Investigation on Construction Solid Wastes Management within Building Sites Environment in Kigali City
Authors:   Jomo Kenyatta University, Department of Construction Project Management,, Habineza F.M , Nsengiyumva J.N ,   University of Rwanda. Soil and Water Engineering,, Gwaya Dr Abednego O. ,   Senior Lecturer, Jomo Kenyatta University of Agriculture and Technology,, Diang’a Prof. Stephen ,   Senior Lecturer, Jomo Kenyatta University of Agriculture and Technology,
Published: April 2020

The largest volume of construction work in the country is mainly concentrated in this city and improper demolition of construction waste cause improper handling to construction sites. The general objective of the study will investigate on the construction solid and demolition waste management in Kigali City. A cross sectional survey among the construction companies was conducted from 60 contractors by purposive sampling. The research targeted all construction practitioners in various active sites of Kigali city. Sources of data for this study were obtained through questionnaires, interviews and site surveys. Descriptive statistics will be applied to analyze quantitative and qualitative data through SPSS 16 and STATA 13.0 computer package. Analysis of Variance was used to test the relationship between Methods of CSWM and its types of demolished waste by level of satisfaction. The key findings showed that the most construction solid waste identified on construction sites were woods; scrap metals; cement; bricks and trees respectively and the construction companies suggested that those wastes are available on their construction sites and they should be demolished properly. The second category of CSWM identified were insulation; nails; plaster; rocks; dirt and asbestos respectively according to their means and standard deviation. Furthermore, for thermal treatment, the study findings concluded that there is open burning and the respondents were fairly on the adopted methods for waste treatment. Secondary there are incineration and Pyrolysis which are used to treatment waste from construction sites and all respondents were not satisfied on their application to treat waste. Lastly the study findings concluded that there are gasification and is not usually used as the heads of sites were very unsatisfied. The cost associated with SWM for practitioners and it is ranged from 6,000,000Frws-9,000,000Frws used cost of Vegetation/ top soil (site clearance), cost of reinforced concrete, cost of Scrap metals, cost of rocks and municipal waste respectively to clean the construction environment.The next category of cost was valued in ranged of waste costing above 3,000,000Frws-6,000,000Frws and those were the cost of bricks/ tiles demolition, cost of wooden materials and other non inert waste demolition, cost of debris of pipes demolition, cost of sewage demolition and cost of chemical waste (waste oil, lubricants, paints& solvents) demolition from the construction sites respectively. The revenues associated on CSWM ranged from 6,000,000Frws -9,000,000Frws for Vegetation/ top soil (site clearance), Reinforced concrete, Scrap metals, Wooden materials and other non inert waste and Municipal waste management that may generate high level of incomes; and from 3,000,000Frws-6,000,000Frws for Rocks, Sewage and Chemical waste (waste oil, lubricants, paints& solvents) waste