C&D waste management is an area where attention needs to be paid for as the construction industry is considered to be one of the key solid waste generators. Mainly, C&D waste get generated through the new construction, renovation of buildings, and through the demolition of buildings and structures. Hence, it is necessary to manage the C&D waste. In order to manage the C&D waste, it is necessary to identify the types and origins of waste. Thus, the aim of the paper is to identify the types of C&D waste and their origins of generation. This paper critically reviews secondary data and findings of eight case studies under the qualitative approach. Through the case study findings, it was evident that plywood, concrete, cement, steel offcuts, blocks bricks, sand, soil, wood, polythene and food waste as the main types of C&D waste in Sri Lankan construction sites. Further, design changes, transport, human mistakes, quality of works, client changes and mismatches in required materials are identified as the key origins for C&D waste generation in Sri Lankan construction sites. Therefore, to achieve the aim of the paper, types of C&D waste materials and origins of C&D waste generation were identified.

The construction industry, being a large industry, generates a massive amount of Construction and Demolition Waste (CDW). Strategies such as the 3R concept (Reduce, Reuse, Recycle) and waste hierarchy are used in the industry for CDW management. However, CDW management is still in its primary stage. The Zero Waste (ZW) concept has the potential to eliminate CDW. Thus, this study aimed to identify how the 3R concept can be used in the construction industry in Sri Lanka to eliminate CDW and achieve ZW. A comprehensive literature survey and a qualitative research approach consisting of eight case studies were used for data collection. Manual content analysis followed by cross-case analysis was used to analyze the data collected through twenty semi-structured interviews. The study identified ways of minimizing wastage of materials by using the reducing and reusing concepts. Although none of the construction sites had recycling machines, recycle strategy was implemented at the sites for waste materials by hiring recyclers. Thus, this study proves the feasibility of achieving ZW through the 3R concept by adopting an effective waste management plan at the initial stages of construction projects.