Study on Permanent Formwork System Using Glass-Fiber Reinforced Concrete Panels

The shortage of skilled laborers in Japan has been pointed out as one of the causes of the deterioration of buildings in recent years. This paper presents a new permanent formwork system designed to simplify complicated procedures in the fabrication of form. Glass-fiber reinforced concrete panels (G.R.C. panels) and aluminum frames are mainly used in the new formwork system. The panels are used for the sheathing boards which contain the freshly mixed concrete, and the aluminum frames support the panels to hold the configuration of the panels. Line scratching is made on the inner surface of the panels, a method which improves the adhesion strength between the panel and the concrete after the hardening of concrete. Construction experiments using the new formwork system were made to investigate the efficiency of the system. The experimental data, such as the accuracy of dimension at the finish of work, the adhesion strength between the panel and the concrete, and the time of work, were compared with the date used in a conventional formwork system. The conclusions are as follows: the time of work and human energy required for the fabrication of these panels were effectively shortened by introducing the new formwork system: a deterioration of adhesion strength was not observed over a period of several months: and, therefore, the new formwork system is superior to the previous system and available for practical use