scholarly journals Influence of Gradation on Resilient Modulus of High Plasticity Soil-Gravel Mixture

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Chuang Liu ◽  
Tian-Zeng Ren ◽  
Rui Zhang ◽  
Qian-Feng Gao ◽  
Jian-Long Zheng
Keyword(s):  
Resilient Modulus ◽  
Economic Benefits ◽  
Construction And Demolition Waste ◽  
Triaxial Tests ◽  
High Plasticity ◽  
Demolition Waste ◽  
Gravel Content ◽  
Coarse Aggregates ◽  
Mixing Method ◽  
Skeleton Structure

Because of low resilient modulus, high plasticity soil is often not allowed to fill road subgrades and is discarded as construction and demolition waste (CDW). To make use of the CDW, this study explored the possibility of improving high plasticity soil with gravel and examined the effect of gravel gradation on the resilient modulus of the soil-gravel mixture. A series of dynamic triaxial tests, tests of voids in coarse aggregate, and X-ray CT scans were carried out on high plasticity soil-gravel mixtures of different gravel contents and gravel gradation types. The test results show that there is a critical gravel content, that is, 44.1%. When the gravel content is less than 44.1%, the mixture shows a dense suspended structure and its modulus increases slowly with increasing gravel content. When the gravel content is greater than 44.1%, the mixture exhibits a dense skeleton structure and the modulus increases rapidly as the gravel content rises. Moreover, as the gravel gradation tends to the lower type, coarse aggregates increase in quantity and contact each other to form a dense skeleton; thus, the modulus increases accordingly. As the gravel gradation approaches the upper type, coarse aggregates decrease in quantity and tend to suspend in the soil, so the modulus decreases. With the increase in contact number, the skeleton structure is continuously improved, and thus the modulus is enhanced progressively. The results indicate that the gravel mixing method with a gravel content of 40%–45% can effectively improve high plasticity soil and shows great environmental and economic benefits.

scholarly journals Statistical and Reliability Study on Shear Strength of Recycled Coarse Aggregate Reinforced Concrete Beams

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3321
Author(s):  
Hyunjin Ju ◽  
Meirzhan Yerzhanov ◽  
Alina Serik ◽  
Deuckhang Lee ◽  
Jong R. Kim
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Construction Material ◽  
Safety Margin ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Rc Structures ◽  
Coarse Aggregates

The consumption of structural concrete in the construction industry is rapidly growing, and concrete will remain the main construction material for increasing urbanization all over the world in the near future. Meanwhile, construction and demolition waste from concrete structures is also leading to a significant environmental problem. Therefore, a proper sustainable solution is needed to address this environmental concern. One of the solutions can be using recycled coarse aggregates (RCA) in reinforced concrete (RC) structures. Extensive research has been conducted in this area in recent years. However, the usage of RCA concrete in the industry is still limited due to the absence of structural regulations appropriate to the RCA concrete. This study addresses a safety margin of RCA concrete beams in terms of shear capacity which is comparable to natural coarse aggregates (NCA) concrete beams. To this end, a database for reinforced concrete beams made of recycled coarse aggregates with and without shear reinforcement was established, collecting the shear specimens available from various works in the existing literature. The database was used to statistically identify the strength margin between RCA and NCA concrete beams and to calculate its safety margin based on reliability analysis. Moreover, a comparability study of RCA beams was conducted with its control specimens and with a database for conventional RC beams.

The Application of Soy Biodiesel in Bituminous Priming of Soil-Aggregate Layers of Low Traffic Volume Roads in the State of Ceara, Brazil

2014 ◽  
Vol 875-877 ◽  
pp. 115-125
Author(s):  
Bruno Tiago Angelo da Silva ◽  
Suelly Helena de Araújo Barroso
Keyword(s):  
Resilient Modulus ◽  
Asphalt Mixture ◽  
Soil Aggregate ◽  
Traffic Volume ◽  
The State ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Compaction Energy ◽  
Materials Used ◽  
Low Traffic

This work investigates the potential of penetration, in terms of bituminous prime coat, of an asphalt mixture produced adding Soy Biodiesel [BIO] to the Asphalt Cement [AC] to be used in low traffic volume roads in the state of Ceara, Brazil. The main objective of this investigation was finding a less polluting alternative, by replacing kerosene, usually applied as diluent of AC in the traditional mixture CM-30. Therefore, a comparative study was made between the traditional binder [CM-30] and the proposed mixture [40% of Soy Biodiesel and 60% of AC 50/70], named as AC/BIO. Both tested binders were used in specimens made by the stabilization of a sandy soil, adding 50% and 60% of construction and demolition waste, resulting in two different soil-aggregate mixtures. The research considered some factors that influence the extent of penetration of the prime coat: moisture content of the base, type and volume of binder used and compaction energy. The characterization of the materials used in this research included tests such as the gradation of the aggregates, CBR and Resilient Modulus of the mixtures soil/aggregate, viscosity Saybolt-Furol and penetration of the binders (traditional and AC/BIO) in the samples of soil/aggregate. The results showed that the penetration potential of the AC/BIO mixture was similar to the CM-30 keeping the technical viability.

scholarly journals Compressive Strength of Concrete with Construction and Demolition Waste and m-SAND using Additives

2019 ◽  
Vol 8 (2S10) ◽  
pp. 935-937
Keyword(s):  
Compressive Strength ◽  
Green Building ◽  
Cost Effective ◽  
Construction And Demolition Waste ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Demolition Waste ◽  
Rapid Urbanization ◽  
Manufactured Sand ◽  
Coarse Aggregates

Construction and Demolition wastes(C&D wastes) are generated in all cities of the world due to rapid urbanization. Disposing C & D waste these days is a costly affair, and raises environmental issues. Hence an attempt is made to reuse the demolished concrete as a partial replacement of natural coarse aggregates. Also due to ban of sand mining by local authorities, the cost of natural fine aggregate is very high and itself becoming a scarce material. Hence crushed stone aggregates called manufactured sand (m sand) is used, totally replacing natural fine aggregates. This concept is found to be cost effective, minimizes disposal of C & D wastes, and leads towards Green Building Concepts. Compression test on M40 concrete cubes of size 150mmx150mmx150mm are conducted at end of 7 days and 28days. Mix design for M40 concrete is made in accordance to IS: 10262-2019 with water cement ratio of 0.45 using 53 Grade Ordinary Portland cement. Superplasticizer (LIQUIFIX) is used to enhance workability. Nano Silica (NS)(1.5% by weight of cement),Wollastonite powder(WP)(10%by weight of cement) and Basalt fibres(BF)(1% by weight of cement) are added as additives. It is observed, that compressive strength of 7 days and 28 days cured samples is 25% more with the addition of all three additives compared to samples without additives. Hence the loss of compressive strength obtained by using demolished concrete as aggregates and m sand in concrete is regained with the addition of additives.

Efficient supervision strategy for illegal dumping of construction and demolition waste: A networked game theory decision-making model

2021 ◽  
pp. 0734242X2110320
Author(s):  
Chenyu Liu ◽  
Chunxiang Hua ◽  
Jianguo Chen
Keyword(s):  
Decision Making ◽  
Forest Fires ◽  
Evolutionary Game ◽  
Small World ◽  
Economic Benefits ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Illegal Dumping ◽  
Government Supervision ◽  
The Government

While the construction industry has brought substantial economic benefits to society, it has also generated substantial construction and demolition waste (CDW). Illegal dumping, which refers to dumping CDW in an unauthorized non-filling location, has become widespread in many countries and regions. Illegally dumping CDW destroys the environment, causing groundwater pollution and forest fires and causing significant economic impacts. However, there is a lack of research on the decision-making behaviours and logical rules of the main participants, construction contractors and the government in the illegal CDW dumping process. This paper constructs an evolutionary game model on a small-world network considering government supervision to portray the decision-making behaviours of illegal dumping participants and conducts a numerical simulation based on empirical equations to propose an effective supervision strategy for the government to manage illegal CDW dumping efficiently. It is found that the illegal dumping behaviours of contractors are mainly affected by the intensity of government supervision, the cost of fines and the income of illegal dumping; while for government, a supervision strategy is found to be necessary, and a supervision intensity of approximately 0.7 is the optimal supervision probability given supervision efficiency. Notably, under a low-level supervision probability, increasing the penalty alone does not curb illegal dumping, and a certain degree of supervision must be maintained. The results show that in addition to setting fines for illegal dumping, the government must enforce a certain level of supervision and purify the market environment to steadily reduce illegal dumping.

scholarly journals Evaluation of the strength of concretes produced with recycled CDW aggregates originating from a housing project located in Pernambuco, Brazil

2021 ◽  
Vol 10 (5) ◽  
pp. e6610514583
Author(s):  
Renan Gustavo Pacheco Soares ◽  
Gustavo Gutierrez de Oliveira Rodrigues ◽  
Emylle Kerolayne Palmeira de Andrade ◽  
Carla Renata Xavier Pacheco ◽  
Lyneker Souza de Moura ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Urban Areas ◽  
Good Alternative ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Demolition Waste ◽  
Coarse Aggregates ◽  
Construction Techniques ◽  
Three Samples ◽  
Hardened State

In view of the improvement of construction techniques and technological innovations, civil construction still faces numerous problems. Uncontrolled exploitation of natural resources has caused major environmental impacts, in addition to the generation and accumulation of debris in urban areas. Thus, recycling appears as a sustainable alternative to reduce the accumulation of this waste. As an option, there is the use of Recycled Aggregates, obtained through Construction and Demolition Waste (CDW). In this sense, the present study aimed to analyze the feasibility of using the CDW through its application in the production of recycled coarse aggregates in concrete. For the tests, the coarse aggregate was replaced in the proportions of 0 (reference line), 10, 20, 30, 40, 50 and 100%, with three samples for each line and age. The dosage of the strokes followed the parameters established by the IPT / EPUSP method. The concretes were analyzed for compressive strength at 7, 14 and 28 days and the samples were evaluated for properties in an anhydrous, fresh and hardened state. The data collected in the tests were tabulated and analyzed for the degree of addition and its correlation with the characteristic resistance. The results allowed to conclude that the use of the residue in the form of aggregate for the concrete, in the proportions of 10% and 20%, does not affect the compressive strength, making it a good alternative.

scholarly journals An Examination of the Development of the Construction and Demolition Waste-Related Regulations in Turkey

2019 ◽  
Vol 50 (2) ◽  
pp. 169-177
Author(s):  
Burcu Salgın
Keyword(s):  
Occupational Health ◽  
Human Health ◽  
Health And Safety ◽  
Occupational Health And Safety ◽  
Economic Benefits ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Safety Issues ◽  
Draft Regulation ◽  
Health And Safety Issues

In order to manage construction and demolition (C&D) waste, which is harmful to the natural environment and human health, legislation has been introduced throughout the world. In Turkey, the most comprehensive regulation that deals only with C&D waste management (WM), entered into force in 2004. However, changes in the construction sector from 2004 until the present has led to inadequacies in some areas of this regulation. Therefore, a new draft regulation was prepared in 2017. This study is conducted to understand the strengths and weaknesses of the C&D WM regulations, identify the problems, and give recommendations. A three-stage methodology is adopted that includes a literature review, classifying the findings and analysing the relevant literature under the five main topics (the objective and the extent of the regulations, occupational health and safety issues, planning the demolition, collecting and transporting the produced waste, and establishing and operating the recovery plants). The findings show that the draft regulation contains arrangements for Turkey’s current conditions. The terms of the draft regulation have brought more importance to environmental and human health, and occupational health and safety issues. However, only asbestos has been highlighted in the draft regulation as a hazardous waste. The draft regulation includes a limited arrangement regarding the waste produced in the case of refurbishment projects. It is assumed that eliminating the deficiencies in the draft regulation and the enactment of it will be an important step. Thus, environmental and economic benefits for Turkey will follow.

scholarly journals Stone Matrix Asphalt (SMA) with Construction Waste and Curauá Fiber (Ananas erectifolius)

2020 ◽  
Vol 9 (8) ◽  
pp. e410985227
Author(s):  
Patrícia de Magalhães Aragão Valença ◽  
Anne Karollynne Castro Monteiro ◽  
Cláudia Ávila Barbosa ◽  
Carlos Eduardo Neves de Castro ◽  
Consuelo Alves da Frota
Keyword(s):  
Void Ratio ◽  
Coarse Aggregate ◽  
Resilient Modulus ◽  
Construction And Demolition Waste ◽  
Fine Aggregate ◽  
Mechanical Parameters ◽  
Demolition Waste ◽  
Stone Matrix Asphalt ◽  
Final Composition ◽  
Curauá Fiber

The SMA mixtures are characterized by a high void ratio, which favors binder draindown. In order to avoid this effect, fibers are added to the mixture, which in this case came from Curauá da Amazônia (Ananas erectifolius). The final composition studied resulted in 75% coarse aggregate, 15% fine aggregate, 10% filler, 0.3% of the Curauá fiber residue, and CAP contents equal to 6.50% and 6.88% for the formulations with SMA-Crushed Stone (reference) and SMA-construction and demolition waste (alternative), respectively. The results showed for the Tensile Strength that the composites with CDW reached higher results. The Resilient Modulus values presented small variations for the set of compositions in all loading levels at a temperature of 25°C. However, at a temperature of 40°C, the aforementioned parameter presented decreases in both researched formulations. In general, at all levels examined, higher results were observed for the alternative mixture (SMA-CDW). It is noteworthy the highest results of this parameter when comparing the compositions with the Curauá fiber residue and the formulations mentioned in the literature, with the presence of other types of fibers. Regarding the increase in temperature, there was a decrease in results for both mechanical parameters (TS, DM), but with lower losses for the SMA-RCD composition.

scholarly journals Mechanical characterization of concretes produced with construction and demolition waste

2020 ◽  
Vol 9 (1) ◽  
pp. e56911597
Author(s):  
Pedro Valle Salles ◽  
Thiago Marques Viana ◽  
Camila Lacerda Gomes ◽  
Flávia Cristina Silveira Braga ◽  
Flávia Spitale Jacques Poggiali ◽  
...  
Keyword(s):  
Mechanical Characterization ◽  
Construction And Demolition Waste ◽  
Partial Replacement ◽  
The European Union ◽  
Demolition Waste ◽  
Environmental Liabilities ◽  
Mixing Method ◽  
Natural Aggregates ◽  
Good Workability

The construction industry is responsible for the generation of large volumes of waste, known as construction and demolition waste (CDW). Around the world, millions of tons of these wastes are generated annually, which often become important environmental liabilities. The situation gets worse as the sector develops. In Europe, only 15 of the 27 countries in the European Union annually produce around 180 million tonnes of CDW, in Brazil, the data about this indicates that in 2014 the municipalities collected about 45 million tons of CDW, quantity 4.1% higher than in 2013. In this scenario, the present study aims to evaluate the partial replacement of natural aggregates by CDW (aggregates of concrete waste) in the production of concretes. In this sense, the effects of this substitution on the workability and mechanical characteristics of the concretes produced, as well as the influence of the mixing method and the percentage of superplasticizer additive on the same characteristics were evaluated. The methodology basically consists in the production of seven different traits, which are references and different combinations of mixing method, aggregate substitutions and superplasticizer percentages. Specimens of these traces were molded for mechanical characterization. Workability parameters were also evaluated. It is concluded that the workability is strongly affected by the addition of CDW, but a good workability can be obtained with the use of superplasticizer additives. The mixing method did not change the results obtained for this property. The results also indicate that the compressive and tensile strengths are not negatively affected by the substitution of aggregates, as well as being not significantly affected by the presence of the percentages of superplasticizer used, nor by the mixing methods.

scholarly journals Construction Waste Audit in the Framework of Sustainable Waste Management in Construction Projects - Case Study

2020 ◽  
Author(s):  
Marcela Spišáková ◽  
Peter Mésároš ◽  
Tomáš Mandičák
Keyword(s):  
Waste Management ◽  
Waste Disposal ◽  
Construction Projects ◽  
Economic Benefits ◽  
Construction And Demolition Waste ◽  
Transport Costs ◽  
Demolition Waste ◽  
Construction Waste ◽  
Building Information

The issue of sustainability has long been the subject of interest of the architecture engineering and construction sector. All three aspects of sustainability - economic, environmental and social - can be affected through appropriate construction waste management. Construction and demolition waste (CDW) is one of the largest worldwide waste streams, therefore it is given great attention by all stakeholders (investors, contractors, authorities, etc.). Researches have shown that one of the main barriers to insufficiency CDW recovery is inadequate policies and legal frameworks to manage CDW. It is also one of the EU's environmental priorities. Aim of the article is to confirm the economic potential of construction and demolition waste audit processing through case study. A pre-demolition waste audit has been processed for unused building of shopping center in the town Snina in Slovakia. Subsequently, a comparison of economic parameters (waste disposal costs and transport costs) of recommended CDW management was performed. This comparison confirmed the economic benefits of environmentally friendly construction waste management methods according to the waste audit results, which will also increase the sustainability of construction projects. In addition, the cost parameters of selected waste disposal methods could be another dimension of building information modelling.

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