, 6 h electric charge is 171 C, and the high-perfommnce recycled concrete having higher permeability resistance to the chloride ion can be made up by this way. The experiment results would provide a strong basis for popularization and application of the recycled concrete in civil engineering.
出处
《水利水运工程学报》
CSCD
北大核心
2015年第3期108-113,共6页
Hydro-Science and Engineering
关键词
再生粗骨料混凝土
骨料强化
粉煤灰
硅灰
氯离子渗透性能
recycled concrete
coarse aggregate strengthening treatment
fly ash
silica fume
chlorideion permeability
