混凝土微观结构与其抗冻融能力的关系研究

Study on relationship between microstructure of concrete and its ability to freezing-thawing resistance

按一定强度制作四组混凝土试件,一组不掺粉煤灰和引气剂,一组单掺粉煤灰,一组单掺引气剂,另一组双掺粉煤灰和引气剂,然后测定各组试件的抗冻融性能指标和内部孔结构。试验结果表明,双掺粉煤灰和适量引气剂,可以改善混凝土内部的孔结构,使孔径在50 nm以下的孔所占比例明显提高,100~200 nm范围内的有害孔大大减少,从而使混凝土的抗冻融能力显著增强。

Four groups of concrete specimens were produced according to certain intensity level, a group without fly ash and air - en- training agents, a group only with fly ash, a group only with air - entraining agents, another group with fly ash and air - entraining agents, then anti - freezing - thawin performance indicators and internal pore structure of the specimens were determined. The results show that mixing fly ash and air - entraining agents can improve the internal pore structure of concrete,increasing significantly the pro- portion of the pores with the diameter less than 50 nm,while greatly reducing the harmful pores with the diameter range 100 to 200 nm, so that the anti - freezing - thawing performance of concrete is significantly strengthened.