内养护剂、膨胀剂、减缩剂对高强混凝土早期收缩的影响

Influence of super absorbent polymer,expansion agent and shrinkage reducing agent on early autogenous shrinkage of high-strength concrete

文章采用非接触式混凝土收缩变形测定仪研究了内养护剂、膨胀剂、减缩剂及内养护剂与膨胀剂双掺、内养护剂与减缩剂双掺、膨胀剂与减缩剂双掺对高强混凝土早期收缩性能的影响。研究结果表明:内养护剂、膨胀剂、减缩剂的掺入均能明显降低高强混凝土的早期收缩值;单掺条件下,减缩剂的效果最好;双掺条件下均能产生叠加效应,其中0.20%内养护剂与2%减缩剂、10%膨胀剂与2%减缩剂双掺减缩效果最好,48h早期收缩值分别降低了70%和76%,且内养护剂与膨胀剂、内养护剂与减缩剂双掺中内养护剂与膨胀剂、减缩剂之间存在一定的比例关系,不同的掺入比例对收缩有显著影响。

The effect of super absorbent polymer（SAP） ,expansion agent（EA） and shrinkage reducing agent（SRA） admixtures on the early autogenous shrinkage of high‐strength concrete（HSC） was stud‐ied by using the non‐contact automatic testing device .The experimental results show that SAP ,EA and SRA can all restrain the autogenous shrinkage of HSC .Under the condition of adding one admix‐ture ,the reducing autogenous result of adding SRA is the best .Under the condition of double adding , when the SRA content is 2% and the SAP content is 0 .20% ,the autogenous shrinkage of HSC at 48 h is reduced by 70% ,and w hen the SRA content is 2% and the EA content is 10% ,the autogenous shrinkage of HSC at 48 h is reduced by 76% .Furthermore ,there is a certain proportion among them w hich has significant impact on the shrinkage of HSC .