讲座题目：Unique grouting material composed of calcium phosphate compounds
主讲人：Prof. Satoru Kawasaki, Hokkaido University, Japan
主持人：Dr. Varenyam Achal
开始时间：2016-5-18, 1 PM
讲座地址：生科辅楼119会议室
主办单位：生态与环境科学学院 科技处
报告人简介：Prof. Satoru Kawasaki is Professor at Hokkaido University, Japan. He did his PhD from Tottori University, Japan. He is faculty in engineering and head of Laboratory of Biotechnology for Resource Engineering. His field of specialization is in environmental geotechnics and geoenvironmental engineering. His current research includes development of new methods for ground improvement, biological grouting, biodeterioration of rock, and preservation method for stone cultural heritage. He has published more than 50 research articles in related area.
报告摘要：In engineering as well as science, it is essential to learn from nature. In nature, several types of minerals, such as calcium carbonate, calcium sulfate, calcium phosphate, calcium oxalate, silicate, iron oxide, and so on, are precipitated by living things. These are called biominerals and are promising as engineering materials because they have considerable strength and low environmental impact. To use calcium phosphate compounds (CPCs) for ground improvement measures such as the reinforcement of soil and rock, a fundamental examination of the development of new grouting materials composed of CPCs was carried out. CPCs exist as phosphate rocks (e.g., fluoroapatite) in the natural environment and also as an important inorganic substance (e.g., hydroxyapatite) in living things. As grouting material, CPCs have unique physicochemical properties and many advantages such as considerable mechanical strength, self-setting property, pH dependence of precipitation, non-toxicity, and recyclability. The most suitable conditions for CPC precipitation were determined by an in vitro examination using calcium and phosphate stock solutions. Subsequently, unconfined compression tests using sand specimens cemented by CPCs were conducted. The specimens were observed by scanning electron microscopy and analyzed by using an energy dispersive x-ray fluorescence spectrometer. The results obtained in this study indicate the practical feasibility of using unique and new CPC grouts as chemical grouts because of their self-setting property and as biogrouts because of their crystal structure and the pH dependence of precipitation.