橡胶粉对混凝土在水和NaCl溶液中抗冻性的影响

Impact of rubber powder on frost resistance of concrete in water and NaCl solution

通过快冻试验研究了平均粒径为140μm的橡胶粉对不同水胶比混凝土分别在水中和NaCl溶液中的抗冻性.研究表明,橡胶粉体积掺量为2%～4%时,其在混凝土中的颗粒中心距为330～660μm,高于引气混凝土建议的气泡间距20～200μm,而橡胶粉对混凝土抗压强度及抗冻性的影响效果与引气剂相当.橡胶粉掺量在合适的范围内可大幅度提高混凝土在水中和NaCl溶液中的抗冻性,但在NaCl溶液中的抗冻性较在水中差.

The performance of rubber included concrete under freeze-thaw cycling attack in both water and NaCl solution is investigated by fast freeze-thaw experiment. It is revealed that while the volume percentage of rubber powder varies between 2% to 4% , the particle space of 140μm diameter rubber particles ranges from 330 to 660μm, which is higher than the suggested void space of 20 to 200μm in case of air-entrained concrete. However, the compressive strength and frost resistance of such rubber included concrete are comparable to that of air-entrained concrete. Within suitable dosage, rubber powder can enhance the frost resistance of concrete in both water and NaCl solution, but the frost resistance in NaCl solution is not as good as in water.