Paola Villoria Sáez

Estimation of construction and demolition waste volume generation in new residential buildings in Spain

The management planning of construction and demolition (C&D) waste uses a single indicator which does not provide enough detailed information. Therefore the determination and implementation of other innovative and precise indicators should be determined. The aim of this research work is to improve existing C&D waste quantification tools in the construction of new residential buildings in Spain. For this purpose, several housing projects were studied to determine an estimation of C&D waste generated during their construction process. This paper determines the values of three indicators to estimate the generation of C&D waste in new residential buildings in Spain, itemizing types of waste and construction stages. The inclusion of two more accurate indicators, in addition to the global one commonly in use, provides a significant improvement in C&D waste quantification tools and management planning.

Methodology for quantification of waste generated in Spanish railway construction works

In the last years, the European Union (EU) has been focused on the reduction of construction and demolition (C&D) waste. Specifically, in 2006, Spain generated roughly 47million tons of C&D waste, of which only 13.6% was recycled. This situation has lead to the drawing up of many regulations on C&D waste during the past years forcing EU countries to include new measures for waste prevention and recycling. Among these measures, the mandatory obligation to quantify the C&D waste expected to be originated during a construction project is mandated. However, limited data is available on civil engineering projects. Therefore, the aim of this research study is to improve C&D waste management in railway projects, by developing a model for C&D waste quantification. For this purpose, we develop two equations which estimate in advance the amount, both in weight and volume, of the C&D waste likely to be generated in railway construction projects, including the category of C&D waste generated for the entire project.

Legal Aspects which Implement Good Practice Measures in the Management of Construction and Demolition Waste

The construction industry, one of the most important ones in the development of a country, generates unavoid- able impacts on the environment. The social demand towards greater respect for the environment is a high and general outcry. Therefore, the construction industry needs to reduce the impact it produces. Proper waste management is not enough; we must take a further step in environmental management, where new measures need to be introduced for the prevention at source, such as good practices to promote recycling. Following the amendment of the legal frame applicable to Construction and Demolition Waste (C&D waste), important developments have been incorporated in European and International laws, aiming to promote the culture of reusing and recycling. This change of mindset, that is progressively taking place in society, is allowing for the consideration of C&D waste no longer as an unusable waste, but as a reusable material. The main objective of the work presented in this paper is to enhance C&D waste management systems through the development of preventive measures during the construction process. These measures concern all the agents intervening in the construction process as only the personal implication of all of them can ensure an efficient management of the C&D waste generated. Finally, a model based on preventive measures achieves organizational cohesion between the different stages of the con- struction process, as well as promoting the conservation of raw materials through the use and waste minimization. All of these in order to achieve a C&D waste management system, whose primary goal is zero waste generation.

Approach to the use of global indicators for the assessment of the environmental level of construction products

The European construction industry is supposed to consume the 40% of the natural European resources and to generate the 40% of the European solid waste. Conscious of the great damage being suffered by the environment because of construction activity, this work tries to provide the building actors with a new tool to improve the current situation. The tool proposed is a model for the comprehensive evaluation of construction products by determining their environmental level. In this research, the environmental level of a construction product has been defined as its quality of accomplishing the construction requirements needed by causing the minimum ecological impact in its surrounding environment. This information allows building actors to choose suitable materials for building needs and also for the environment, mainly in the project stage or on the building site, contributing to improve the relationship between buildings and environment. For the assessment of the environmental level of construction products, five indicators have been identified regarding their global environmental impact through the product life cycle: CO2 emissions provoked during their production, volume and toxicity of waste generated on the building site, durability and recycling capacity after their useful life. Therefore, the less environmental impact one construction product produces, the higher environmental level performs. The model has been tested in 30 construction products that include environmental criteria in their description. The results obtained will be discussed in this article. Furthermore, this model can lay down guidelines for the selection of eco- efficient construction products and the design of new eco-competitive and eco-committed ones.

Valorization of Building Retrofitting Waste as Alternative Materials in Gypsums

Received: June 06, 2017 Revised: July 10, 2017 Accepted: July 19, 2017 Abstract: Introduction: The lack of treatment of construction demolition waste (CDW) is a problem that must be solved immediately. It is estimated that the unused CDW generates an increase in the use of new materials close to 20% of the total materials consumed worldwide. Because of that, the use of CDW in building materials is an interesting alternative to guarantee their application. In the last years, many research works are being carried out in order to analyze the viability of using CDW as a substitute for the traditional raw materials that cause high environmental impact. However, much remains to be done, because these works generally characterize materials but not specific applications that allow the agents of construction to provide assurance required by the projects.

Redesign of Traditional Composites for the Building Construction Based on Circular Economy Criteria

In general, Construction and Demolition Waste (CDW) are debris generated in construction, rehabilitation, repair, or demolition works. Obviously, CDW generation depends on the growth and development of the building sector, and thus it is associated with the economic growth of the country. Despite these wastes can be easily recycled, Europe has a CDW recycling rate around 50%. This percentage is far from achieving the objectives set by the European Directive for the year 2020, i.e. recycle at least 70% (by weight) of waste generated. Therefore, from a life cycle perspective, it is necessary to reduce the environmental impact of buildings and promote circular economy criteria. Among these criteria are: reducing resources such as raw materials, replacing raw materials with high environmental impact (cement, plastics, steel, etc) by recycled materials and using buildings as a digester of CDW.

Analysis of the Relationship between Density and Mechanical Strength of Lightened Gypsums: Proposal for a Coefficient of Lightening

This article develops a relationship between the reduction of density in lightened gypsum and the addition of expanded and/or extruded polystyrene waste from the construction sector and their mechanical behavior. The equations determined in this study allow us to know the flexural and compressive strengths of a lightened gypsum/plaster compound once its density is known. The results show that there is an exponential relationship between the density of the compound and its strength. The methodology followed included a compilation of the results obtained in previous research works on lightweight gypsums, analyzing the relationship between density and mechanical strength and comparing them with the equations developed in this research. The results obtained by previous researchers have a good adjustment with the proposed models, and only perlite compounds present greater deviations in the compressive strength analysis. Also, a dimensionless lightening coefficient is defined which can help to determine the best application for a lightweight gypsum compound, comparing it with an ideal lightweight gypsum.