矿物掺合料对海工自密实高性能混凝土耐久性影响

Effect of mineral admixture on durability of high performance self-compacting concrete for marine structure

采用粉煤灰、矿渣粉、石灰石粉、硅灰等矿物掺合料,配制出海工自密实高性能混凝土,并重点开展了海工自密实高性能混凝土耐久性,包括抗氯盐侵蚀、碳化、抗冻性和电阻率。试验研究结果表明,6种海工自密实高性能混凝土具有较高的抗氯盐侵蚀性能、抗碳化、抗冻性,56 d的电通量小于1 000 C,90 d的扩散系数小于1.5×10-12m2/s,56 d的碳化深度不大于7.5 mm,56 d抗冻性达到400次循环,56 d电阻率大于50 kΩ·cm,表现出较高的耐久性和保护钢筋能力。

By using fly ash,slag powder,limestone powder,and silica fume,high performance self-compacting concrete for marine structure was mixed and the durability of high performance self-compacting concrete for marine structure was emphatically studied, such as resistance to chloride and carbonization and freeze-thaw, and resistivity.Experimental results showed that the resistance to chloride and carbonization, and resistivity for six kinds of high performance self-compacting concrete for marine structure was high, and charge passed of specimens received standard curing for 28 days was less than 1 000 C,and chloride penetration coefficient of specimens received standard curing for 90 days was less than 1.5x10-12 mZ/s, and carbonization depth of specimens received standard curing for 56 days was not more than 7.5 mm, and the freeze-thaw cycle of specimens received standard curing for 56 days reaches 400 times, and the resistivity of specimens received standard curing for 56 days was more than 50 50kΩ·cm.In a word,the durability of high performance self-compacting concrete for marine structure developed was high.