Application of life cycle assessment (LCA) methodology and economic evaluation for construction and demolition waste: a Colombian case study

The construction industry consumes more raw materials and energy than any other economic activity and generates the largest fraction of waste, known as construction and demolition waste (CDW). This waste has significant environmental implications, most notably in South American countries such as Colombia, where it is handled inappropriately. This study evaluated the management processes currently used for fractions of construction and demolition waste generated in Ibagué (Colombia). The environmental impacts of the management of 1 kg of CDW were also calculated. Other CDW management alternatives were evaluated. The percentage of the fraction of the waste and the treatment or management processes used were modified to determine its environmental and economic viability. The information was obtained through telephone interviews and visits to recycling plants, construction companies, quarries, government entities, and inert landfills. It was completed with secondary sources and the Ecoinvent v.2.2 databases. Life Cycle Assessment (LCA) methodology and the SimaPro 8 software were used to calculate the environmental impacts. An economic study of each management process and each alternative was also carried out. A comparison of the other options revealed the current choice contributes most to the environmental impacts in all categories. This study indicates that the most beneficial alternative in environmental and economic terms in Ibagué (Colombia) is where 100% of the metals are recovered, 100% of excavated earth is reused, and 100% of the stone waste is recycled (alternative 3). This alternative remained the most favorable when a sensitivity analysis was carried out with different distances (30 km and 50 km).