scholarly journals Recycling construction and demolition wastes within hydraulically bound mixtures for road pavements

Author(s):  
Marco Pasetto ◽  
Andrea Baliello ◽  
Giovanni Giacomello ◽  
Emiliano Pasquini

The recycling of Construction and Demolition Waste (CDW) is an actual challenge regarding the construction industry because of the increasing volumes worldwide produced and the related environmental impacts. In this regard, a suitable application can be developed in the road construction field, in particular for the production of hydraulically bound mixtures for road subbase and foundation layers. In this sense, the reuse of CDW can strongly enhance the environmental sustainability of road construction thanks to the achievable savings of natural resources such as the mineral aggregates obtained from quarry operations. Indeed, the utilization of a CDW as aggregate must ensure the production of mixtures with adequate mechanical and environmental characteristics. Therefore, the herein paper presents the results of an experimental characterization aimed at assessing the suitability of CDW for the production of hydraulically bound mixtures for road pavements. In particular, the main mechanical properties of some mixtures including different percentages and gradations of CDW were analysed and compared with the main technical prescriptions and classification criteria indicated by the reference European standards. Basic properties and production processes of the CDW materials were also studied to determine their effects on the optimum binder and water contents of the mixtures. The research clearly demonstrated that the use of a preliminary-washed CDW coarse aggregate was able to enhance the overall structural properties and the water resistance of mixtures.

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1466
Author(s):  
Manuel Cabrera ◽  
Mónica López-Alonso ◽  
Laura Garach ◽  
Javier Alegre ◽  
Javier Ordoñez ◽  
...  

The management of different industrial by-products, such as recycled aggregates from construction and demolition waste and alumina by-products, as well as the reduction of landfill deposits by incorporating these products in a second life cycle, were the focus of this work. The aim of this study was to demonstrate the technical viability of using these waste and by-product as a material for road pavement base layers. For this purpose, a real-scale application was carried out, and the behavior of three types of materials, applied on a section of an experimental road under real vehicle traffic conditions, was studied and compared. Three materials were used in these sections applied in the road sub-bases. First, a control material composed of a type of artificial gravel was used to be compared with the rest of materials; the second material was composed of recycled aggregates, and the third was composed of a mix of recycled aggregates and alumina waste. The results concluded that the effectiveness of the sections built using recycled aggregates and alumina waste was very positive and similar those constructed using natural aggregates.


2020 ◽  
Vol 10 (10) ◽  
pp. 3465 ◽  
Author(s):  
Donato Ciampa ◽  
Raffaele Cioffi ◽  
Francesco Colangelo ◽  
Maurizio Diomedi ◽  
Ilenia Farina ◽  
...  

The growing environmental sensitivity and the reduction of natural resources create, in Italy and other developed countries, an increasing interest in the search for alternative materials to be used in road construction works. In recent years, the problems related to environmental sustainability have made it increasingly difficult to remove natural aggregates from quarries and, at the same time, the regulations for the management of waste dumps are more and more restrictive. For this reason, the use of recycled aggregates is experiencing a continuous increase in the civil construction sector. This paper deals with the study of construction and demolition waste (CDW) in the field of road construction, in particular for the construction of embankment, road subgrades, foundation layers and unbound bases for flexible superstructures. Three different particle size fractions were used to prepare the mixtures: the first having a coarse size and designation 0–63 mm, the second intermediate size with aggregates of 0–31.5 mm grain size and the third with the finest aggregates having a grain size of 0–4 mm. The study was carried out by analyzing three granulometric fractions, verifying the best application for each of them. Subsequently, the mix-design was investigated, operating in compliance with the requirements imposed by UNI 11531-1, EN ISO 14688, EN 13242 and EN 13285. For the unbound layers of subgrade, foundation and base, which require greater resistance to fragmentation, the use of CDW alone has shown some limitations. Therefore, in the experimentation, it was decided to mix the CDW with a granulated slag coming from the steel production in the electric arc furnaces (EAF) and with an additional CDW (0–31.5 mm) coming from the recovery of concrete with slag. EAF granulated slag was used in small quantities, due to its relatively high cost. Four eco-friendly and recycled mixtures were studied, with low economic impact and high environmental sustainability, suitable for the construction of unbound layers of road superstructures.


2019 ◽  
Vol 8 (2S11) ◽  
pp. 2642-2644

The rules and regulations on waste management in the construction and demolition sector are analyzed corresponding to the present scenario of C&DW in India. C&D waste from construction sites has emerged as a significant threat to India because of its severe footprint on the environment. Vast quantities of construction waste will have unfavorable consequences on the surroundings if they are not properly managed. Therefore it is necessary to manage the development of C&DW by the experts within the construction industry. The approach represented is specialized in rules and regulations on waste management so that the environmental impact of construction activities can be minimized.


2011 ◽  
Vol 19 (1) ◽  
pp. 301-301 ◽  
Author(s):  
Sippy K. Chauhan ◽  
Anuradha Shukla ◽  
S. Gangopadhyay ◽  
Sangita Sharma

2018 ◽  
Vol 219 ◽  
pp. 04003 ◽  
Author(s):  
Hubert Anysz ◽  
Krzysztof Kaczorek

The existing system of bids evaluation in the construction industry does not bring the clients the certainty if all placed bids comprise real, achievable prices. Especially in the road construction sector, where the earthworks create significant part of the works, comparing e.g. the price of 1 km of roads often gives misleading results. The paper comprises the complete proposal to modify the scope of information provided by offerors in the public procurements (in the construction industry) allowing the clients to determine easily if the contractors have placed the consistent offers i.e. if the bid prices are not too high and if the lowest bid price is not a dumping price. The Conjugated Triangle Method (CTM) of inconsistent bid detection in construction industry is based on the three inter-related parameters: means of production, time of works, on the value of works. Regardless of the offered price it should match the other two parameters.


2014 ◽  
Vol 600 ◽  
pp. 638-647
Author(s):  
Marina H.S. Santos ◽  
Albéria C. Albuquerque ◽  
Juzélia S. Costa

The project aims to use waste generated in the building construction industry as aggregate for use in artificial artifact of cement, replacing natural aggregate. We investigated the development of mechanical strength of bricks made ​​from construction waste, compared to a reference sample without residue. In this investigation were used mechanical, physical and chemical tests contained in current technical standards. The results demonstrated the viability of this product for masonry sealing. The feasibility of the product, reducing the cost and environmental impact justifies the relevance of the project.


2021 ◽  
Vol 7 (3) ◽  
pp. 594-613
Author(s):  
Pardeep Kumar Oad ◽  
Stephen Kajewski ◽  
Arun Kumar ◽  
Bo Xia

Tender evaluation is the procedure of choosing the best contractor for a particular project from many applicants. Although rational and logical methods can be used for bidding strategies, bid evaluation remains a skill for which an engineer’s verdict is crucial. Contractors commonly witness that tender selection is not an easy job, and the lowest bid does not necessarily win the contract. The tender decision mainly depends on quantifiable measures such as financial costs and paybacks, and qualitative or invisible factors like administrative security accountability, aptitude, and the proficiency of the contractors. Moreover, Bid evaluation is a decision-making procedure that incorporates an extensive criteria range for which the information is not accordingly. Hence, ambiguity linked to such information is not appropriate for this study. This paper aims to evaluate innovation during the bid evaluation process in the road industry. The research results indicate that the private and public sectors in Australia offer innovative products and work methods, given the chance. Therefore, innovation during the bid evaluation process is welcomed and sometimes strongly encouraged. Further, it is important to have strong research in to how to effectively determine value for money in the context of developing suitable and quality roads. Therefore, this research is useful in the context of evaluating factors that help to understand value for money in the road sector in context of bid evaluation process. Doi: 10.28991/cej-2021-03091676 Full Text: PDF


2021 ◽  
Vol 9 (209) ◽  
pp. 1-16
Author(s):  
Samira Mansur Monteiro de Barros

The problems arising from construction and demolition waste have always been in our country. The civil construction industry is the sector that generates the most waste that impacts society and is the one that consumes the most raw materials. As a result, it is necessary and extremely important that there is a sustainable management of construction waste. The irregular dispositions of these residues cause many negative impacts to the environment, since they are often thrown in vacant lots, permanent preservation areas, roads and public places, harming the quality of life of the population. Recycling can generate a significant economic advantage in relation to the final destination both in regular deposits and mainly in relation to the irregular ones that cause so much damage to the environment. This study sought to collect information on the current situation on construction waste. And in order to be developed, the present work used bibliographic research in books, specialized magazines, periodicals, and electronic media. Concluding in the final considerations, in which vital points of the research are presented followed by the stimulations the continuity of the studies and the reflections on the generation of solid residues in the civil construction.


Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1285 ◽  
Author(s):  
Arminda Almeida ◽  
Michela Sergio

Environmental and health concerns have been increasing in the road construction industry. This industry has provided several techniques and a wide range of additives to lower the production temperatures of asphalt mixtures, generating, among others, a new mix type called warm-mix asphalt (WMA). This paper aims to evaluate the potential of the Sasobit REDUX additive to lower the production temperatures of WMA. This additive, which is an alternative to the well-known Sasobit, is completely soluble in bitumen at temperatures above 85 °C while the same temperature for the Sasobit is 115 °C. For that reason, three target compaction temperatures were considered (90, 100 and 110 °C) and both Marshall and compactability tests were carried out. A hot-mix asphalt (HMA) was tested in parallel for comparison. It was concluded that the volumetric properties (air voids content about 4%) and the Marshall properties (stability about 11 kN, flow about 4 mm and Marshall quotient higher than 2 kN/km) of the Sasobit REDUX-WMA were globally satisfactory. In relation to the compactability test, the Sasobit REDUX-WMA mixtures were relatively easier to be compacted compared to the HMA mixture. The three Sasobit REDUX-WMA mixtures (90, 100 and 110 °C) exhibited a very similar compactability (differences lower than 0.4%). Therefore, it seems reasonable to conclude that the Sasobit REDUX has potential to lower WMA production temperatures by 20 °C. A reduction of that magnitude would lead to significant environmental gains.


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