Paper and Presentation by Kyong-Ku Yun, Kyong Namkung, Seung-Yeon Han, Kyeo-Re Lee from ASCP 4th Concrete Pavements Conference 2017
The main objective of this study is to develop a simple and economical two-lift concrete pavement construction method using cellular spraying technique. In this method, cellular is added into the ready mixed concrete to increase its workability and to enable onsite silica fume and polymer powder addition, which was difficult due to the high fineness of the powders. The addition of cellular facilitates the mixing process and dispersion of the powders due to its surfactant effect. Hence, onsite production of high-performance concrete is achieved in this method. EDS test was used to analyze the dispersion of silica fume in the cellular sprayed concrete by incorporating various amount of cellular.
The change in W/B of the concrete due to the addition of cellular was also analyzed by using 30% cellular and 40% cellular mix variables since W/B has a direct effect on the strength and durability of the concrete. In addition, rheology test was performed in order to analyze the possibility of clogging in the pump car during spraying. The initial plastic viscosity and flow resistance of the mix were measured to check workability of the concrete by the amount of cellular incorporated. A mock-up test was carried out on site to identify the optimum mixing rate of silica fume and polymer powder; the result of the tests performed was analyzed and mix design was prepared for the bottom and top layer of cellular sprayed concrete based on the analysis.
Finally, it is planned to conduct a test construction of high-performance concrete pavement by applying cellular sprayed construction method.