超大尺寸地连墙混凝土在跨海通道中的应用研究

Research and Application of Large-scale Diaphragm Wall Concrete in Sea-crossing Passage

本文运用正交试验方法,利用双掺矿粉、粉煤灰及高性能减缩型减水剂配制C40高抗渗、低收缩海工混凝土,并对混凝土的工作性能、力学性能、渗透性能、收缩性能和微观结构进行系统研究,优化得到狮子洋通道西锚碇工程地连墙混凝土的最优配合比。结果表明:当粉煤灰掺量为30%、矿粉掺量为20%时制备的混凝土综合性能最优,混凝土的施工和易性及抗渗能力均显著提高。经过试验验证,制备的混凝土的7 d抗渗压力可达到1.4 MPa,28 d抗渗等级为P20,渗水高度小于20 mm,28 d氯离子扩散系数D RCM为2.2×10^(-12)m^(2)/s,60 d干缩值为112με,混凝土的体积稳定性提高,具有优良的抗裂防渗性。

This paper uses the orthogonal experimental method to prepare C40 high impermeability and low shrinkage marine concrete using double mixed mineral powder,fly ash,and high-performance shrinkage reducing water reducing agent.The working performance,mechanical performance,permeability performance,shrinkage performance,and microstructure of the concrete are systematically studied,and the optimal mix proportion of the diaphragm wall concrete for the Shiziyang channel west anchorage project is optimized.The results show that the comprehensive performance of concrete prepared with a mix ratio of 30%fly ash and 20%mineral powder is optimal,the construction workability and impermeability of concrete have significantly improved.After experimental verification,the 7 days impermeability pressure of the prepared concrete can reach 1.4 MPa,the 28 days impermeability grade is P20,the water seepage height is less than 20 mm,the 28 days chloride ion diffusion coefficient DRCM is 2.2×10^(-12) m^(2)/s,and the 60 days dry shrinkage value is 112με,the volume stability of concrete is improved,and it has excellent crack resistance and anti-seepage properties.