摘要
针对聚羧酸外加剂在管桩开模免蒸压生产中对混凝土和易性敏感,无法量化表征,混凝土操作性差,强度波动大等问题,利用不同聚羧酸母液及功能型助剂的复配技术,并掺加高性能活性粉HPAP,通过将开模混凝土的水胶比提高0.02后,测定倒坍时间、扩展度、含气量、抗压强度等指标,确定最佳外加剂配比。试验及试桩结果表明:该方法可以科学有效地评价低水胶比、半干硬性混凝土的和易性,试桩的脱模强度即可达到80 MPa以上,3 d强度最高达99.8 MPa,管桩内壁、外观均较佳。
In response to the sensitivity of polycarboxylate acid admixtures to concrete workability,inability to quantify characterization,poor workability of concrete,and large strength fluctuations in the production of pipe piles without steam pressure during mold opening,this paper uses a composite technology of different polycarboxylate mother liquors and functional additives,and adds high-performance active powder HPAP.By increasing the water cement ratio of 0.02 for mold opening concrete,indicators such as collapse time,expansion,gas content,and compressive strength are measured,determine the optimal admixture ratio.The test and piles testing results show that this method can scientifically and effectively evaluate the workability of low water cement ratio and semi dry hard concrete.The demoulding strength of the test piles can reach over 80 MPa,and the maximum 3 days strength can reach 99.8 MPa.The inner wall and appearance of the pipe piles are both good.
出处
《混凝土世界》
2024年第2期25-30,共6页
China Concrete
关键词
聚羧酸外加剂
管桩
免蒸压
和易性
评价方法
Polycarboxylic acid admixtures
pipe piles
non-autoclaved
workability
evaluation method
