TABLE OF CONTENTS Z. CHEN, S. KATOH AND T. MORIYOSHI
Research Institute for Solvothermal Technology 2217-43 Hayashi, Takamatsu, Kagawa 761-0301 Japan
E-mail: chen@kagawa-isf.jp
A new and rapid method for making calcium silicate building materials was developed by applying microwave-steam curing and with the addition of a small amount of NaOH. Quartz sand and Ca(OH) 2 were mixed at a fixed ratio, and then knead with a small amount of NaOH and H 2O. The resulting slurry was formed in 15 15 30mm mold, and then pre-dried. The pre-dried block was treated with microwave- steam curing below 100 C in an open system. Useful calcium silicate materials with compressive strength of about 50MPa were obtained. Results also showed that it is possible to shorten curing time to less than 3min by pulse microwave irradiation. This method is good for saving energy considering low operating temperature and short curing time compared to the conventional method. This report describes the effect of raw materials ratio, microwave power and irradiation type and curing time. Moreover, the properties of the obtained materials are investigated.
Recently, there has been a growing interest in the application of microwave irradiation due to difference in heating mode compared to the conventional method. Heating by microwave originates from the inner part of material, while formation of "hot-spots" is also thought possible. Considering short-time and energy-saving advantages, microwave heating had been applied significantly to chemical synthesis, and a lot of researches had been done in this regard. Especially, promising...
