Yes / Construction and demolition waste (CDW) management and recycling practices are crucial for transitioning to a circular economy. This study focuses on the detailed characterization of CDWs, including hollow brick (HB), red clay brick (RCB), roof tile (RT), concrete (C), and glass (G), collected from seven different sites. The CDWs were characterized based on particle size distribution, chemical composition, and crystalline nature. Pozzolanic activity was evaluated through compressive strength measurements of cement mortars with 20% cement replacement by CDWs at 7, 28, and 90 days. The results showed that clayey CDWs exhibited similar physical/chemical properties and crystalline structures. Compositions of Cs varied significantly based on their original materials. CDWs satisfied the minimum strength activity index for supplementary cementitious materials, with pozzolanic activity influenced by fineness and SiO2+Al2O3 contents. The average strength activity indexes for HB, RCB, RT, C, and G were 84.5%, 86.3%, 83.4%, 80.7%, and 75.8%, respectively. Clayey CDWs contributed to mechanical strength development, while Cs' contribution was related to hydration of unreacted cementitious particles. G exhibited the weakest pozzolanic activity due to its coarser particle size. Overall, CDWs demonstrated suitable properties for use as supplementary cementitious materials in PC-based systems.

This essay will address if and how it is possible to reuse and recycle wood waste and CDWW (construction and demolition wood waste). The background will have a short introduction and then be divided into 3 sections. The first section addresses similarities and differences between linear vs. circular economy. The second section will take up bioeconomy and how it is managed in the different countries in the world, and the last part takes up wood waste management. The purpose of this thesis is to investigate from literature if it is possible to reuse and recycle wood waste and CDWW. By reviewing case studies, see if it is possible to implement a practical sustainable recycling worldwide. There are four questions that will be answered to see if it is possible. Those are: 1, Are there enough volumes of wood waste for it to be worth to reusing/recycling it? 2, What opportunities does it provide and how can it affect society, economy, and the environment? 3, Is it worth investing in facilities that only accept wood waste and reuse/recycle the material? 4, How have the trends with wood waste been according to the data collected? The methods that have been used are literature study, qualitative and quantitative methods. Qualitative as an interview has been conducted, and quantitative as data for wood waste in Borås has been compiled. The result showed that there exist enough volumes for it to be worth reusing and recycling, however, the volumes has gone down significantly and are not stable, though this could be argued due to the COVID-19 pandemic and will most likely change and go up in volume within the next few years. There have not been any studies on how the society could be affected by reusing and recycle wood waste, although from an economic and environmental perspective it shows a positive outcome, such as new jobs get created and less deforestation and less reduction of biological diversity. Depending on the type of wood waste the facility receives, it can affect whether it is profitable or not, as the more hazardous chemicals exist in the wood residues, the more difficult and expensive the treatments and recycling becomes.

No description available.

Byggsektorn genererar årligen stora ekologiska fotavtryck genom rivning av byggnader, då behovet av allt fler byggnader ökar i städerna, men det dessvärre råder en brist på exploaterbar mark. En alternativ lösning för att staden fortfarande ska kunna växa är att bygga på höjden och på så sätt förtäta städerna. Detta görs idag ofta genom rivning av den befintliga byggnaden för att kunna ersätta den med nybyggnation, vilket inte alls är hållbart. Det är inte rimligt att riva fullt fungerande byggnader av bra kvalité enbart för att öka mängden LOA1 och BOA2. Återanvändning är nyckeln för ett mer hållbart byggande och en alternativ lösning för att öka LOA och BOA är då att genom påbyggnation addera ytterligare våningar på redan befintliga byggnader. Syftet med denna utredning är att underlätta beslutstagandet i utredandet av det befintliga beståndet. Genom att analysera byggnaders potential för påbyggnation i tidigt skede så kan riskerna minimeras för oväntade kostnader.Vi har genom en kvalitativ utredning som främst tagits fram genom intervjuer med branschkunniga, arbetat för att identifiera mönster hos fyra redan slutförda påbyggnationer som gjorts av Fabege. Vi anser att genom att identifiera de fallgropar som kan uppkomma vid arbeten med påbyggnationer som ekonomiskt och tidsmässigt kan minimera risk och förhindra problem. Detta utförs i förhoppning att uppmuntra fler byggaktörer att påbörja fler påbyggnationer, eftersom påbyggnader i dagsläget associeras med krångel och oväntade kostnader, vilket gör att många aktörer inte vågar försöka. Denna metod som tas fram blir i form av en lathund som stegvis kan följas, där samtliga centrala faktorer vilka vi i denna utredning kallar benchmarks3 gås igenom. Varje central faktor som bedömdes som avgörande för en lyckad påbyggnad klassades i skala A, B och C för hur pass viktig den faktorn ansågs för att klara av en storskalig påbyggnad. Med storskaliga påbyggnationer menar vi främst större kontorsbyggnader där cirka 4–5 våningar är aktuellt att byggas på.För att enkelt kunna göra bedömningen så inkluderar lathunden ett polärdiagram där de olika faktorerna sammanställts. Genom ifyllning av denna, utifrån den befintliga byggnadens förutsättningar kan utredaren då få en visuell överblick över vilka faktorer som kan komma att vara hinder under byggarbetets gång.Lathunden inkluderar även en stegvis beskrivning på hur processen inleds för en påbyggnation och även fördjupningspunkter som ska ses över i tidigt skede för att minimera framtida kostnader och svårigheter.Nyckeln till en lyckad påbyggnation är goda kunskaper och grundligt förarbete. Därför tar vi fram denna lathund för att upplysa vad som är viktigt att se över i tidigt skede och lägger en god grund kunskapsmässigt och översiktmässigt. Detta för att fler byggnader ska kunna prövas som potentiella påbyggnationer. / The construction sector generates large ecological footprints annually through the demolition of buildings, as the need for more and more buildings increases in the cities, but unfortunately there is a shortage of exploitable land. An alternative solution for the city still being able to grow is to build on the height and thus densify the cities. This is often done today by demolition of the existing building in order to be able to replace it with new construction, which is not at all sustainable. It is not reasonable to demolish fully functional buildings of good quality only to increase the amount of LOA and BOA. Recycling is the key to a more sustainable construction and an alternative solution for increasing LOA and BOA is to add additional floors to already existing buildings by extension. The purpose of this investigation is to facilitate the decision making in the investigation of the existing stock. By analyzing the potential of buildings for upgrading at an early stage, the risks can be minimized for unexpected costs.Through a qualitative study, which was mainly produced through interviews with industry experts, we have worked to identify patterns of four already completed extensions made by Fabege. We believe that by identifying the pitfalls that can arise during construction with extension work can economically and temporally minimize risk and prevent problems. This is done in the hope of encouraging more companies in the field to start more constructions of this kind, as this type of building is currently associated with hassle and unexpected costs, which means that many players do not dare to try. This method that is developed will be in the form of a “reference card” that can be followed step by step, where all the key factors that we in this investigation call “benchmarks” are reviewed. Each central factor that was judged to be crucial for a successful extension was classified in scale A, B and C for how important this factor was considered to cope with a large-scale extension. By large-scale superstructures we mean mainly larger office buildings where approximately 4-5 floors are currently being built.To be able to easily make the assessment, the crib includes a polar diagram in which the various factors are compiled. By filling this in on the basis of the existing building's conditions, the investigator can then get a visual overview of what factors may be obstacles during the construction work.The guide also includes a step-by-step description of how the process begins for an extension and also in-depth points to be reviewed at an early stage to minimize future costs and difficulties.The key to a successful extension is good knowledge and thorough preparation. Therefore, we present this reference card to inform what is important to revise at an early stage and put a good foundation of knowledge and overview. This means that more buildings can be tested as potential additions.

Yes / CDW-based concrete requires alkali-activators to generate geopolymerization process. These alkali-activators are difficult to be handled at the construction site and one of the rational ways to built reinforced geopolymer structures is the prefabricated construction. The connection of the precast structures is the most vulnerable component under the effect of seismic actions. Proper detailing and design of connections are crucial for sufficiently-ductile performance under seismic loading. Additionally, to achieve the disassembling and reusing of structural members, a demountable connection, i.e., dry connection, should be used instead of a wet connection. In this study, four novel fully-demountable connections for reinforced construction and demolition waste-based (CDW) geopolymer concrete members are developed. Seismic performances of these different demountable connections and one reference monolithic connections are experimentally investigated. The connections are subjected to reversed cyclic lateral displacements under constant axial loading. Comparisons are made referring to observed damage patterns, connection strengths, moment–curvature relations, initial stiffnesses, plastic hinge lengths, and energy dissipation characteristics of the proposed demountable connections and the monolithic connection. The results of the experimental study indicate that one proposed demountable connection exhibited larger lateral capacity and better seismic performance than its monolithic counterpart, whereas the other three proposals showed less performance than the monolithic counterpart. / The authors gratefully acknowledge the financial assistance of the European Union’s Horizon 2020 research and innovation programme under grant agreement No: 869336, ICEBERG

Yes / Developing a fast, cost-effective, eco-friendly solution to recycle large amounts of construction and demolition waste (CDW) generated from construction industry-related activities and natural disasters is crucial. The present investigation aims to offer a solution for repurposing CDW into building materials suitable for accelerated construction and housing in developing countries and disaster-prone areas. Feasibility of recycled concrete aggregate (RCA) inclusion in geopolymer mortars constituted entirely from CDW (masonry elements) was investigated via an environmental impact-oriented approach by addressing the composition related key parameters. Mechanical performance was evaluated through compressive strength tests, and scanning electron microscope (SEM) imaging with line mapping analyses were carried out to monitor the interfacial transition zone (ITZ) properties. To investigate the environmental impacts of the geopolymer mortars and highlight the advantages over Portland cement-based mortars, a cradle-to-gate life cycle assessment (LCA) was performed. Findings revealed that roof tile (RT)-based geopolymer mortars mainly exhibited better strength performance due to their finer particle size. Mixtures activated with 15 M NaOH solution and cured at 105 °C achieved an average compressive strength above 55 MPa. RCA size was the most influential parameter on compressive strength, and a smaller maximum RCA size significantly increased the compressive strength. Microstructural analyses showed that the ITZ around smaller RCAs was relatively thinner, resulting in better compressive strength results. LCA proved that CDW-based geopolymer mortars provide the same compressive strength with around 60% less CO2 emissions and similar energy consumption compared to Portland cement-based mortars. / This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 894100. The authors also wish to acknowledge the support of the Scientific and Technical Research Council of Turkey (TUBITAK) provided under project: 117M447

Sustainable demolition waste management is rarely practiced within the construction industry. This is mainly due to the fact that the decision-making process for sustainable demolition waste management is a very resource-demanding and time-consuming task in terms of data collection and data management. The decision-making process includes multiple analyses of possible demolition waste management alternatives from economic, environmental, and social perspectives. Such analyses require waste managers to capture and manage huge amounts of data scattered within fragmented data sources at the end-of-life of a building. The process of capturing and managing this information for the building end-of-life would be time-consuming and costly. Therefore, the waste managers are reluctant to pursue sustainable demolition waste management practices in order to prevent potential delays and incurred costs. This research identified information that is required to conduct sustainable demolition waste management analyses. The identified information was then classified based on information sources. An object-oriented data model (OODM) was proposed to allow the waste managers to more efficiently store and manage the information at the end-of-life phase. Furthermore, a sustainable demolition waste management prototype application was developed to demonstrate how the required information is captured from different sources of data, stored within OODM classes, and retrieved from the integrated database. Finally, the proposed OODM was verified in terms of its scope, flexibility, and implementability. The goal of the research is to offer a method for storing and managing end-of-life information in an efficient and effective manner to support sustainable demolition waste management decision making. To achieve the goal, this dissertation outlines the objectives of the research, the methodologies used in developing the object-oriented data model, conclusions, limitations, and potential future research work. / Ph. D.

Yes / Geopolymer concrete is a promising candidate to replace conventional concrete as geopolymer concrete depends on alkali-activated binders instead of Portland cement. The elimination of cement from the mixture results in the reduction of the greenhouse gas release. From the literature, it is known that the micro-scale characteristics of the geopolymer concrete are similar to its counterparts. However, the structural performance of geopolymer elements should be investigated in detail. Therefore, in this study, the structural performance of reinforced geopolymer concrete beams is compared by conducting bending tests to determine the shear behavior of new generation geopolymer concrete produced from entirely construction and demolition wastes (CDW). In these tests, geopolymer concrete with recycled aggregates, geopolymer concrete with natural aggregates, conventional concrete with recycled aggregates, and conventional concrete with natural aggregates are used in order to study the possibility of reaching fully-recycled construction materials. Three different shear-span-to-depth ratios (a/d) are utilized to investigate the different modes of failure. Therefore, the structural performance of beams was, firstly, compared for mixtures without recycled aggregates to control the possible side effects of 100% recycled concrete construction. Load-deflection curves, moment-curvature curves, and crack patterns were utilized to conclude the performance of geopolymer concrete. Test results revealed that geopolymer concrete beams exhibited similar performance to the conventional concrete beams of the same grade. However, the inclusion of recycled aggregates caused a shift in the failure mechanism from shear-dominated to flexure-dominated, especially in specimens with larger a/d ratios. Finally, the capacity prediction performance of current codes, i.e., TS500 and ACI318, are also examined, and the calculations resulted that the current code equations have a percentage error of approximately 55% on average, although TS500 equations performed slightly better. / The authors gratefully acknowledge the financial assistance of the Scientific and Technical Research Council (TUBITAK) of Turkey and the British Council provided under projects: 218M102 and European Union’s Horizon 2020 research and innovation programme under grant agreement No: 869336, ICEBERG (Innovative Circular Economy Based solutions demonstrating the Efficient recovery of valuable material Resources from the Generation of representative End-of-Life building material).

Yes / Construction and demolition waste (CDW) has been recently identified as a potential aluminosilicate source for geopolymers. However, the available research has mainly focused on developing CDW-based geopolymer pastes and mortars, while studies on geopolymer concretes sourced from CDW have been very limited. Thus, the current study aimed at experimentally identifying different CDW materials suitable for producing geopolymer concretes. Additionally, the study analysed the mechanical, microstructural, and environmental properties of CDW- based geopolymer concrete produced. In this regard, the effect of relevant parameters on the compressive strength development of CDW-based geopolymer concretes was comprehensively investigated, including those related to precursor types/fineness, alkali activator solution, aggregate type/size and curing regimes. Microstructural analyses were also conducted on the selected samples (100% brick waste, 100% tile waste, 100% concrete waste and 75% brick waste + 25% GGBS). Finally, the environmental impact of geopolymer concrete was assessed and compared with similar traditional concrete. Results showed that employing CDWs alone is not suitable to achieve sufficient strengths under all curing regimes. However, the inclusion of 25% GGBS significantly improved the strength performance of CDW-based geopolymer concrete, in comparison to other supplementary cementitious materials (SCMs) such as Class-C fly ash and calcium hydroxide. The particle size of CDWs and concentration of alkaline activators highly affect the performance of CDW-based geopolymer concretes. Utilization of CDWs with particles finer than 75 μm and high concentrations of NaOH (12 M) is recommended to achieve good performance. The results also indicate that almost similar energy is needed for producing CDW-based geopolymer and OPC-based traditional concrete, whereas a huge reduction in CO2 emission (∼40%) was estimated in the case of geopolymers. The outcomes of the current study are expected to contribute to the advancement of geopolymer concrete derived from CDW in addition to providing valuable insights into this type of concrete for practitioners and academics.

Yes / Geopolymers have been recognised as a viable replacement to ordinary Portland cement (OPC), providing a cleaner solution since it can significantly reduce greenhouse gas emissions as well as accomplishing effective waste recycling. Construction and demolition waste (CDW) has been recently identified as raw materials for geopolymers due to its availability and high contents of silica and alumina. This paper aimed at reviewing the current state-of-the-art on the geopolymer paste, mortar, and concrete production and their properties, with special attention paid to geopolymers incorporating CDWs. The review covers brief assessment of using CDWs in concrete, the mix design of geopolymer mixtures in addition to identification of the main factors influencing the performance of geopolymer containing CDW. The most recent data related to the mechanical and durability properties of CDW-based geopolymers are presented, while the cost and environmental impacts of using recycled materials in producing geopolymer concretes are also discussed. Geopolymer concretes have a vast range of possible applications, however, there are still several barriers facing commercialisation of geopolymers in construction industry. The review indicated that it is possible to produce geopolymer concretes from CDW-based materials with properties comparable to OPC-based ones; however, the selection of proper material composition should be carefully considered, especially under normal curing conditions.