低气压环境对混凝土含气量及气泡稳定性的影响
发布时间：2018-09-19 16:10
【摘要】：通过低气压试验箱模拟高原不同海拔地区气压环境,研究了低气压环境对引气混凝土含气量及气泡稳定性的影响。结果表明:环境气压的降低能够显著削弱引气剂的引气能力,混凝土含气量随环境气压降低呈线性减少,当环境气压降低至50 k Pa时,混凝土含气量比常压环境下降低约28%~52%。低气压环境使引气混凝土气泡稳定性变差,在搅拌结束50~55 min内,低压引气混凝土含气量经时损失较大,且气泡间距系数明显增大;延长振捣时间会使低压引气混凝土损失更多气泡,从而导致含气量降低幅度以及间距系数的增大程度均大于常压引气混凝土。
[Abstract]:The influence of low pressure environment on the air content and bubble stability of air-entrained concrete was studied by simulating the atmospheric pressure environment in different altitude areas of the plateau by means of a low pressure test box. The results show that the air content of concrete decreases linearly with the decrease of ambient pressure. When the ambient pressure is reduced to 50 k Pa, the air content of concrete decreases about 28% and 52% than that under normal pressure. In the low pressure environment, the bubble stability of the air-entrained concrete becomes worse. Within 50 ~ 55 min after stirring, the air content of the low-pressure air-entrained concrete is larger and the bubble spacing coefficient is obviously increased. Prolonging the vibrating time will lead to the loss of more bubbles in low-pressure air-entrainment concrete, which will result in the decrease of air content and the increase of the spacing coefficient of air-entrainment concrete, which is larger than that of atmospheric air-entrained concrete.
【作者单位】： 交通运输部公路科学研究院;东南大学交通学院;
【基金】：国家自然科学基金(51308246)资助项目 交通运输部科技(201231879210)资助项目
【分类号】：TU528
[Abstract]:The influence of low pressure environment on the air content and bubble stability of air-entrained concrete was studied by simulating the atmospheric pressure environment in different altitude areas of the plateau by means of a low pressure test box. The results show that the air content of concrete decreases linearly with the decrease of ambient pressure. When the ambient pressure is reduced to 50 k Pa, the air content of concrete decreases about 28% and 52% than that under normal pressure. In the low pressure environment, the bubble stability of the air-entrained concrete becomes worse. Within 50 ~ 55 min after stirring, the air content of the low-pressure air-entrained concrete is larger and the bubble spacing coefficient is obviously increased. Prolonging the vibrating time will lead to the loss of more bubbles in low-pressure air-entrainment concrete, which will result in the decrease of air content and the increase of the spacing coefficient of air-entrainment concrete, which is larger than that of atmospheric air-entrained concrete.
【作者单位】： 交通运输部公路科学研究院;东南大学交通学院;
【基金】：国家自然科学基金(51308246)资助项目 交通运输部科技(201231879210)资助项目
【分类号】：TU528
【参考文献】
相关期刊论文 前5条
1 朱长华,谢永江,张勇,贾耀东;环境气压对混凝土含气量的影响[J];混凝土;2004年04期
2 杨钱荣;朱蓓蓉;杨全兵;王波;舒t，
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