Construction and demolition waste applications and maximum daily output in Spanish recycling plants

Analysis of the socio-economic and environmental impacts of construction waste and management practices

This study aims to analyze the significant socioeconomic and environmental impacts of construction waste and to indicate management strategies. An extensive review of the literature and interviews with construction experts were used to identify waste impact factors. Then a questionnaire survey was conducted based on a five-point Likert scale and the data were analyzed by descriptive statistics. The result showed that construction waste becomes a challenge for almost 95.71% of ongoing construction projects. However, only 57.14% of the construction companies have recorded and measured the volume of material waste. From purchased materials, 6–10% is recorded as waste that lead to project cost overrun. In addition, there is no professional assigned to handle waste issues in 75.71% of construction companies. The study also indicates that project cost overrun, pollution of the environment, reduction in profit and failure of construction firms, excessive consumption of raw materials, and public health and safety risks are ranked as the five major impacts of construction waste, respectively. Employing a waste management officer, using prefabricated or off-site components, implementing strong onsite management practices, reusing and recycling materials leftover on the sites, and practicing green building codes and specifications are measures devised to mitigate construction waste and its impacts.

Financial and economic evaluation of construction and demolition waste recycling in Hanoi, Vietnam

Increasing waste generation and the absence of a formal recycling industry are exacerbating the inadequacy of Construction and Demolition Waste (CDW) management in Hanoi, Vietnam. This study assesses potential CDW recycling in Hanoi by estimating the prospective supply of and demand for CDW recycling plants and evaluating their likely costs and benefits. Supply of concrete waste was calculated based on the weight-per-construction-area method whilst demand for recycled concrete aggregates (RCA) was determined by estimating the amount of aggregates for road construction in Hanoi from 2013 to 2017. Two potential models of CDW recycling plants were considered: a stationary plant and a mobile plant, with capacities of 1,000 and 360 tons/day, respectively. Our findings reveal that demand for RCA exceeds waste concrete supply, suggesting a promising market for RCA. Positive Net Present Value and Internal Rate of Return values of the stationary plant indicate its feasibility as an investment option. Meanwhile, the introduction of mobile recycling plants might require governmental intervention to internalize recycling positive externalities. Supporting policies might include a combination of a virgin material tax, green public procurement, and quality standard development.

The Experimental Study of the Utilization of Recycling Aggregate from the Demolition of Elements of a Reinforced Concrete Hall

The article shows a case study as to whether the thermal and mechanical recycling of concrete is suitable for concrete debris from the demolition of structural elements of a 30-year-old industrial hall. The experiment included 10 series of new composites made from heated recycled concrete aggregate (HRCA) subjected to different variants of heat treatment and one additional control series with only natural aggregate (NA). The compressive strength of the new concretes has been determined. The microscopic observations of HRCA have also been made. The test results revealed that proper heat treatment of concrete rubble makes it possible to obtain a high-quality recycled coarse aggregate, which can be used as a 100% replacement for natural coarse aggregates in new concretes.