U型膨胀剂掺量对自密实混凝土收缩性能影响

Influences of U-expansion agent on the shrinkage properties of self-compacting concrete

研究了膨胀剂掺量对低水胶比（W/B=0.28）自密实混凝土收缩性能的影响。结果表明：①自密实混凝土收缩率随着膨胀剂掺量增加而降低,其降低幅度随着龄期增加而降低,90 d以后趋于稳定;与未掺膨胀剂的自密实混凝土相比,掺膨胀剂的自密实混凝土收缩率7 d以内增加慢,在7~90 d内增加快;②自密实混凝土收缩落差随着膨胀剂掺量的增加先减小后增加,膨胀剂掺量10%自密实混凝土的收缩落差最小;③用对数函数表征自密实混凝土收缩率（d）与其龄期（t）的关系较为合适,回归曲线与实测值吻合较好。

Influences of expansion agent on shrinkage properties of low W/B ratio（W/B=0.28）self-compacting concrete were carried out.The results showed that the shrinkage of self-compacting concrete decreased with the increase of expansion agent dosage,the reduce value decrease with the increase of age,and become almost stable 90 d later.The shrinkage fall of self-compacting concrete decrease firstly and then increased with the increased of expansion agent dosage,The shrinkage fall of self-compacting concrete with 10% expansion agent was the smallest.The relationship which was expressed by the logarithmic function d=aln（t）＋b between the shrinkage of self-compacting concrete（d）with age（t）was more suitable,the regression curves agree well with experiment data.