成都地铁气密性混凝土配制及性能研究

Study on Preparation and Performance of Air Tight Concrete for Chengdu Metro

该文以成都轨道交通30号线一期工程为依托,为满足工程施工中气密性混凝土的需求,研究了水胶比、粉煤灰掺量、硅灰掺量以及砂率等配合比参数对混凝土气密性的影响,结果显示:随着混凝土水胶比的增大,混凝土透气系数急速上升,气密性能变差;随着混凝土中砂率的增大,混凝土透气系数降低,混凝土气密性提高。粉煤灰或者硅灰掺量的增加,可以提高混凝土气密性,尤其是硅灰的掺加,混凝土气密性提高更为显著。

In order to meet the needs of air tight concrete in Engineering construction,this paper,based on the phase I project of Chengdu rail transit line 30,studies the effects of parameters of mixing proportion such as water-binder ratio,fly ash dosage,silica fume dosage and sand ratio on air tightness of concrete.The results show that with the increase of water-binder ratio,the permeability coefficient of concrete increases rapidly and the air tightness gets worse;with the increase of sand ratio,the permeability coefficient of concrete decreases and the air tightness improves.The increase of the dosage of fly ash or silica fume can improve the air tightness of concrete,especially with the adding of silica fume.