In 2016, the construction sector in Costa Rica accounted for 4.4% of the GDP and its constructions covered around 10.5 million square metres. The drive of this activity entails the use of a large amount of virgin materials and the production of a lot of solid waste.
The management of materials is one of the important aspects that those involved in the process of undertaking works have to consider. Not only must they comply with particular requirements, such as those relating to quality, function, cost, durability and resistance, but they must also ensure that they are used and handled efficiently, resulting in a reduction in waste production during the works process. For that reason, materials are a production element that have to be taken into account during the different life cycle stages of a project: planning, design, execution, operating use, maintenance and, finally, the useful life of a building.
The production of a large amount of waste during the execution stage of a project is common. While some waste is inherent to the construction process, the majority is discarded materials that are still recoverable; in other words, materials that may be reused or recycled. The main idea of appropriately managing materials is to reduce such amount.
The Technological Institute of Costa Rica, as part of its mission to provide knowledge to the sector, worked with the Costa Rican Chamber of Construction, with support from the regional programme the Cooperation Platform for Northern Latin America (COPLAN) and the German Cooperation Agency (GIZ), in drawing up a guide for efficiently handling construction materials. In producing this guide, an analysis was conducted on the ordinary and hazardous waste found on building construction sites in Costa Rica. The laws and regulations that affect the sector in terms of its waste are set out in the guide, along with good practices regarding construction material and waste management. Furthermore, the guide has a number of annexes in which a waste management plan is proposed, as well as datasheets relating to trade, types of materials produced as waste and control methods, among others.
Waste on the most common construction projects.
The results set out in the guide were obtained from surveying 52 small, medium and large companies. Based on the survey, it was established that the ordinary waste most produced on building construction projects is as follows: steel (pipes), aluminium (frames and ceiling), cement bags (packaging material), electric cable, cardboard, ceramic, copper (pipes), concrete, reinforced concrete (concrete with steel), polystyrene, tools (work equipment), iron, bricks, corrugated sheets (zinc corrugated material), brass and bronze (locksmith-related elements), wood (mixed and clean), insulating material, plant material (soil and land clearance material), melamine resins, paper, plastic (packing material), lightweight wall waste (Fibrolit, etc.), natural stone waste, marble and granite, PVC waste, plaster waste, mortar, coating, forging material, clothing (shoes and helmets) and glass. The hazardous and specially treated waste indentified is: acids, solvents and detergents, concrete additives, release agents, oil containers, lubricants, brake fluids, fuels, metal paint containers, plastic paint containers, wood treated with chemical products, paint, asbestos waste, asphalt waste, fibreglass waste, silicone welding waste and other sealants, contaminated soil, cloths, brushes and other tools that contain chemical products (used for cleaning surfaces and equipment) and fluorescent tubes.
The study also identified the reasons for which waste is produced and it established good practices to better deal with materials, resulting in a reduction in the waste generated. The good practices were grouped together according to the activities of design, works execution, purchase management and acquisitions, waste and material management, as well as other activities, and were set out in order of their importance in each corresponding activity. Some good practices are also included with the aim of them becoming an important tool with which to manage materials. It is envisaged, if the majority of the good practices are complied with, that there will be reduction in the actions behind waste production and it will help materials to be used in a more efficient manner.
PhD. Lilliana Abarca Guerrero, MSCE.
Ana Grettel Leandro Hernández, Ing. Carolina Rojas Brenes
Instituto Tecnológico de Costa Rica