研究了引气剂对硬化混凝土强度和气泡特征参数的影响规律。结果表明:适宜的含气量不会对混凝土的抗压强度产生较大影响,但却使气泡间隔系数大大降低,从而极大提高了其抗冻性能。引气剂品种对新拌混凝土含气量与硬化混凝土含气量的相关性、硬化混凝土气泡间隔系数会产生显著影响,仅通过测定新拌混凝土含气量来评价抗冻质量,可能会出现较大偏差。

Effect of Air-entraining Admixtures on the Structure and Properties of Hardened ConcreteZHANG Jin-xi1,GUO Ming-yang1,YANG Rong-jun2,ZHANG Li3 (1.Key Laboratory of Traffic Engineering,Beijing University of Technology,Beijing 100022,China;2.Beijing Municipal Road & Bridge Construction Holding(Group) Co,Ltd,Beijing 100022,China;3.Beijing Changqing Municipal Engineering Co,Ltd,Beijing 100081,China)To popularize the application of air-entraining agent(AEA) in road cement concrete of China,five types AEAs were selected to research the effects of AEA on compressive strength and air void characteristics of hardened concrete.The results showed that suitable air contents couldn't reduce the compressive strength of hardened concrete excessively,which made the concrete's spacing factor reduce obviously and significantly improve the frost resistance of concrete.The types of AEAs would make significant effect on the relevance between the air contents of freshly mixed concrete and hardened concrete.There were substantial differences in spacing factor among concretes that used different AEAs even through the mixed concrete which had the same air contents.The method to determine the frost resistance of hardened concrete only through the air content of fresh concrete maybe had a great deviation.concrete;air-entraining agent;compressive strength;air void;frost Resistance