Development of High Performance Concrete in a Ice Sea Environment.

为了开发石油资源和养护渔业，近海和冰海环境中使用的混凝土结构的需求有所增加。由于冻害、盐害和低温的物理特性，这些环境对混凝土来说是严峻的。本报告研究在冰海环境中使用的高性能混凝土。首先，通过水灰比和硅灰、矿渣、飞灰等外加剂来提高混凝土的抗冻性。其次，提出了钢筋混凝土防腐控制的新指标，并根据混凝土保护层的要求确定了提高钢筋抗腐蚀损伤能力的钢筋许用应力。第三，通过夏比冲击试验和跌落试验进行了低温冲击强度试验。对低温下的脆性行为进行了讨论，发现通过控制水灰比，低温下的冲击强度与常温下相差不大，且低温下的应力扩展比常温下更快。

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.