Demolition Waste Generation Research Articles

Динаміка утворення відходів будівництва i знесення у Вінницькій області

Solid industrial waste can be widely used in construction to obtain such valuable materials: as a filler and binder for the production of concrete, dry building mixtures and other building materials, for the production of building materials with protective properties against electromagnetic radiation and static electricity, for the manufacture anode earthing switches, etc. Therefore, the determination of the regression dependence describing the dynamics of the generation of construction and demolition waste in Vinnytsia region to solve the problem of solid industrial waste management is an urgent scientific and technical problem. The aim of the study is to determine, using regression analysis, the dependence that describes the dynamics of construction and demolition waste generation in Vinnytsia region to solve the problem of solid industrial waste management. The study used the method of regression analysis of the results of one-factor experiments and other paired dependencies with the choice of the best type of function from the 16 most common options according to the criterion of the maximum correlation coefficient. The regression was carried out on the basis of linearizing transformations, allowing reducing the nonlinear dependence to linear. The determination of the coefficients of the regression equation was carried out by the least squares method using the developed computer program "RegAnaliz", protected by a certificate of registration of copyright for the work. Adequate regression dependence was obtained that describes the dynamics of construction and demolition waste generation in Vinnytsia region. A graphical relationship has been built that describes the dynamics of construction and demolition waste generation in Vinnytsia region and allows to visually illustrate this dynamics, to show sufficient convergence of theoretical and actual results. It was found that in Vinnytsia region during the period of 2014—2018 the formation of a mass of waste from construction and demolition decreased hyperbolically. Such a mass of construction and demolition waste generation in Vinnytsia region in 2025 is predicted — 331 tons, and in 2030 — 223 tons.

Study case about the production of masonry concrete blocks with CDW and kaolin mining waste

<abstract> <p>The worldwide generation of construction and demolition waste is about 30% to 35% of the total solid waste produced annually. In addition, the extraction of minerals leaves a high-grade environmental liability with tailings, such as kaolin clay, Brazil being one of the countries with the largest deposits and production of this mineral in the world. The kaolin clay extraction serves several industries such as ceramics, crockery, and paper, among others. The objective of this work is to insert these two wastes as raw material of construction elements, specifically masonry concrete blocks, thus giving an end to the residues, demonstrating their reutilization potential. Here, blocks were manufactured with replacement of natural aggregates, stone powder, and sand, by construction and demolition waste and of kaolin clay waste. The replacement percentages were up to 34% and 16%, respectively. The blocks made with pneumatic vibration compacting procedure presented strength beyond than what is established by norm, thus giving a favorable perspective of use for these residues as building elements.</p> </abstract>

Raw materials consumption and demolition waste generation of the urban building sector 2016–2050: A scenario-based material flow analysis of Vienna

Abstract Cities are substantial consumers of raw materials and producers of waste. For this reason, a number of cities including Vienna, defined in their sustainable development strategies a reduction of the raw material consumption as a sustainability target. As the majority of raw materials consumed by cities are used in the building construction sector, buildings play a key role to achieve this target. While many raw material reduction strategies of cities focus on demolition waste recycling, only few studies also consider the reduction of this waste by avoiding the demolition of buildings. Using the case study of Vienna, this article presents the investigation of three urban development scenarios with respect to the demolition of buildings for the time span 2016–2050. The first scenario projects the business-as-usual from the past years (1991–2015), the second foresees a higher demolition of buildings and substitution by new ones, and the third assumes a zero-demolition of selected old buildings, but extensive renovation toward higher thermal insulation standard and attic-extension of these. The results show that in comparison to the year 2015, the business-as-usual reduces the raw material consumption for building construction by −26%, the demolition scenario by −17%, and the renovation scenario by −35%. On a per-capita basis, the reductions are higher. While these results indicate that the renovation scenario is the most suitable to contribute to the sustainable urban development targets in cities like Vienna with respect to the reduction of the consumption of raw material for building construction, further investigations are required to define other measures to finally achieve this target. Furthermore, environmental impacts and land-use of such urban development scenarios should be investigated.

RSM-based evaluation of mechanical and durability properties of recycled aggregate concrete containing GGBFS and silica fume

Concrete is the most consumed material in the construction industry, and using recycled concrete aggregates (RCA), silica fume (SF) and ground-granulated blast-furnace slag (GGBFS) in concrete could reduce its negative environmental impacts by preserving natural resources and reducing construction and demolition (C&D) waste generation and CO2 emissions. Optimizing the mix design based on both mechanical and durability properties of RAC has not been performed. In this study, the mechanical properties and durability of Recycled Aggregate Concrete (RAC) containing GGBFS and Silica Fume (SF) were evaluated via Response Surface Methodology (RSM). The GGBFS was used to reduce the environmental pollution caused by cement production and balancing the negative effect of RA on the mechanical properties of concrete. The results indicated that RA had a negative effect on durability properties of concrete at 7 and 28 ages, while it had no effect on the properties at 90 days. Finally, optimized mix designs were obtained based on two specific scenarios. In the first scenario, the mix design with the highest of both mechanical and durability properties was obtained. In the second one, a mix design with the highest amounts of GGBFS, SF and RA, was achieved, due to the environmental issues related to concrete production.

Influence of Wetting and Drying Cycles on Physical and Mechanical Behavior of Recycled Aggregate Concrete.

Recently, concerns have been rising about the impact of increasing the depletion of natural resources and the relevant generation of construction and demolition waste, on the environment and economy. Therefore, several efforts have been made to promote sustainable efficiency in the construction industry and the use of recycled aggregates derived from concrete debris for new concrete mixtures (leading to so-called recycled aggregate concrete, RAC) is one of the most promising solutions. Unfortunately, there are still gaps in knowledge regarding the durability performances of RAC. In this study, we investigate durability of structural RAC subjected to wet-dry cycles. We analyze the results of an experimental campaign aimed at evaluating the degradation process induced by wetting and drying cycles on the key physical and mechanical properties of normal- and high-strength concrete, produced with coarse recycled concrete aggregates (RCAs) of different sizes and origins. On the basis of the results we propose a degradation law for wetting and drying cycles, which explicitly makes a possible correlation between the initial concrete porosity, directly related to the specific properties of the RCAs and the resulting level of damage obtained in RAC samples.

Characterization study on recycled coarse aggregate for its utilization in concrete - A review

Industrialization and urbanization are two major factors that contribute to the scarcity in construction materials furthermore leading to dependency on alternative materials in construction. Consequently, rehabilitation and retrofitting of structures leads to the generation of Construction and Demolition(C&D) waste which is to be effectively reutilized/disposed. Such C&D wastes can be reutilized as coarse aggregates in concrete termed as recycled aggregate concrete to achieve sustainability in construction. Presence of adhered mortar on the surface of recycled aggregates tends to reduce the quality of recycled aggregate concrete. This paper reviews the statistical data on the generation of C&D wastes around the globe and its percentage of reutilization with a comparison on physical characteristics of C&D wastes with natural coarse aggregate in concrete. Comparative studies on the physical characteristics of recycled aggregates performed by various researchers embark with conclusive remarks to specify its limitation on utilization in structural applications due to the presence of adhered mortar on its surface.

An agent-based model approach for urban demolition waste quantification and a management framework for stakeholders

Along with the rapid growth in construction industry, quantity of construction and demolition (C&D) waste has increased significantly in recent decades. Demolition waste (DW) is identified as one significant stream of C&D waste and it is vital to obtain reliable information of the waste quantity. However, the data of C&D waste generation in China is still insufficient. In this study, an agent-based model is developed to estimate the total volume of DW and the amount of DW generated at each stage of waste disposal in Shenzhen, China. The findings present the greater capacity of deconstruction method in reduction of DW generation than conventional demolition method. In addition, the change from conventional demolition to deconstruction method could bring about a dramatic difference in the amount of construction material saving. However, the results present that change of attitude towards the demolition method is a slow process, which explains the unsatisfactory performance of demolition waste management (DWM) in Shenzhen. Relying on the attitude change of demolition companies is not enough to improve the performance of DWM. Related stakeholders should pay additional attention on DWM. Furthermore, an optimized management framework with involvement of related stakeholders is developed in this study.

An Experimental and Environmental Evaluation of Mortars with Recycled Demolition Waste from a Hospital Implosion in Rio de Janeiro

Construction and demolition waste generation have increased significantly over the century, many times, as a result of obsolete buildings that lead the effort toward demolition. This paper investigates the environmental performance of mortars developed with recycled concrete from the partial building demolition of the Clementino Fraga Filho University Hospital in Rio de Janeiro, Brazil. Life Cycle Assessment is associated with experimental data to validate the application of the residue as an alternative to cement-based mortars. Natural river sand and recycled concrete aggregates, both at a micrometer scale, are employed in the production of four different mortars of compressive strength ranging 50 MPa. The aggregates’ replacement rates defined are 15, 25, and 50% in volume. The recycled microparticles’ mineralogical composition was determined by SEM images and XRD analysis. In addition, the attached cement paste surrounding the original aggregate particle was quantified by chemical attack. Rheological and mechanical properties of the resulting mortars were assessed by the Vane spindle rheometer and uniaxial compressive strength experiments, respectively. The approach to mortars’ environmental performance considered a cradle-to-gate scope using different sensitivity analysis parameters. We demonstrated the feasibility of developing an eco-efficient mortar taking advantage of rarely applied recycled particles. Compressive strength and environmental performance (particularly, the ozone layer depletion potential and abiotic resource depletion potential categories) increased with the aggregate replacement rate. In addition, the rheological results provided relevant data, still insufficient to recycled aggregate mortars, presenting an exponential increase of yield stress with effective water to cement ratio.

Comparative analysis on costs and benefits of producing natural and recycled concrete aggregates: A South African case study

In this paper, comparative analysis of the costs and benefits of producing natural and recycled concrete aggregates for concrete works in South Africa was conducted. The study is based on generation of construction and demolition waste, which continues to escalate as a result of replacement and renovation of existing structures. Presently, most demolition wastes are dumped in landfills or used in low quality applications such as road-based construction etc. One of the mitigation measures employed, is the reuse of demolished concrete as recycled concrete aggregate. The present study shows that the net benefit of producing natural or recycled concrete aggregate, is negative. However, production of recycled concrete aggregates is less expensive than that of natural aggregates. For instance, the long-term cost of producing one tonne of coarse recycled concrete aggregate was about 40 % less than that for coarse natural aggregate. Also, the environmental benefit of producing one tonne of recycled concrete aggregate was approximately 97 % higher than that for natural aggregate. Hence, the commercial production of recycled concrete aggregates from waste concrete should be promoted as a cost-effective and environmentally beneficial approach for implementation in the construction industry.

Development of a Prediction Model for Demolition Waste Generation Using a Random Forest Algorithm Based on Small DataSets.

Recently, artificial intelligence (AI) technologies have been employed to predict construction and demolition (C&D) waste generation. However, most studies have used machine learning models with continuous data input variables, applying algorithms, such as artificial neural networks, adaptive neuro-fuzzy inference systems, support vector machines, linear regression analysis, decision trees, and genetic algorithms. Therefore, machine learning algorithms may not perform as well when applied to categorical data. This article uses machine learning algorithms to predict C&D waste generation from a dataset, as a way to improve the accuracy of waste management in C&D facilities. These datasets include categorical (e.g., region, building structure, building use, wall material, and roofing material), and continuous data (particularly, gloss floor area), and a random forest (RF) algorithm was used. Results indicate that RF is an adequate machine learning algorithm for a small dataset consisting of categorical data, and even with a small dataset, an adequate prediction model can be developed. Despite the small dataset, the predictive performance according to the demolition waste (DW) type was R (Pearson’s correlation coefficient) = 0.691–0.871, R2 (coefficient of determination) = 0.554–0.800, showing stable prediction performance. High prediction performance was observed using three (for mortar), five (for other DW types), or six (for concrete) input variables. This study is significant because the proposed RF model can predict DW generation using a small amount of data. Additionally, it demonstrates the possibility of applying AI to multi-purpose DW management.

AN INVESTIGATION OF THE GENERATION AND MANAGEMENT OF CONSTRUCTION AND DEMOLITION WASTE IN VIETNAM

As a developing country in the context of globalization, Vietnam is experiencing a boom in its economy, characterized by a rapid rate of urbanization nationwide. Together with its benefits, this process also puts pressure on the environment, among which the increasing generation of construction and demolition waste (CDW) is an urgent issue. In this study, the authors conducted an in-depth investigation of various aspects in the generation and management of CDW in Vietnam. Firstly, part of the overall picture of CDW management in Vietnam was revealed in detail from the perspective of demolition contractors, one of the important stakeholders in the field. Their insights provide valuable information on current situation, practice, and attitude towards CDW recycling. Secondly, this paper reports the generation rate of different categories of materials from demolition sites of building structures in Hanoi, Vietnam, with the main focus on crushed concrete and crushed brick (CC–CB) and steel as they make up the majority of the generated waste. In order to achieve two mentioned goals, close contact was constantly kept with a key collaborator – a renowned demolition contractor in Hanoi throughout the investigation. The collaborator provided proper introduction to enable interviews with various other contractors, together with information of buildings being dismantled.

Stress-strain behaviour of steel-fibre-reinforced recycled aggregate concrete under axial tension

The drastic increase in the generation of construction and demolition waste (CDW) is causing serious pollution to the natural environment, such as space reduction, heavy metal contamination, and resource shortage. In this research, steel fibre and recycled coarse aggregate (RCA) are used to form a steel-fibre-reinforced recycled aggregate concrete (SFRAC) to improve the recycling and reuse rate of CDW. Different quality replacement rates of the recycled aggregate (RAR) and volume percentage of the steel fibres (Vf) are used to explore the influence on the tensile behaviour of the concrete. When the Vf increased, the tensile strength and peak strain of SFRAC increased by 10.41–55.90% and 9.70–48.03%, respectively, compared to those of the recycled aggregate concrete (RAC). SFRAC has an energy absorption capacity 5.71–13.31 times higher than that of RAC. The experimental results demonstrate that the internal defects of the RAC on the tensile property can be compensated by the bridging and anchoring effect of the steel fibres. In addition, mathematical formulas are established for predicting the tensile strength, peak strain, and stress-strain curves of the SFRAC. Moreover, SFRAC is recyclable and can be reused at least twice. The method for recycling SFRAC is feasible and cost-effective from an industrial point of view.

Classifying construction and demolition waste by combining spatial and spectral features

The generation of construction and demolition waste (C&DW) has increased on a yearly basis, and the damage caused to the environment is significant. To save resources, C&DW needs to be managed and recycled. Currently, waste-classification methods are mainly based on wind selection, water selection, screening and manual sorting. These methods are inefficient and the classification results are not clean. To achieve efficient and intelligent recycling of C&DW, it is essential to classify the wastes effectively. In this paper, four methods are reported: characteristic reflectivity and extreme learning machine (ELM); first-order derivative of characteristic reflectivity and ELM; grey level co-occurrence matrix and ELM and convolutional neural network. These methods were used to classify typical types of hard-to-distinguish waste: wood, rubber, brick and concrete. It was found that each method had inadequacies, and the correct rate was between 82·22 and 89·33%. Therefore, a weighted fusion of membership matrix, which combine all four methods, was proposed. As a result, the correct rate in repeated experiments significantly improved to 95%. The classification results can be used in further study about automatic sorting of C&DW using robotics instead of people.

Generation and Prediction of Construction and Demolition Waste Using Exponential Smoothing Method: A Case Study of Shandong Province, China

The output of construction and demolition (C&D) waste in China has been rapidly increasing in the past decades. The direct landfill of such construction and demolition waste without any treatment accounts for about 98%. Therefore, recycling and utilizing this waste is necessary. The prediction of the output of such waste is the basis for waste disposal and resource utilization. This study takes Shandong Province as a case, the current output of C&D waste is analyzed by building area estimation method, and the output of C&D waste in the next few years is also predicted by Mann–Kendall trend test and quadratic exponential smoothing prediction method. Results indicate that the annual productions of C&D waste in Shandong Province demonstrates a significant growth trend with average annual growth of 11.38%. The growth rates of each city differ a lot. The better the city’s economic development, the higher the level of urbanization, the more C&D waste generated. The prediction results suggest that the output of C&D waste in Shandong Province will grow at an average rate of 3.07% in the next few years. By 2025, the amount of C&D waste will reach 141 million tons. These findings can provide basic data support and reference for the management and utilization of C&D waste.

Flow of waste and a method for prediction of demolition waste generation from buildings – A case study in Hanoi, Vietnam

Being the capital of Vietnam, a dynamic developing country, Hanoi is experiencing a rapid rate of urbanization and economic growth which leads to the continuing increase of construction and demolition activities. In the recent few decades, construction and demolition waste has been accounted for a large amount of solid waste in urban areas, among which demolition waste (DW) is the major content. This study aims to sketch the flow of DW post-demolition, as well as to provide an approach to predict the estimated DW generation in the future in Hanoi. Data of DW generation rate from previous study in Hanoi is combined with statistics of construction in the city to work out a reasonable model of projection of DW for further recommendations for managing this type of waste for sustainable development.

A review on the reactivation of hardened cement paste and treatment of recycled aggregates

The generation of construction and demolition waste (CDW) worldwide keeps on escalating due to growth in infrastructure and the related refurbishment or replacement of existing structures. Numerous research studies on the utilisation of CDW materials in the production of new concrete have been conducted, from which it has been established that their use generally leads to inferior mechanical properties of the resulting concrete. As such, the general acceptance and conventional utilisation of CDW in the construction industry is undermined. The concept of a triple-layered interfacial transition zone is suggested to be the main reason for the inferior mechanical properties exhibited by recycled aggregate (RA) concrete. Past research on the reactivation of hydrated cement paste and on improving the quality of RAs by the use of different treatments, was reviewed. The review revealed that a combination of mechanical grinding and thermal treatment at temperatures of 500–800°C is an effective means of activating the cementitious properties of hardened cement paste. Adhered mortar removal and mortar fortification are the main approaches for enhancing the properties of RAs. Mechanical abrasion and/or thermal treatment at a temperature of 500°C, are the most effective techniques for improving the properties of RAs.

Unification of the development of information models of buildings at the demolition stage

The study aims to develop standardized BIM methods for buildings that are part of the Moscow city renovation program. This problem is extremely urgent, since there are no digitized sources of typical projects of the last century, and this complicates the process of calculating the generation of construction and demolition waste and casts doubt on its accuracy. At the stage of high quality and timely dismantling phase (calculation of the weight of construction and demolition waste, scheduling of work and transportation of waste), this process can be automated using information modeling software – Autodesk Revit 2019. This will complement the existing information model by including in it one of the final stages of the building’s life cycle – dismantling, which in transparency, accessibility and completeness will not be inferior to the blocks of design, examination, construction and operation. On the basis of albums of typical building projects, you can get a lot of information to create the necessary project families and specifications, which will greatly simplify and speed up the process of developing building demolition projects in the future, since with each new project libraries of elements, materials, families will be supplemented. The article presents the process of developing a project template for the phase of the dismantling of buildings. A new project parameter has been created, assigned to each material of the project template, the necessary parametric and design characteristics have been assigned for further calculations based on the simulated building design, a design specification has been developed, on the basis of which data on the weight of construction and demolition waste can be quickly obtained, relevant checks carried out for different types of developed and basic project families.

Evaluating recycling potential of demolition waste considering building structure types: A study in South Korea

This study investigates the recycling potential of demolition waste (DW) according to building structure, while considering environmental and economic aspects For that, this study surveyed 1,034 residential buildings in Korea immediately before demolition to collect reliable information on demolition waste generation rates (DWGRs). This study classified the removal stages of buildings into the demolition, collection and sorting, transportation, and disposal stages. This study suggested a method for carbon emissions calculation for each stage and carried out an inventory analysis. The economic value of recycled DW materials was also calculated. Furthermore, the recycling potential was calculated based on the economic value and the environmental load for the current scenario, i.e., the current waste recycling rate in Korea, and the maximum scenario, i.e., the maximum theoretical recycling rate. Regarding building structures, the recycling potential of wooden structures was the highest in both the scenarios. However, masonry-block structures showed improved recycling potential in the maximum scenario. Regarding DW types, the recycling potential of plastics was the highest, with plastics from reinforced concrete (RC) structures showing 6.6 times higher recycling potential than those from wooden structures. And the possibility of improving the recycling potential was higher for glass and plastics than aggregates, timber, and metals. Through the above research, this paper devised an approach that can be used to plan a detailed construction and demolition waste management strategy, considering building structures and DW types, and this method can also be applied to other regions and countries.

Dynamic material flow and stock analysis of residential buildings by integrating rural–urban land transition: A case of Shanghai

In rapidly developing countries, such as China, considerable quantities of construction materials have been mobilized with the fast expansion of urban areas. The rural to urban land use transition, especially the upgrade and redevelopment of original rural areas, is a noted driver of material flows. This rural–urban land transition should be incorporated into material flow and stock analyses to provide a more accurate analysis. In this study, a dynamic material flow and stock model that integrates the historical rural–urban land transition was developed to explore the quantity of material stocks and demolition waste from residential buildings in Shanghai—the largest megacity in China from 1950 to 2100. Our results show that the material stocks from residential buildings in Shanghai increased 41-fold from 1950 to 2010, about 957 MMT (million metric tons), and is estimated to be saturated around 2040. Material stocks have experienced asynchronized growth in rural areas, central urban areas, and rural–urban land transition zones (RULT zones) in Shanghai. Until 2040, the RULT zones in Shanghai will be the largest material repository (62%), followed by central urban areas (20%), and rural areas (18%). The amount of demolition waste, which accounted for 10 MMT in 2010, is expected to peak at 29 MMT in 2060s. This suggests the need for a deliberate investment plan to increase waste treatment capacity. In addition, the dominant component of demolition waste will shift from brick to concrete after 2020s. The RULT zones will contribute two-thirds of demolition waste to Shanghai until the 2060s. If we do not consider the reality of the physical status of buildings in RULT zones, the demolition waste will be underestimated by the maximum of 57% in 2003 in urban areas. The key findings on the trend of construction and demolition (C&D) waste generation and the significant contribution of RULT zones can be used as a reference for the strategic planning of treatment facilities. This research framework can be also used to estimate the amount of C&D waste in other fast-developing cities in China and other countries.

Utilization of Construction and Demolition Waste Along with Fly Ash waste in Preparing Non-Autoclaved Aerated Concrete

China’s construction industries are rapidly increasing, and with that generation of Construction and Demolition waste is also growing, and another side industrial waste such as fly ash produced by a thermal power plant, Associated environmental issues, it is essential to utilize in any form; Studies by concrete experts have indicated the feasibility of suitably handling and recycling such waste in new concrete, mainly for basic-level applications. Non-autoclaved aerated concrete is a lightweight substance that could be used as substitute building materials; it is generally made up of raw materials such as Cement, quicklime, gypsum, sand, and expansion agent like an aluminum powder; in this study, 40% waste utilized, Construction and demolition waste (5%,10%,15%,20% ………40%) and Fly ash (35%,30%,25%,20%......0%) accordingly, while expansion agent maintained constant at 0.06%. The compressive strength of the final material checked after (7,14,21 and 28 days) respectively, obtained maximum strength after 28 days; this study goals to design a low cost, Non-autoclaved aerated concrete material and to reuse the waste produced from different sectors, mainly from the construction sector Keywords: Non-Autoclaved concrete, Lightweight concrete, Eco-friendly, Construction and Demolition waste, Fly ash