Recommendations for the Management of Construction and Demolition Waste in Treatment Plants

Construction and demolition waste consists approximately of one third waste generated in the European Union. The recycling of this stream waste will provide ecological and sustainable benefits. Recycled aggregates from construction and demolition waste are clearing a path into civil constructions, as substitutes for natural aggregates. The possible applications of recycled aggregates on infrastructure construction projects will depend on the quality of the recycled aggregates mainly. This will be determined by the nature and the origin of the construction and demolition waste, and the treatment system undergone. Hence, this work proposes recommendations for the handling of construction and demolition waste in treatment plants

Promotion of Circular Economy: Steelwork Dusts as Secondary Raw Material in Conventional Mortars

Among the actions proposed by the European Union for the implementation of Circular Economy is the use of waste as a secondary raw material (SRM). During the fusion of the scrap, a steel dust is generated, named Electric Arc Furnace Dust (EAFD). The EAFD is composed mainly of potentially leachable heavy metals, so is classified as “hazardous” waste. Around the world, approximately 70% of this waste is deposited in landfills, with a previous treatment through cement-based materials to prevent the metals’ mobility. However, this action is not in accordance with the Circular Economy concept due to the greater use of resources and the loss of deposited metals. The present investigation analyses the use of EAFD as SRM in conventional mortar production for its use as a construction material. Different substitution percentages (25%, 50% and 100%) were used replacing siliceous filler by EAFD. The investigation analysed the behaviour of conventional mortars by tests of workability, compressive strength, water absorption by capillarity and leaching behaviour in granular and monolithic state. The results obtained indicate a slight improvement in mechanical behaviour with the incorporation of EAFD, the reason why its use as SRM in conventional mortars would benefit the construction industry and would encourage the Circular Economy. From an environmental point of view, the mechanisms of Pb fixation should be improved in granular state

Catalogue of Pavements with Recycled Aggregates from Construction and Demolition Waste

Construction and Demolition Waste come from debris generated during construction, renovation and demolition of buildings, roads, and bridges. Recycling and reuse are essential in terms of sustainability, mainly from an environmental point of view. Although the recommendation of the use of these recycled aggregates is currently included in some technical specifications, its use is still not widespread due mainly to the lack of knowledge on their technical application. This work is a compilation of the recommendations proposed in the “Catalogue of road pavements with recycled aggregates”, supported by the construction of experimental stretches. It proposes different structural sections for road pavements by using recycled aggregates

Photocatalytic Recycled Mortars: Circular Economy as a Solution for Decontamination

The circular economy is an economic model of production and consumption that involves reusing, repairing, refurbishing, and recycling materials after their service life. The use of waste as secondary raw materials is one of the actions to establish this model. Construction and demolition waste (CDW) constitute one of the most important waste streams in Europe due to its high production rate per capita. Aggregates from these recycling operations are usually used in products with low mechanical requirements in the construction sector. In addition, the incorporation of photocatalytic materials in construction has emerged as a promising technology to develop products with special properties such as air decontamination. This research aims to study the decontaminating behavior of mortars manufactured with the maximum amount of mixed recycled sand without affecting their mechanical properties or durability. For this, two families of mortars were produced, one consisting of traditional Portland cement and the other of photocatalytic cement, each with four replacement rates of natural sand by mixed recycled sand from CDW. Mechanical and durability properties, as well as decontaminating capacity, were evaluated for these mortars. The results show adequate mechanical behavior, despite the incorporation of mixed recycled sand, and improved decontaminating capacity by means of NOx reduction capacity

Mechanical Performance of Concrete Made with the Addition of Recycled Macro Plastic Fibres

For many decades, researchers have been working on finding innovative and sustainable solutions to address the enormous quantities of plastic waste that are produced every year which, after being collected, are transformed into energy, recycled, or sent to landfills. Giving a second life to plastic waste as a material to be incorporated, in the form of macro-fibres, into concrete, could be one such solution. The purpose of this study was to analyse the mechanical and physical behaviour of the hardened concrete reinforced with macro plastic fibres (RPFs) obtained from food packaging waste (FPW) discarded during the packaging phase. By varying the quantity of macro-fibres used, physical and mechanical properties such as compressive strength, modulus of elasticity, flexural strength, and toughness were evaluated. It was observed that, although the presence of macro plastic fibres reduced the mechanical resistance capacity compared to that of traditional concrete, their contribution proved to be of some importance in terms of toughness, bringing an improvement in the post-crack resistance of the composite material. This innovative mixture provides a further impulse to the circular economy

Feasibility of Using Unbound Mixed Recycled Aggregates from CDW over Expansive Clay Subgrade in Unpaved Rural Roads

Social awareness aims to increase practical skills, such as sustainable development, which seeks to increase the use of different types of waste in construction activities. Although insufficient attention is sometimes given to these actions, it is essential to spread information regarding new studies in the field of waste recycling, which encourages and promotes waste use. Reusing and recycling construction waste in the creation of buildings and infrastructure are fundamental strategies to achieving sustainability in the construction and engineering sectors. In this context, the concept of waste would no longer exist, as waste would become a material resource. Therefore, this study analyses the behaviours of two unbound mixed recycled aggregates (MRA) in the structural layers of an unpaved rural road with low traffic (category T43). The sections were built on inappropriate soil (A-7-6) with a high degree of free swelling. The experimental road consisted of three sections: the first was made with natural aggregates (NA) that were used as a control, the second was composed of MRA in the subbase and NA in the base, and the third section was completely composed of MRA. The materials were characterised in the laboratory. The behaviours of the structural layers in the experimental road were determined by controlling compaction (“in situ” density and moisture) and measuring the deflections and load capacity (deflectometer) during the 18 months after construction. The results show that the sections made with recycled aggregates meet the technical specifications required by General Technical Specifications for Road and Bridge Works (PG-3). Therefore, the water-soluble sulphate content and Los Angeles abrasion coefficient limits can be increased for recycled aggregates without compromising the quality of this type of road with low traffic. To the best of our knowledge, this is the first study regarding the use of unbound MRA made from construction and demolition waste (CDW) in the construction of an unpaved rural road with low traffic on an expansive clay subgrade

Upscaling the Use of Mixed Recycled Aggregates in Non-Structural Low Cement Concrete

This research aims to produce non-structural concrete with mixed recycled aggregates (MRA) in upscaled applications with low-cement content. Four slabs were executed with concrete made with different ratios of coarse MRA (0%, 20%, 40% and 100%), using the mix design, the mixing procedures and the facilities from a nearby concrete production plant. The analysis of the long-term compressive and splitting tensile strengths in concrete cores, extracted from the slabs, allowed the highlighting of the long-term high strength development potential of MRA incorporation. The study of cast specimens produced in situ under the same conditions as the slabs showed, firstly, that the use of MRA has a great influence on the properties related to durability, secondly, that the loss of compressive strength for total MRA incorporation relative to control concrete increases proportionally with the class strength, and, thirdly, that the mechanical properties (including Schmidt hammer results) from the concrete slabs showed no significant differences relative to the control concrete for coarse aggregates replacements up to 40%. Therefore, this upscaled experimental study supports the application of concrete with 100% coarse MRA incorporation and low cement content in non-structural civil works such as bike lanes, gutters, ground slabs, leveling surfaces, and subgrades for foundations. To the best of the authors’ knowledge, there have not been any upscaled applications of concrete with MRA and low cement conten

Introduction to building information modeling (BIM) in buildings and engineering infrastructure

La actual exigencia técnica del manejo de programas de diseño en el ámbito de la Ingeniería Civil y la Edificación lleva a plantear de forma indispensable la necesidad de formación de los futuros profesionales en la metodología BIM (Building Information Modeling). Mediante el presente Proyecto de Innovación Docente se ha desarrollado un modelo de implantación de esta metodología adaptándolo al programa actual de cada asignatura y a las competencias exigidas. La metodología y conocimientos teóricos y prácticos de las herramientas BIM han sido impartidos a 40 alumnos aproximadamente pertenecientes a tres títulos y niveles universitarios diferentes. Los resultados obtenidos muestran una evaluación satisfactoria por parte de los alumnos, respondiendo mediante la enseñanza de nuevas herramientas de diseño a las crecientes necesidades profesionales y enriqueciendo las habilidades de los estudiantes universitarios.The current technical requirement of the management of design programs in the Civil Engineering and Building sector leads to raise the need for training of future professionals in BIM technologies (Building Information Modeling). Through this Teaching Innovation Project, a model for the implementation of this tool has been developed. The tool has been adapted into the current educational program of each subject and to the required competences. The methodology and theoretical and practical knowledge of the BIM tool have been taught to approximately 40 students belonging to three different university degrees and levels. The results obtained show a satisfactory evaluation by the students. The growing professional needs are met, and the skills of university students are enriched by teaching new design tools

Actions for novel teacher training: design and implementation of learning activities and resources on LMS support

El presente artículo describe el desarrollo de un Proyecto formativo para la implementación de actividades y recursos de aprendizaje en la plataforma UCO-Moodle por parte de profesorado novel, bajo tutela y coordinación de profesorado con experiencia previa contrastada. Se trata de un trabajo multidisciplinar donde las acciones se han ejecutado para ocho asignaturas de cuatro Áreas de conocimiento. El impacto de las innovaciones introducidas en varias asignaturas, afectó a más de 500 alumnos pertenecientes a seis títulos de grado de la Universidad de Córdoba. El trabajo realizado se completó con una evaluación de satisfacción por parte de los alumnos de los nuevos recursos de aprendizaje así como la autoevaluación del profesorado novel sobre la experiencia desarrollada.This article describes a project for the implementation of learning activities and resources in the UCO-Moodle platform by training teachers has been developed under the supervision and coordination of senior teaching staff with proven previous experience. It is a multidisciplinary work where the actions have been executed for eight different subjects in four Areas of knowledge. The impact of the learning activities introduced in different subjects was extended to more than 500 students belonging to six undergraduate degrees from the University of Cordoba. The experience has included an evaluation of students' satisfaction with the new learning resources as well as the self-assessment of the new teaching staff on the executed actions