海水海砂高性能混凝土的制备及耐久性研究

Research on the Preparation and Durability of Brine Marine Sand High Performence Concrete

本试验使用广东某公司提供的水泥基胶凝材料,使用海水海砂并与钢纤维、聚羧酸减水剂混合搅拌成浆体,浇注24 h后拆模然后置于80 ℃、湿度95 %环境养护48 h,制备出海水海砂高性能混凝土。28 d抗压强度达到132.06 MPa、抗折强度13.51 MPa、轴心抗压强度127.64 MPa,且当钢纤维掺量增加20 %、40 %与60 %时,抗压强度分别提高了3.88 %、7.34 %与9.41 %,抗折强度分别提高了4.52 %、21.76 %与29.02 %,轴心抗压强度分别提高了2.83 %、6.64 %与9.39 %。抗冻级别达到F500,28 d碳化深度为0,氯离子扩散深度为3.10 mm,氯离子扩散系数为0.13×10-12 m2/s,4次腐蚀循环后钢筋锈蚀率为0.50 %,质量损失为0.009 %,5 %Na_2SO_4溶液中150次干湿循环抗压强度耐蚀系数为116.99 %,3.5 %NaCl+5 %Na_2SO_4溶液中150次干湿循环抗压强度耐蚀系数达到139.61 %。制备的海水海砂高性能海工混凝土具有氯离子固化率高、工作性能良好、耐久性较好,且成本较低、原材料就地获取、施工周期短,适合推广应用。

This experiment using gelled cement based material brine,marine sand and steel fiber,poly carboxylic acid water reducing agent to form a slurry,poured after 24 h and then dismantled 48 h under 80℃,95 % humidity environment maintenance,the brine marine sand high performence concrete is prepared.The 28 d compressive strength reached 132.06 MPa,the flexural strength 13.51 MPa and the axial compressive strength 127.64 MPa.Moreover,when the proportion of steel fiber increased by 20 %,40 % and 60 %,the compressive strength increased by 3.88 %,7.34 % and 9.41 %,the flexural strength increased by 4.52 %,21.76 % and 29.02 %,and the axial compressive strength increased by 2.83 %,6.64 % and 9.39 %,respectively.Antifreeze level reached F500,28 d carbonation depth of 0,the chloride ion diffusion depth of 3.10 mm,the chloride ion diffusion coefficient of 0.13×10-12 m2/s,after four cycle corrosion rebar corrosion rate was 0.50 %,the mass loss of 0.009 %,5 % Na2 SO4 solution 150 times of the dry-wet circulation compressive strength corrosion resistance coefficient was 116.99 %,3.5 %NaCl+5 %Na2 SO4 solution 150 times of the dry-wet circulation compressive strength corrosion resistant coefficient is 139.61 %.The brine marine sand high performence concrete prepared by seawater has high chloride solidification rate,good working performance,good durability,low cost,on-site acquisition of raw materials and short construction period,which is suitable for popularization and application.