Study on Effect of Heat Elimination by Pipe Cooling System in Beam Using High Strength Engineered Cementitious Composites

摘要

In the field of construction, the innovative technique using the coupling beam making use of characteristics of the Engineered Cementitious Composites (ECC) has been proposed, for instance the energy absorption by concentrating the seismic force in the core wall is implemented in high-rise R/C structures (Kanda 2006). Moreover, study with the aim of high strengthening of the coupling beam has been carried out. However, in the high strengthening coupling beam, possible temperature increase in a relatively massive element section exceeding 100 °C due to the heat of cement hydration has been concerned. When temperature in the member exceeds 100 °C due to the heat of cement hydration, the performance of organic fibers (the high-strength polyethylene fibers) is significantly reduced. Hence, in order to control the excessive temperature rise due to the heat of cement hydration, the analytical study was carried out for a pipe cooling system adopted as a countermeasure. On the basis of results of temperature measurement for the ECC coupling beam, design of the pipe layout to control the maximum temperature in the member lower than 90 ° C was carried out and thermal properties were also identified. In this report, the experiments for evaluating the effectiveness of pipe cooling were described and the results were discussed.