A study for practical use of the concrete using natural resources "Shirasu" as an aggregate

1.材料数据库从鹿儿岛县的37个地方收集了白松样品，研究了白松作为混凝土骨料的性能和特征，并根据结果编制了数据库和白松地图。试验方法通过白筋骨料的比重、吸水率和细度模量试验，提出了考虑白筋性能的新试验方法。根据实验室和施工现场的实验结果，对白苏混凝土进行了包括准备、配合比设计、搅拌、放置、养护和检验在内的“使用白苏骨料的混凝土设计和施工建议”。耐久性进行了白露混凝土的暴露试验，以检查其长期耐久性，特别是关于中和，氯离子渗透，硫酸盐抗性和ASR.5的反应性。在上述试验的基础上，实现了温泉环境下桥梁结构基础混凝土和预应力PC预制梁混凝土的实际试验。此外，还考察了自密实混凝土和粉煤灰硬化材料的特殊适用性。

1.Material DatabaseFor the Shirasu samples collected from 37 places in Kagoshima prefecture, properties and characteristics of Shirasu as an aggregate for concrete were investigated, and according to the results, a data base and a Shirasu-Map, were prepured.2.Test MethodsAs the tests of specific gravity, water absorption, and fineness modulus for shirasu aggretate, new test methods considering the propery of Shirasu were proposed.3.Construction"Recommendation for design and construction of concrete using Shirasu aggregate" including preparation, mixdesign, mixing, placing, curing, and inspection, for Shirasu concrete was specified, according to the experimental results, in both labratry and construction site.4.DurabilityExporsure tests of Shirasu conrete were performed, to examine its long term durability, especially concerning to neutralization, penetration of chloride ion, sulfate-resistance, and reactibity of ASR.5.Practical UseDepending on above examinations, some practical trials, such as concrete in the foundation of a bridge structure constructed in hot spring environment and concrete for precast PC girder,were realized. Addition to that, some special applicability, for such as self-compacting concrete and hardened coal-ash material, were examined.