High performance composite structures with combination of expansive concrete and fiber reinforcements

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In this study, in order to experimentally investigate the flexural behaviors of high performance composite structures, trial combinations of high strength expansive concrete and fiber reinforcements were carried out. Fiber reinforcements consist of short fibers and continuous fiber reinforcements. A depth of reinforced concrete member is limited to 10 cm. Target compressive strength of expansive concrete is larger than 80N/mm^2. High strength expansive concrete can be applied to composite steel structures for the purpose of not only to protect steel corrosion but also to introduce chemical prestress effectively by using higher expansive energy of the expansive concrete.High performance composite structures can be attained by the prominent combination of steel members and high strength fiber reinforced expansive concrete. From the research results, a design method of high performance composite structures is proposed and following items are gained.1)High strength expansive concrete with … More short carbon fibers or short vinyl fibers can be manufactured. Compressive strength of the expansive concrete is larger than 80N/mm^2.after selecting appropriate combinations of not only mix design of concrete but also quantity of high performance expansive additive and content of short fibers.2)Chemical prestrains are lineally distributed across the height of composite steel girders if bond strength between a concrete slab and a steel girder is strong more than enough. However linear distributions of chemical prestrain could not be gained for the height direction if the poor bond strength is existed around a edge of the girder. The phenomena can be seen easily for the higher composite steel girders.3)Though longitudinal chemical prestrains at the upper position of the steel girder are strongly affected, chemical prestrains are a little larger at the position far from the steel girder due to weaker restraint by the steel girder.4)Higher flexural behaviors of the composite steel girder can be attained if the bond strength between concrete and steel girder were strong enough. Therefore the effect of chemically prestressed concrete depends on the soundness and degree of the bond strength.5)Radial directional work-done by the expansive concrete is almost the same as that of uni-axial A method restraint even if the thickness of inner steel pipe and of outer steel pipe are varied about five times. Less