固化材として酸化マグネシウムを用いた組積耐力壁用非焼成土ブロックに関する研究

In order to address global environmental problems, the construction industry has introduced various strategies to save resources and energy, and to reduce the amount of waste produced. Earth materials have many environmental advantages, such as the abundance of resources and minimal contamination during disposal. Earth materials have traditionally been used in Japan, such as for clay walls on bamboo lathing and rammed-earth. These methods are problematic in modern day construction because they require a high degree of skill and many processing steps. This paper proposes the use of non-burnt earth block as the masonry unit for load bearing wall. Since non-burnt earth block does not require large facilities or high energy costs for their construction, they may be widely adopted in various countries around the world, including in developing countries.When non-burnt earth block is used in construction, simple dry solidification of the earth can result in problems with the strength and water resistance. Thus, it is necessary to stabilize the materials to improve their performance. Magnesium oxide is a low alkaline solidification material with minimal environmental burden that may be used to enhance the compressive strength and water resistance of earth block. This study puts its focus on making mechanism that can find the optimum mix proportions of earth block that satisfy the required quality and manufacturing conditions. The details of the experiment are as follows:Experiment 1. These experiments were performed to identify the factors that influence the strength development of MgO. Compressive strength tests and thermal analysis (TG-DTA) were performed on MgO mortar, exploring factors such as different water-MgO ratio and curing conditions. Test results indicate that the hardening mechanism of MgO is due to the formation of magnesium hydroxide, and this phenomenon was most notable at the beginning of the sealed curing. Furthermore, it was found that the compressive strength increases as the water-MgO ratio decreases.Experiment 2. These experiments were performed to confirm which factors influence the production conditions and quality conditions of the earth block stabilized with MgO. From the experimental results, the following things were confirmed: (1) The state of the mixing sample is related to the proportion of fine particles (clay and sand-blended clay passed through 75 μm + MgO) and water. (2) The length change rate can be estimated from the proportion