Construction Waste Materials Research Articles

Recycled construction and demolition waste material: a cost–benefit analysis under uncertainty

PurposeConstruction and demolition waste (CDW) continuously causes environmental and social problems. These formidable challenges lead to sustainable issues and are an increasingly urgent issue worldwide. Prior studies have neglected to link the triple bottom line (TBL) to a reliable estimation or empirical model for estimating CDW production performance and lack empirical sensitivity analysis in profit maximization. This study proposes an attribute analysis to build a cost–benefit analysis (CBA) to obtain profit maximization.Design/methodology/approachThis study uses fuzzy set theory to develop a cost and benefit analysis (CBA) model to assess the sensitivity analysis in terms of its performance on addressing the environmental, economic and social aspects. The model is used to weigh the sum of benefits such as financial gain and total costs of actions taken to mitigate the negative impacts.FindingsBased on the sensitivity analysis conducted, the environmental, economic and social mean scales were significantly changed, i.e. increased, and profits increased drastically. The results provide an insight into environmental legislation compliance, environmental investment and environmental impact as the cause attributes for the CDW recycling profit increase. The results prove that sensitivity analysis is viable to infer that a sustainable production performance can achieve more revenue and profit through an adequate selection of attributes regarding the TBL aspects to address the firm's uncertainty problem in multiple criteria analysis.Originality/valueThis study builds a CBA model to maximize profits for recycled CDW material by linking of environmental, economic and societal aspects for recycled CDW assessments. It considers a sustainability structure with criteria based on TBL aspects to assess production performance to realize the Sustainable Development Goals and presents fuzzy set theory and sensitivity analysis to solve the uncertainty problem in the construction industry.

Evaluating the creep characteristics of recycled construction waste materials under saturated and dry condition

The creep deformation characteristics of recycled construction and demolition waste (CDW) filler are important factors affecting its road performance. In this paper, a series of laboratory tests are carried out on CDW filler, including gradation test, compaction test, California bearing ratio (CBR) test, and creep test, and the road performance of different ratios of recycled CDW filler is systematically studied. The mechanical properties of different ratios of CDW materials can meet the requirements of subgrade filler in the specification. Through the creep test, it can be seen that the elastic-plastic deformation speed of CDW material is fast and the duration is short. The creep deformation stage is opposite. Combined with the theoretical analysis, it is found that the t/e-t curve under each stress level has a good linear relationship. The relationship between strain and time is hyperbolic, and the relationship between parameters A, B, and load is a power function. The creep process belongs to attenuation creep, which conforms to the Kelvin model.

Preliminary Evaluation of Cement Mortars Containing Waste Silt Optimized with the Design of Experiments Method.

Every year, up to 3 billion tons of non-renewable natural aggregates are demanded by the construction sector and approximately 623 million tons of waste (mining and quarrying) was produced in 2018. Global efforts have been made to reduce the number of virgin aggregates used for construction and infrastructure sectors. According to the revised waste framework directive in Europe, recycling at least 70% of construction and demolition waste materials by 2020 was obligatory for all member states. Nonetheless, quarries must work at full capacity to keep up with the demands, which has made quarry/mining waste management an important aspect during the past decades. Amongst the various recycling methods, quarry waste can be included in cement mortar mixtures. Thus, the current research focuses on producing cement mortars by partially substituting natural sand with the waste silt obtained from the limestone aggregate production in S.A.P.A.B.A. s.r.l. (Italy). A Design of Experiments (DOE) method is proposed to define the optimum mix design, aiming to include waste silt in cement mortar mixtures without affecting the final performance. Three cement mortar beams were produced and tested for each of the 49 randomized mixtures defined by the DOE method. The obtained results validate the design approach and suggest the possibility of substituting up to 20% of natural sand with waste silt in cement mortar mixtures.

Ecotoxicity and Essential Properties of Fine-Recycled Aggregate.

This article deals with the possibility of utilization of secondary-raw materials as a natural sand replacement in concrete. Four types of waste construction materials were examined—recycled aggregate from four different sources. The natural aggregate was examined as well as used as the reference sample. All the samples were tested to evaluate the water absorption, particle size distribution, and particle density. The basic chemical reactions in the view of ecotoxicology are investigated and measured based on Czech standards. Chemical analysis, Lemna growth inhibition test, freshwater algae, daphnia acute, and mustard germination toxicity test were made and discussed in this paper. Based on the physical and geometrical properties and ecotoxicology of examined waste materials, this work evaluated them as suitable for utilization in concrete as a sand replacement.

Reduction of the Cement Content by Incorporation of Fine Recycled Aggregates from Construction and Demolition Waste in Rendering Mortars

The construction sector is responsible for one third of the total wastes produced in the EU. Finding solutions for the reuse or recycling of these wastes is one of the major environmental concerns of modern times. The replacement of sand or cement in specific construction materials, such as concrete or mortars, is a possible solution for these wastes’ management. By using construction and demolition wastes in construction materials, namely on buildings, the cycle of circular economy is closed, increasing the life cycle of the wastes in the same sector. In this research, a reduction of cement content in rendering mortars is analysed. This reduction is achieved by a decrease of the cement/aggregate ratio simultaneously with the incorporation of very fine recycled aggregate from construction and demolition waste. Two recycled aggregates were studied: recycled concrete aggregate (RCA) and mixed recycled aggregate (MRA). The fresh and hardened state properties of the mortars were analysed. Several tests were carried out to evaluate the mortars’ performance, such as mechanical strength tests, water absorption tests, drying tests and shrinkage. It was noticed that the incorporation of RCA led to a better behaviour than in the reference mortar, in terms of mechanical strengths and protection against water.

Sustainable utilization of industrial wastes for the cleaner production of ferrocement structures: A comprehensive review

Creative development of ferrocement technology in the construction industry has enhanced dynamically due to its faster construction, lighter weight, higher strength, durability and economical advantages than the reinforced concrete structures. The use of smaller diameter closely spaced mesh layers which is uniformly distributed throughout the cross section improved the moment of resistance, deflection and ductility of the ferrocement members. To achieve the environmental friendliness and sustainability in the durable ferrocement technology, this paper aims to provide a comprehensive implication reviewed from the previous research works carried out to explore the application of industrial waste materials in the ferrocement construction. Influence of various industrial waste materials on the behaviour of both mortar and meshing reinforcement were discussed separately. The optimum level replacement, effect on the structural behaviour and the suitability in the various environmental conditions were inferred. For instance, Ground Granulated Blast furnace Slag (GGBS) could be utilized as a binder at the maximum of 50% by weight, where as the use of metakaolin in ferrocement construction is optimum at 15% by weight as further addition caused the undesirable effect on the mechanical properties due to the delay in hydration process and inefficient filler effect. Grain size modified nano industrial wastes like nano silica and nano fly ash resulted in improved mechanical and micro structural behaviour of ferrocement products due to its nano filling effect. The use of nano fly ash was found to be successful as nano binder to the maximum of 10% which is not possible in case of other costlier nano materials like nano silica, alumina, titanium oxide, etc. The major issues of corrosion and chemical attack in ferrocement mesh were easily solved by the implementation of high molar geopolymer mortar which also resulted in cleaner and greener production of ferrocement products.

PHYSICAL PROPERTIES AND SHEAR STRENGTH OF BOILER SLAG

This study is about the determination of the physical and engineering properties of boiler slag. The boiler slag is a by-product that is obtained from the Tanjung Bin power plant. The source of reference for the use of boiler slag is minimal for this type of applications. However, this is an environmental suggestion to utilise the disposed of by-product from the ash pond. In this study, the properties of boiler slag are determined, such as the specific gravity, particle size distribution and shear strength. The specific gravity of boiler slag obtained was found to be 2.45, falls in the range provided by User Guidelines for Waste and By-product Materials in Pavement Construction by Federal Highway Administration. While, the shear strength for three samples tested were 73.78kN, 141.2kPa, and 285.9kPa. The internal friction angle of the sample obtained by the plotted graph of shear stress vs normal stress is 55°. The result obtained was analysed and concluded to acknowledge the capability of boiler slag as a construction material to be used in construction, mainly in pavement industries.

Properties of alkali-activated roller compacted concretes produced from waste aggregates

The energy consumption and the release of carbon dioxide during cement production require the search for alternative building materials. There is an increasing need for more environmentally friendly, more economical, durable and high-strength materials. Studies on recycling of waste materials in construction contribute to meeting this need. In this study, a new material that allows reuse of wastes was produced using known materials and techniques. Alkali-activated roller compacted concrete [AARCC] was produced with recycled coarse aggregates and the mechanical properties of this material were investigated. In this experimental study, the objective was to produce an alternative construction material composed of waste or by-products. Ground granulated blast furnace slag [GGBFS] was activated with a sodium silicate [Na2SiO3] and 10 M sodium hydroxide [NaOH] solution. The Na2SiO3 / NaOH ratio was 2.5 in the activator solution. The coarse aggregates were obtained from roller compacted concrete (RCC) wastes and an environmentally friendly material was produced without using any cement. As a roller compacted concrete is produced with a very dry consistency compared to conventional concrete, the amount of activator used is low, which provides environmental and economic benefits. The compressive strengths of the cube RCC specimens were determined at the ages of 7 and 28 days. Using the mix proportions designed in this study, it was found that the compressive strengths of alkali-activated RCCs were higher than roller compacted Portland cement concrete having high dosage of cement. Unit mass, total water absorption, ultrasonic pulse velocity [UPV], and modulus of elasticity of alkali-activated RCCs were also determined.

Analysis of the triggering mechanism of landslide in the village Podi, Montenegro

Frequent landslides in the flysch zones along the Adriatic coast commonly develop on the contact between the sound flysch and Quaternary sediments. The reason for this is most often the increased pore pressure and degradation of material due to inadequately regulated surface and groundwater. A case of one such landslide in the south-western part of Montenegro is presented in this paper. The disposal of construction waste materials above the location of the village Podi was followed by the occurrence of a landslide which affected 3.5 ha of slope and damaged 27 houses in the village. In the course of legal proceedings initiated against the contractor, a question arose of whether the deposited material could have triggered the landslide. Response to this complex question required a multidisciplinary approach, including also a numerical parametric analysis. The results of such analysis indicated that the improper depositing of material above the village induced the landslide activation for two reasons: an increase in shear stress and a change in the natural groundwater regime, which in turn affected elevation in the pore water pressure. Numerical analyses indicated that with a moderate water table rising, the factor of safety decreased by some 20%, which in case of an already conditionally stable slope is sufficient to initiate the terrain movement and formation of a landslide on a wider area.

Study on Recycling and Reuse of Waste Materials in Building Industry

Treatment of rapid growing large quantity of waste materials has been recognized as a major issue in the modern construction industry. It has great impact on both the efficiency and environment of construction projects. Recycling reduces original-resource production so that the environmental impact can be reduced. Simultaneously, recycling brings benefits to the economy. The United States has done a lot in recycling and reuse in building industry, but there are still some insufficient in this area. While China keeps more and more attention in recycling and will try hard to improve the proportion and widen the measures of recycling. From the perspective of these two counties, this paper describes the current state of recycling and reuse of waste materials in the building industry, analyzes the benefits, and puts forward the measures for reuse of waste materials. The paper indicates that the recycling and reuse of waste materials has multiple benefits. Waste materials can be used directly or reused through simple or complex processing, and they can be reused for the same purpose or for a different purpose from the original one. More efforts should be made in recycling and reuse of the construction waste materials.

The classification of construction waste material using a deep convolutional neural network

The management of Construction and Demolition Waste (C&DW) is complex and adds significantly to the overall life cycle cost of projects. On site waste sorting using technologies that automatically identify different materials has the potential to assist in classifying C&DW and reduce costs. The aim of this research was to design and describe a deep convolutional neural network (CNN) to identify 7 typical C&DW classifications (both single and mixed disposal) using digital images of waste deposited in a construction site bin (artefact). This approach emulated authentic construction site scenarios where on-site sorting is difficult. A novel design science methodology was used. The experiments delivered 94% accuracy, classifying both single and mixed C&DW. This accuracy is important on projects where on-site sorting is attempted, as in practice bin contamination escalates project costs and reduces C&DW diversion from landfill. To illustrate potential of the research the innovative artefact is incorporated within a hypothetical case study describing its use in a circular C&DW business model.

A study on the suitability of solid waste materials in pavement construction: A review

This paper describes the various ways in which huge volumes of waste formed from urban and semi-urban areas can be optimally reutilized as an additive in the construction of bituminous pavements. It shows that different waste materials like scrap tyres, plastic wastes, glass, coal waste, fly ash, concrete waste, wood waste, etc. can be effectively reused in bituminous pavement construction. In countries like India, waste derived from various sources is usually incinerated, open burned, dumped into water bodies, disposed through landfills or ground, and discharged to sewers. This shows the potential of waste being used as a construction material in pavement development in developing nations like India where consumption is more and the availability of space for disposal is less. Moreover, the need for effective energy utilization and global climate change have made it mandatory to reduce pollution and increase recycling and re-use. Hence, to satisfy environmental norms, such practices need to be introduced into civil engineering situations. This work evaluates the various application of solid waste in sustainable pavement engineering and reviews the existing works on the re-utilization of solid wastes as road construction material and their sustainability. Life cycle assesement (LCA) was conducted to evaluate the environmental impact of solid waste as a construction material. The principal findings of this study reveal that solid waste obtained from various sources could be effectively incorporated into construction materials in the forms of aggregate, reinforcement fiber, filler material, additive etc. In summary, the study guides us in adopting stable and eco-friendly choices of converting the wastes into superior environmentally friendly road construction materials. In addition to being a lesser burden to the environment, this practice provides a satisfactory enhancement in the strength and durability of the pavements and also helps reduce energy and overall cost thereby proving to be a very useful and effective choice for all pavement related works.

Evaluation of volumetric performance of asphalt mixtures containing recycled construction aggregate (RCA)

ABSTRACT High rate of construction and demolition waste materials results in a large amount of stockpiled waste materials. Pavement industry is now considering a sustainable approach for asphalt mixture design incorporating certain waste materials. This research investigates the feasibility of substitution of virgin aggregates in asphalt mixes with recycled construction aggregates (RCA) obtained from the construction and demolition sector. A preliminary experimental study including determination of flakiness index, particle shape, wet/dry strength variation, water absorption rate, particle density, crushing value, deleterious material and weak particles was conducted on blends of RCA and virgin aggregates to evaluate the engineering properties of aggregate blends. Different asphalt mixes incorporating RCA at different rates were prepared and evaluated using a gyratory compaction. The results of the regression analysis showed that the asphalt mixtures containing 20% to 22% RCA provide comparable volumetric properties as the control sample, while mixes with higher RCA substitutions achieved higher air voids, and lower voids in the mineral aggregate (VMA), voids filled with asphalt (VFA) and binder film index (BFI). The results of this study suggested a feasible use of RCA for partial aggregate replacement in hot mix asphalt (HMA).

Feasibility of urban waste for constructing Technosols for plant growth

An alternative for sustainable urban development is to revegetate cities with the construction of planters as well as to recover degraded sites. The objective of this work was to characterize urban waste materials produced in Mexico City and to evaluate their potential for constructing Technosols for plant growth, as an alternative to use in revegetating the city without affecting natural landscapes. Construction and demolition waste materials amended with different application rates of compost made out of gardening wastes from Mexico City green areas were tested. Nine mixtures were prepared; three based on concrete, three based on demolition waste and three based on excavation waste. Changes on physical, chemical and physicochemical properties of these mixtures, namely nutrient contents, water retention and aeration capacity, were monitored in a twelve-month experiment. The mineralogy and the risk regarding the release of heavy metals and trace elements were also evaluated in the soluble fraction. The constructed Technosols were appropriate, to a greater or lesser extent, for tomato plant growth. Soil pH and soil electrical conductivity (EC) were the main factors defining their suitability; both parameters changed over time due to the washing of salts. The particle size of the mineral materials as well as the application rates of compost used in the construction of the Technosols resulted in adequate water holding capacity and soil aeration for plant growth. The type of parental materials defined the majority of the Technosol characteristics as well as their ability to function as a plant support. The concentrations of readily available heavy and trace metals were not a limitation for plant growth. However, potential co-transport of these elements with soluble organic matter should be considered in further research.

Mechanical and durability behavior of recycled aggregate concrete made with different kinds of wastewater

The reuse of industrial wastewater and the recycling of construction and demolition waste material produced by the construction industry will lead to a sustainable environment by reducing the exploitation of the new natural resources and the waste deposit areas. The present study endeavors to investigate the mechanical and durability performance of recycled aggregate concrete (RAC) made with five different kinds of wastewater taken from domestic sewerage, fertilizer factory, textile factory, sugar factory, and service station. The potable water was completely replaced with each kind of wastewater for the mixing of concrete to examine its effect on compressive strength (CS) and split tensile strength (STS), water absorption (WA), chloride penetration (CP), and resistance against sulfuric acid attack of RAC at various testing days. The results show that using the wastewater taken from the textile factory in the production of RAC presents the maximum CS (32.2 MPa) and STS (3 MPa) that were 19% and 16% higher than that of the RAC made with potable water. The use of wastewater taken from domestic sewerage for the mixing of RAC presented the highest WA (13.88%). The usage of wastewater taken from the fertilizer factory in the production of RAC depicted the maximum mass loss (19.62% at 120 days of testing) due to an attack of 4% H2SO4 and the highest CP (16.49 mm at 28 days of testing). The statistical analysis depicted a considerable difference among the CS and CP of RAC mixes while no considerable difference was depicted by the statistical tests for the WA, STS, and acid attack for various RAC mixes.

EXTENDED TRIPLE BOTTOM LINE BASED EVALUATION OF REVERSE LOGISTICS OPTIONS FOR CONSTRUCTION WASTE MATERIAL

The construction sector not only plays a significant role in the economic development of a country but also generates considerable construction waste. Treatment of such waste is essential to avoid loss of potentially recoverable material, minimize environmental pollution, reduce monetary losses, and other related hazards. Reverse logistics concept gains popularity due to its material recovery aspect, therefore considered a waste treatment option. However, the selection of the most appropriate treatment strategy requires a critical analysis of various factors. In the past, firstly, technical and economic factors were considered mainly before selecting a treatment method, with limited to no consideration given to environmental, social, and political factors, especially in low and middle-income countries. Secondly, the selection of such treatment methods was mostly based on qualitative assessments. To overcome these issues, at first, this study extends the concept of Triple Bottom Line (TBL) by adding two more lines of technical and political aspects and called it as extended TBL (ETBL). Secondly, a quantitative ETBL scoring method is proposed based on a probability-impact approach to help decision-makers select an appropriate reverse logistics option for construction waste material. A list of bottom-line factors was extracted from the comparison of existing practices among different countries. Lastly, suggestions to Hong Kong stakeholders were provided as per ETBL assessment, which will help future decision-making.

A critical literature review on minimization of material wastes in construction projects

Advancement of waste materials has a noteworthy effect at nature. Development of waste materials has a significant impact at the environment. With the requests in forcing essential foundation extends in India, altogether with numerous business and lodging programs, there are huge amount of creation is produced from the development mechanical and industrial zone Hence, the waste generated from the sites must be well dumped. For this, the waste minimization plans is the better way to reduce the waste getting from the sites. Wastage in creation tasks results super monetary and managerial setbacks to owners and contractors.Not simplest the wastage creates these problems; it also adversely impacts the surroundings very badly. These wastes have to be managed in addition to their influences desires to be nicely studied ,as a result we are able to manage the waste technology and powerful utilization may be stepped forward. Whatever the affects over the surroundings and fitness in many cities of India the generation of wastes from the industry is controlled in a terrible manner say no proper planning and management. In this studies planning, discussing the method for the control and effective utilization of waste construction materials can be discussed.

A Review of the Utilisation of Recycled Waste Material as an Alternative Modifier in Asphalt Mixtures

The possibility of using waste materials in road construction is of great interest as their utilisation may contribute to reducing the problems of hazard and pollution and conserve natural resources. Thus, there is an urgent need to find a sustainable method for using waste materials as a substitute in the standard asphalt binders. There are several concerns about the physical and chemical properties and mechanical performance of asphalt pavements incorporated with waste material in the effort to reduce permanent deformation of the road surface. This review article presents a brief discussion of the asphalt mixtures modified with waste material, and the recycled materials used as a modifier in the asphalt mixture. The present paper summarises the use of crumb rubber, crushed concrete, steel slag, glass fibre and plastic waste in asphalt mixtures. The use of waste materials as a modifier in asphalt mixture resulted in improved asphalt pavement performance. Results advocate that rubberised asphalt mixture with desired properties can be designed as an additive with a friendly environmental approach in construction materials. The researches that adopted the influence of usage, recycle waste material to improve the performance of the asphalt of the road are still limited compared to other construction fields. Doi: 10.28991/cej-2020-SP(EMCE)-05 Full Text: PDF

A New Low-Cost and Reliable Method to Evaluate the Release of Hg0 from Synthetic Materials

Mercury is a toxic and noxious element and is the only metal that naturally occurs as gas. One of the most challenging topics (included in the United Nations Minimata convention) is to understand the adsorption–release processes of manmade materials (e.g., concrete, bricks, tiles, painting). Adsorption of Hg by construction and demolition waste materials has recently been studied, but investigations on how much Hg0 can be released from these products are rather poor. The abandoned mining site of Abbadia San Salvatore (Siena, central Italy) where, for about one century, cinnabar was roasted to produce liquid mercury, is known for the high concentrations of (i) Hg0 in edifices and structures and (ii) total and leachate Hg in synthetic materials. In the present paper, a new, simple and low-cost method to measure the amount of GEM (Gaseous Elemental Mercury) released from anthropic materials (concrete, wall rocks, and tiles) located in the Hg0-rich environments of the former mining site, is proposed. The efficiency of a specific paint that was supposed to act as blocking agent to Hg0 was also tested.

Assessment of Municipal Solid Waste Management Practices in Bahawalpur City, Pakistan

Solid waste management is a global issue persisting in most of the developing countries like Pakistan. Current study briefly appraises the management and practices of municipal solid waste (MSW) in Bahawalpur city. Data were collected from different sources by using an in-depth interview and questionnaire tool. The findings reveal that domestic organic waste accounts for about 35.32% followed by debris, dirt and construction material waste (30.89%). About 273.69 tons solid waste is generated on daily basis whereas only 218.95 tons per day is collected and disposed. The collection rate of MSW varies from 61% to 80% in the city. The service coverage area was about 70%. The total sanitary staff was also very limited (735) as compared to the increasing population and served only 75% population of the Bahawalpur. The equipment and machinery used for MSW collection and disposal operation were also limited and out of fashion which were needed to be replaced. There is no proper landfill for disposal of solid waste which is openly thrown at five dumping sites and burned. This situation further creates many environmental and health issues. Recycling is almost absent in the city and behavior of the inhabitants also adds to an ineffective solid waste management in the city. It is necessary to create awareness among the people about bad effects of improper dumping of solid waste and the need to tackle this problem.