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

1.材料数据库以鹿儿岛县37个地点的白砂为研究对象，对白砂作为混凝土骨料的性能和特性进行了调查，并根据调查结果，编制了数据库和白砂-地图。提出了考虑白砂性质的新的试验方法。3.施工“白砂集料混凝土设计和施工建议”，包括白砂混凝土的制备、配合比设计、搅拌、浇筑、养护和检查，4.耐久性对白砂混凝土进行了耐久性试验，特别是对白砂混凝土的中和性、氯离子渗透性、抗硫酸盐性和ASR反应性进行了试验研究。5.实用性试验在上述试验的基础上，进行了一些实用性试验，例如在温泉环境中建造的桥梁结构的基础中的混凝土和用于预制PC梁的混凝土。此外，还对自密实混凝土和粉煤灰硬化材料的特殊适用性进行了研究。

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.