避免延迟钙矾石膨胀型免蒸压管桩掺合料

摘要

Concrete products under the curing temperature over 70℃have the risk of expansion damage from delayed ettringite formation. In order to avoid such risk on non-autoclaved piles, C80 concrete were made by a new type of high strength admixture, and the curing temperature was kept at 70℃. With such admixture, the compressive strength and dura-bility of the concrete were improved. Microscopic analysis showed that such admixture can help cement to produce mas-sively fibrous玉type of C-S-H gel, which filled the pores inside of the concrete to improve the strength and durability.%养护温度大于70℃的混凝土制品有产生延迟钙矾石膨胀的风险。为避免免蒸压管桩也产生这种风险,利用新型高强掺合料拌合的混凝土,经70℃的蒸汽养护6h,试块能满足C80的强度要求。与不掺相比,新型高强掺合料的掺入能大幅提高混凝土的抗压强度和耐久性。微观分析表明,掺新型高强掺合料的混凝土内部生成了大量的纤维状玉型C- S- H,填充了内部孔隙,从而提高了混凝土的强度和耐久性。