This is to show some basic data for introducing both circulated aggregate and recycled powder producing waste concrete. Standard-mixing design for 24MPa has been basically used and added and replaced normal aggregate with recycled powder made of waste concrete. In addition, polycarboxylate high-range water reducing agent has been used because recycled powder is missing adhesive strength and it is not compare with cement's adhesive strength. Compressive strength with powder mixture of 2%, 4%, 6%, 8%, and 10% has been decreased down to 80% of normal concrete material strength without recycled powder mixture. 200℃, 400℃ and 600℃ heated concrete were compressively tested in order to find out concrete strength resistant to high temperature. heat capacity was also tested, based on the expectancy of its low conductivity. In addition, thermal conduction test was tested in order to find out concrete insulation. According to this test, when concrete was tested by fire resistance, it using the circulation aggregate was same resulted by concrete using the natural aggregate. also, recycle powder was not effecting insulation performance. but it is fit to standard on concrete insulation of building law.

Risk level for each construction work can be very important factors to establish advanced prevention measures. But it is important how to produce it. There are three different methods to set it up for construction situation. They are as follows; 1) occurrence frequency = the number of accident workers of each work kind / yearly accident workers 2) occurrence frequency = the number of accident workers of each work kind / yearly workers 3) occurrence frequency = the number of accident workers of each work kind / the total workers All these three concepts(=averaged concept)are analyzed. Additionally frequency based on discrete curve, and severity based on continuous curve are also combined for producing risk level with more scientific approach. This risk level can be very useful to make prevention plan or take measures at construction sites. This is study result can change existing risk level concept to new concept of it, namely rail way work and in-water work showed be high risk level and RC work be low risk level, different from the situation which we have thought commonly, so far.

Establishing a framework, to explain the path to safety accidents considering major safety management factors such as physical conditions including on-site activities and workplace, as well as human factors as to labor, supervisors, or managers, would be effective as the basis to control project's risks by preventing disasters. Therefore, this study aimed to clarify the mechanism in safety management and disaster occurrence. In order to accomplish the purpose, it identified and classified the factors related to accidents, reviewed the causal relationships among them, and suggested the influence diagram. The results of this research are expected to contribute to reinforcing the preventive management, and facilitating the development of integrated site control system based on safety risks.

The small and medium construction companies are facing potential EHS(Environment, Health & Safety) of major accidents to cause casualties or a financial loss and increasing social responsibility. So, they have to voluntarily accomplish the EHS management system rather than passively with regard to EHS regulation. In this study, the framework of integrated EHS management system is developed based on cloud computing, and construction companies are to materialize self-regulation EHS process of construction workplace and to standardize the total EHS business process using the developed system. The proposed system also provides risk analysis, education/control and continuous improvement for EHS tasks and users can easily access the system on the web at a low price through cloud computing service. Eventually, the integrated system contributes to the managerial improvement by minimizing economic and physical loss caused by construction accidents.

Analysis of benthic micro-invertebrate community structure from the Pyeonghwaui Dam was investigated from May 2006 to October 2008. Total taxa of benthic micro-invertebrates were 5 phylum, 8 class, 15 order, 44 family, and 97 species in 2006, and 5 phylum, 7 class, 15 order, 48 family, 103 species in 2008. Mean dominance index at St. 1 to St. 5 were 0.36, 038, 0.38, 0.21 and 0.29. Mean species diversity at St. 1 to St. 5 were 3.84, 3.34, 3.13, 4.84 and 4.28. Although the dominance index of Lentic area was higher than Lotic, but the diversity was lower than Lotic area.

The Purpose of this study was to comprehend the influence that worker's job stress caused by the distinct characteristics of construction work affect on construction management. Proven through previous studies of job stress measurement method, physical environment, job demands, job autonomy, interpersonal conflict are derived as typical factors. We analyzed causal relationships between the factors using structural equation modeling under the hypothesis that job stress have effect on the construction management. As a result, successful job stress management for construction management plan is proposed.

Risk level for each construction work can be very important factors to establish advanced preventionmeasures. But it is important how to produce it. There are three different methods to set it up for consturuction situation. They are as follows; 1) occurrence frequency = the number of accident workers of each work kind / yearly accident workers 2) occurrence frequency = the number of accident workers of each work kind / yearly workers 3) occurrence frequency = the number of accident workers of each work kind / the total workers All these three concepts(=averaged concept)are analyzed. Additionally frequency based on discrete curve, and severity based on continuous curve are also combined for producing risk level with more scientific approach. This risk level can be very useful to make prevention plan or take measures at construction sites. This is study result can change existing risk level concept to new concept of it, namely rail way work and in-water work showed be high risk level and RC work be low risk level, different from the situation which we have thought commonly, so far.

The study focuses on analysing situation of disasters and characteristics in construction process which the technical construction firms accomplish. Besides, the study aims at the role and responsibilities of technical construction firms in construction safety. It is found out by a questionnaire and interviews in this study that safety control and management have a key role to prevent accidents in construction projects. Based on the result of the research, it is concluded that institutional improvement and support strategies are suggested and that additional to the support of the government and institutions in charge of the field of construction safety the effort of the first contractor, the second contractor and the laborer it is also important.

In terms of deregulation requests from business, incidents at construction sites are rapidly increasing after reducing the regular safety training hours. Especially, to prevent incidents through safety trainings for construction site workers, who have lots of hazardous tasks than general manufacturing, is not only to protect property of both the companies and the country but also to increase their profits. That is why there are loud voices regarding that the safety training is a core mandatory to prevent industrial incidents. But, most companies, as soon as the deregulation for safety training is implemented, mitigated conducting safety trainings to prevent incidents. With this, the incidents are currently to be increased and caught in a vicious circle of many incidents at the smaller companies because of their absentmindedness regarding safety training due to their poorness as subcontractors of major companies, comparing to major companies. This study explains that the difference between managers and workers are existing about safety awareness and knowledge. And, we confirmed that the educational factor led by deficiency of safety awareness and knowledge was the major factor.