Abstract
This paper focuses on the relationship between intervals of a RCD concrete placement and shear strength of the horizontal joint under the condition of non-treatment by a laboratory test. The purpose is to realize of the continuous RCD construction method, or getting up speed and reducing laborious works. It is based on the conception that it is able to decrease the frequency of green cutting and mortal spreading of the RCD construction method by expecting an ability of the combination of concrete itself. The results of this study show that the shear strength of horizontal joints compared that of the concrete between them decrease more as the time to place the concrete longer, even in a few hours from the placement in which there aren't any hydrate by an observation of the scanning electron microscope. This means that it is necessary to examine the effects on the shear strength of the horizontal joint from points of view of the mix proportion and the methods of the concrete compaction.
