Development of High Performance Concrete in a Ice Sea Environment.

为了开发石油资源和保护渔业，在近海和海冰环境中使用混凝土结构的需求增加了。这些环境对混凝土来说是严峻的，因为混凝土会受到霜冻、盐害和低温的物理性质。本报告研究了在海冰环境中使用的高性能混凝土。首先，通过水灰比和硅灰、矿渣、粉煤灰等外加剂的掺入，尝试提高混凝土的抗冻损性能。其次，提出了控制和保护钢筋混凝土腐蚀的新指标，并根据混凝土覆盖量的要求确定了钢筋抗腐蚀损伤的许用应力。第三，通过夏比冲击试验和跌落试验进行了低温下的冲击强度测试。研究了低温下的脆性行为，发现通过控制水灰比，低温下的冲击强度与常温相差不大，应力在低温下的传播速度比常温下快。

The demand for concrete structure using in a offshore and ice sea environment has increased to develop the oil resources and to conserve the fishery. These environments are severe for concrete due to frost damage, salt damage and physical properties of low temperature. This report investigates the high performance concrete using in a ice sea environment. The first, the attempts to improve the resistance of frost damage were performed by water-cement ratio and admixtures such as silica fume, slag and fly ash. The second, a new index was suggested for controlling and protecting reinforced concrete from corrosion and the allowable stress for reinforcing bars to improve the resistance of corrosion damage was defined by the required amount of concrete cover. The third, impact strength under low temperature was carried out by Charpy impact test and dropping test. The brittle behaviour under low temperature was discussed and it is found that the impact strength of low temperature was a little difference in normal temperature by controlling water-cement ratio and stress propagation in low temperature was more rapid than in normal temperature.