海砂超高性能混凝土试验

采用未淡化的海砂制备超高性能混凝土（UHPC）和普通混凝土,研究了不同氯离子含量的海砂对UHPC抗压强度、孔结构、快速氯离子渗透性以及内置钢筋耐久性的影响,并与普通混凝土进行分析比较。结果表明,海砂中的氯离子含量对UHPC抗压强度并不会产生较大的消极影响;海砂UHPC的临界孔半径约为2 nm,与海砂普通混凝土不同,孔隙率随海砂中氯含量的增加而增加;即使海砂氯离子含量高达0.636%,海砂UHPC的氯离子渗透性仍可忽略不计;海砂UHPC中钢筋在28 d后处于钝化状态并趋于稳定。

Experimental study on sea-sand ultra-high performance concrete

In this paper, ultra-high performance concrete(UHPC) and ordinary concrete are prepared using undesalted sea-sand. The impact of sea-sand with varying chloride ion levels on the compressive strength, pore structure and durability of steel embedded in UHPC is investigated and compared with that of conventional concrete. The results show that the chloride ion content in sea-sand does not significantly negatively affect the compressive strength of UHPC. The critical pore radius of UHPC made with sea-sand is approximately 2 nm. Different from sea sand concrete, the porosity of sea-sand UHPC increases with the increase of chlorine content in sea-sand. Even when the chloride ion content in the sea sand is as high as 0.636%, the chloride ion permeability of the sea-sand UHPC remains negligible. The reinforcement in sea-sand UHPC is in a passive state and tends to stabilize after 28 days.