Abstract
With the latest development of Prefabricated Concrete Constructions, some reports are appeared which discribe the use of bonding strength of inserted steel bar to connect the concrete members. We are mentioned to aply the expanding admixture to the grouting mortar for incresing the bonding power of this connection method. Generally the expanding admixture DENKA CSA, is trending toward the decrease of bonding strength. But if we turn the expansive force to inside by binding of the expansion, the bonding strength and the concrete strength will be in increase in consequence of concrete becoming close. The purpose of this thesis is to investigate these effects of DENKA CSA. Formally we used DENKA CSA 10% of Portland cement for protects the shrinkage of the concrete, but in this experiment we take mix-ratio amount to 30%. The specimens are combination of various length steel-pipe and inserted bar with the grouting mortar. In consequence, the effect of this connection is efficient to DENKA CSA of 30% and the inserted length of 30 times of steel rod diameter.
