Practical Application of Structural Super Lightweight Aggregate Concrete

近年来，日本开发出了超轻质人工骨料。比重在0.8 ~ 1.2左右，吸收率小于3.0%。抗压强度是常规人工集料的两倍以上。在本研究中，研究了这种结构超轻混凝土的实际应用。作为研究工作的第一步，在试验的基础上对SLC梁的断裂性能、加筋和预应力SLC梁的抗剪性能进行了研究。作为本研究的结果，得到了以下发现。(1)在相同抗压强度水平下，SLC的断裂能远低于普通骨料混凝土。SLC梁的抗剪承载力也表现出相同的趋势。(2) SLC抗压强度的增加并没有带来断裂能的显著增加。(3)从材料的角度来看，短纤维（如聚乙烯醇短纤维）的混纺对提高抗剪能力是非常有效的。预应力的使用对于提高SLC梁的抗剪能力也是非常有效的。第二步，尝试了提高SLC梁抗剪能力的两种对策。一种是故意降低SLC梁的抗压强度，另一种是超轻骨料与普通骨料混合使用，如碎石。经研究证实，无论超轻骨料比重如何，这两种方法都是相当有效的。最后，针对SLC的实际应用，进行了SLC组合梁的试验设计。并利用计算机图形学进行了美学评价。从试验设计来看，SLC复合梁可以将上部结构的自重降低到传统PC梁的近50%。SLC可以提供细长、智能的混凝土结构。少

Recently, super lightweight artificial aggregates have been developed in Japan. The specific gravity is around 0.8 to 1.2, and the absorption ratio is less than 3.0%. The compressive strength is more than double of conventional artificial aggregates. In this research, the practical application of this structural super lightweight concrete (SLC) has been investigated.As the first step of this research work, fracture properties of SLC, and shear resisting capacities of reinforced and prestressed SLC beams have been investigated based on the experiments. As the result of this study, the following findings have been obtained. (1) The fracture energy of SLC is much lower than normal aggregate concrete having the same compressive strength level. The shear capacity of SLC beams also shows the same tendency. (2) The increase in the compressive strength of SLC does not provide the significant increase in the fracture energy. (3) To improve the shear resisting capacity, the mix of short fiber, s … More uch as polyvinyl alcohol short fiber, is very effective in the material viewpoint. The use of prestressing is also very effective to improve the shear capacity of SLC beams.As the second step, two countermeasures have been tried to improve the shear capacity of SLC beams. The first one is the intentional decrease in the compressive strength of SLC beams, and another one is the mixed use of super lightweight aggregates with normal aggregates, such as crushed stone. After the research work, it is confirmed that these two methods are quite effective regardless of the specific gravity of super lightweight aggregates. Finally, for the practical application of SLC, the trial design of SLC composite girders has been carried out. The aesthetic evaluation by using the computer graphics is also performed. From the trial design, SLC composite girders can reduce the dead weight of super structures to almost 50% of the conventional PC girders. SLC can provide the slender and smart concrete structures. Less