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1.前言建筑中使用的主要材料是钢材和混凝土。一般说来,混凝土的压缩强度很大,而抗拉强度或弯曲强度却很小。为此,在桥梁用的钢筋混凝土结构中,混凝土承受着压缩力,而抗拉力则由钢筋分担。为了充分利用混凝土的高压缩特性,通过钢筋预先将压缩力导入混凝土的预应力混凝土结构(PC)近年来非常盛行。这样的混凝土结构可说是半永久性的,可是若水份渗入混凝土的微细裂缝或混凝土使用含盐分的海砂时会使钢筋受到腐蚀而导致结构劣化。又有资料报道,在日本计划建设线性电动机牵引列车,如使用原来的钢材,会因磁化而带来功率损失,所以在某些特殊环境下使用原来的钢材和混凝土是不合适的。最近复合材料的发展非常迅速,其中纤维
1. Foreword The main materials used in construction are steel and concrete. In general, the compressive strength of concrete is great, but the tensile strength or bending strength is very small. To this end, in the bridge with the reinforced concrete structure, the concrete to withstand the compression force, while the tensile strength by the steel share. In order to make full use of the high compressive characteristics of concrete, prestressed concrete structures (PC) that pre-compress the compressive force into the concrete through steel tend to be very popular in recent years. Such a concrete structure can be said to be semi-permanent, but structural deterioration can be caused if the moisture infiltrates the fine cracks in the concrete or when the concrete uses sea salt containing salt. There are also data reported that in Japan plans to build linear motor traction trains, such as the use of the original steel, will cause power loss due to magnetization, so in some special circumstances the use of the original steel and concrete is not appropriate. The recent development of composites has been very rapid, with fibers