C100机制砂免压蒸管桩混凝土配制技术研究

Research on concrete preparation technology of C100 machine-made sand non-autoclaved pipe pile

为实现节能低碳的生产工艺,推广应用C100机制砂免压蒸管桩,采用由I级粉煤灰、超细粉煤灰、硅灰组成的管桩专用矿物掺合料和机制砂试配免压蒸管桩混凝土,研究了矿物掺合料掺量、胶凝材料总量、水胶比、静停时间、升温速率对管桩混凝土性能的影响。结果表明:通过优化配合比设计参数和蒸养制度配制出适用于开模人工布料方式的免压蒸管桩混凝土,离心成型后内壁质量较好,蒸养脱模、3 d、28 d抗压强度分别超过95 MPa、100 MPa、105 MPa,蒸养脱模、28 d氯离子迁移系数分别低于4×10^(-12)m^(2)/s、3×10^(-12)m^(2)/s。

In order to realize the production process of energy saving and low carbon,C100 machine-made sand non-autoclaved pipe pile are popularizing and applying.The special mineral admixtures for pipe pile mainly contains I fly ash,ultra-fine fly ash,silica fume and machine-made sand were used to test and mix the concrete for non-autoclaved pipe pile.The effects of the mineral admixtures,the total amount of cementitious materials,the water-cement ratio,the static stop time and the heating rate on the performance of the concrete for pipe piles were studied.The results show that the non-autoclaved pipe pile concrete suitable for manual distribution mode of mold opening was prepared by optimizing the mix design parameters and steam curing system,the quality of the inner wall after centrifugal molding is good.The compressive strength of steam curing demoulding,3 d and 28 d exceeds 95 MPa,100 MPa and 105 MPa respectively,and the chloride ion migration coefficient of steam curing demoulding and 28 d is lower than 4×10^(-12) m^(2)/s、3×10^(-12) m^(2)/s。