Alternative Reuse Research Articles

A Collaborative Multi-Criteria Decision-Making Framework for the Adaptive Reuse Design of Disused Railways

With an increasing focus on sustainable development and the reuse of disused infrastructure, there is a pressing need for effective decision-making methods. This study explored the use of the PROMETHEE method within a collaborative decision-making framework to assess the adaptive reuse options for a disused railway in Sicily, Italy. Using a participatory paradigm, the research actively involves stakeholders in the assessment process. The collaborative PROMETHEE approach acts as a tool for multi-criteria decision analysis, facilitating the comparison and prioritization of different reuse alternatives based on predefined criteria. The research highlights the effectiveness of PROMETHEE in streamlining decision-making processes for adaptive reuse efforts, particularly in the context of integrated conversions of abandoned railways. By combining multi-criteria decision analysis with collaborative methods, the study contributed to the formulation of sustainable and socially responsible strategies for the valorization of disused railway infrastructure. The results underline the importance of collaborative decision-making processes and the instrumental role of PROMETHEE in assisting stakeholders in evaluating and selecting adaptive reuse options for disused railways, thereby, in turn, promoting the sustainable development of these sites.

Exploring the social metabolism of urban wastewater reuse: Analysis framework and a case study in South-Central Chile

Although wastewater reuse is a vital strategy for mitigating water scarcity, its implementation is complex and faces several challenges. To effectively inform decision-makers, comprehensive evaluations are essential, considering the strategy's benefits and socio-ecological constraints in a case-specific manner. This study employs the social metabolism concept to assess the sustainability of wastewater reuse, through the joint application of the Material Flow Analysis (MFA) and Multiscale Integrated Assessment of Societal and Ecological Metabolism (MuSIASEM) tools. We analyze key aspects of wastewater reuse, including its potential as a water source, its technical challenges, and main social constraints.The results of our analysis highlight the potential of wastewater reuse to improve urban self-sufficiency, replace water in relevant economic activities at the regional level, and avoid the environmental impacts of wastewater discharge. Nevertheless, the viability of wastewater reuse is constrained by variations in wastewater flow and effluent quality. This limitation is further compounded by social barriers, which become more pronounced with increased contact with reclaimed water. Overall, the proposed framework serves as a valuable tool for evaluating wastewater reuse alternatives. It can be enriched by in-depth assessments of critical problems, providing a comprehensive approach to address the multifaceted aspects of sustainable wastewater reuse.

Use - clean - repeat: Understanding user, product, and context to design for long-term reuse

With escalating concerns about pollution and resource depletion caused by single-use products, the need to adopt reusable alternatives is widely acknowledged. This paper presents an investigation into the barriers and motivators to the long-term use of reusable products. The qualitative research consists of thirty-two semi-structured interviews with consumers, addressing the acquisition, usage, and discontinuation of the use of reusable products. From the results, we distinguished four product categories - intimate care, daily shopping, at home, and on the go - providing tailored insights into specific barriers. Next to this, we argue that willingness, ability, and routine are needed to increase the chances of successful long-term reuse. Based on these insights, we developed suggestions for designers including several design strategies and intervention points. We recommend incorporating the suggested product categories into future research, delving into persistent usage thresholds through case studies. Besides this, alternative reuse models should be further explored.

Life cycle assessment of wastewater reuse alternatives in urban water system

Increasing water stress necessitates adopting wastewater reuse for sustainable living in urban environment. Trade-offs exist between different wastewater reuse applications and their environmental impacts. The impacts associated with developing urban water systems (UWSs) are not known, and city scale wastewater reuse in general is not well understood. This study investigates indirect, direct, non-potable and hybrid wastewater reuse scenarios in a real UWS to suggest environmentally sustainable reuse strategy using life cycle approach. The study develops a comprehensive life cycle inventory of actual water and wastewater utilities. Results show that all environmental impacts except eutrophication increases for direct potable and hybrid reuse. The centralized non-potable reuse (NPR) had lowest impact scores related with ecotoxicities while impacts including global warming were equivalent to the baseline. The study recommends adopting centralized NPR in developing UWSs while highlighting the treatment processes and impacts for reuse scenarios favorable in high to extreme water stressed regions.

Adaptive Reuse of Urban Heritage in Contested Urban Contexts

The world is facing global challenges that are dramatically changing the social and physical environments, resulting in cultural confrontation. Rapid urban growth, and gentrification increase urban pressure while jeopardizing social cohesion, multicultural values and local economies. Moreover, environmental factors associated with climate change challenge the way cities respond and adapt, as their assets have to be re-designed to meet the current and future generation needs. One response to these challenges is adaptive reuse, the transformation of the function of an underused structure into a new use. This process turns the cities’ elements in decline into development catalysers. The adaptation to these changes is often a source of conflict, as urban policies lack citizen engagement in the redefinition of public space, resulting in more disagreement. This is particularly acute when addressing contested communities, as their continuous evolution directly influence the adaptation of cultural heritage. Considering these aspects, this research question is responded: ‘How can socio-spatial conflicts that result from contested identities be mitigated through the adaptive reuse of urban heritage?’. The relations between Adaptive Reuse, Urban Heritage and Contested Identities are studied, resulting in the research’s objective: to develop an integrative methodology to evaluate urban heritage adaptive reuse alternatives in contested urban contexts, using the case of Acre (Israel). This final outcome is proposed as a tool for decision-makers and urban planners that provides information-based results to be applied in urban design practice, aiming to translate the theory into practice, and to bridge the gap between global goals and local issues.

A multi-criteria decision framework for circular wastewater systems in emerging megacities of the Global South

Lima faces increasing water stress due to demographic growth, climate change and outdated water management infrastructure. Moreover, its highly centralized wastewater management system is currently unable to recover water or other resources. Hence, the primary aim of this study is to identify suitable wastewater treatment alternatives for both eutrophication mitigation and indirect potable reuse (IPR). For eutrophication mitigation, we examined MLE, Bardenpho, Step-feed, HF-MBR, and FS-MBR. For IPR, we considered secondary treatment+UF + RO + AOP or MBR + RO + AOP. These alternatives form part of a WWTP network at a district level, aiding Lima's pursuit of a circular economy approach. This perspective allows reducing environmental impacts through resource recovery, making the system more resilient to disasters and future water shortages. The methods used to assess these scenarios were Life Cycle Assessment for the environmental dimension; Life Cycle Costing for the economic perspective; and Multi-Criteria Decision Analysis to integrate both the quantitative tools aforementioned and qualitative criteria for social and techno-operational dimensions, which combined, strengthen the decision-making process. The decision-making steered towards Bardenpho for eutrophication abatement when environmental and economic criteria were prioritized or when the four criteria were equally weighted, while HF-MBR was the preferred option when techno-operational and social aspects were emphasized. In this scenario, global warming (GW) impacts ranged from 0.23 to 0.27 kg CO2eq, eutrophication mitigation varied from 6.44 to 7.29 g PO4− equivalent, and costs ranged between 0.12 and 0.17 €/m3. Conversely, HF-MBR + RO + AOP showed the best performance when IPR was sought from the outset. In the IPR scenario, GW impacts were significantly higher, at 0.46–0.51 kg CO2eq, eutrophication abatement was above 98 % and costs increased to ca. 0.44 €/m3.

Reusing Ceramic Waste as a Precursor in Alkali-Activated Cements: A Review

Concrete and ceramic products are among the most widely used materials in the construction sector. The production of ceramic materials has significantly grown in recent years. Concrete is one of the most widely used materials worldwide and most of its carbon dioxide (CO2) emissions are attributed to Portland cement (PC) production. This review analyzed previous research works into the use of ceramic waste (CW) as a precursor in alkali-activated (AA) cements. The physico-chemical properties of different CW materials were analyzed, and the properties and environmental impact of three main categories of AA CW cements were explored: those developed solely with CW; hybrid cements combining CW with traditional binders (PC, calcium hydroxide or calcium aluminate cement); combinations of CW with other precursors (i.e., blast furnace slag, fly ash, fluid catalytic cracking residue, etc.). The results evidenced that CW can be successfully employed as a precursor in AA cements, particularly in the context of prefabricated products where thermal curing is a prevalent procedure. When enhanced mechanical strength is requisite, it is feasible to attain improvements by employing hybrid systems or by combining CW with other precursors, such as blast furnace slag. This new alternative reuse option allows progress to be made toward sustainable development by reducing not only CO2 emissions and embodied energy compared to PC but also PC consumption and CW accumulation in landfills.

Wastewater Treatment in Central Asia: Treatment Alternatives for Safe Water Reuse

Due to water scarcity and ready availability, treated wastewater in Central Asia is increasingly reused and seen as a valuable resource, requiring effective management with particular care for human health, environmental protection, and water security. Due to limited technical and economic support and poorly developed regulatory systems, many cities have inadequate wastewater treatment infrastructure. Improved wastewater effluent management is paramount due to its relationship with surface and groundwater quality used for drinking and agricultural irrigation. This paper presents a brief review of the published literature reporting on current wastewater treatment technologies and effluent composition, with particular attention paid to reuse needs. The impact of these practices on water quality is further assessed from information and reports gathered from various sources on the quantity and quality of surface waters and groundwaters. Finally, alternatives to current wastewater treatment practices in Central Asia will be explored with a particular emphasis on the removal of contaminants of emerging concern, including biological treatment systems, adsorption, advanced oxidation processes, and managed/unmanaged aquifer recharge techniques based on permeable reactive barriers, aiming to increase the availability and quality of surface waters and groundwaters for safe water reuse.

Euphorbia tirucalli: potential plastic digester and in bioeconomics

In view of the global concern with persistent plastic waste in the environment, the present study seeks reuse and reuse alternatives to reduce pollution through extracts of the Euphorbia tirucalli specimens. The method involved collecting latex from different geographic regions and evaluating the corrosive and shrinkage effects of aqueous plant extracts on polypropylene. Results indicate variations in the ability of extracts to interact with plastic, with some showing corrosive and digesting effects over time. This approach, exploring the enzymatic and corrosive action of Euphorbia tirucalli extracts, suggests potential for the degradation of non-degradable plastics over time. The study also underscores the importance of bioengineering as an innovative approach to solving environmental problems. The research highlights the relevance of the search for sustainable solutions for the management of plastic waste, aiming at promoting environmental sustainability and mitigating environmental impacts. Although more in-depth research is needed to understand the mechanisms of action of Euphorbia tirucalli extracts and their viability on a large scale, this approach offers promising bioeconomics perspectives for the degradation of persistent plastics in nature and the appreciation of ethnic communities that already practice these precepts. In summary, the study highlights the importance of exploring natural alternatives to deal with plastic pollution and contribute to the conservation of the environment.

Analysis of drying kinetic of brewer´s spent grains: effect of the temperature on the physical properties and the content of bioactive compounds

Background: Brewer´s spent grain (BSG) is a biomass by-product generated in large volumes during industrial beer production. BSG has become a growing environmental problem, as most breweries discard it inappropriately, negatively impacting the environment. Alternatives for the exploitation of this by-product have consisted of elaborating food supplements for farm animals, obtaining biofuels, developing adsorbents, and obtaining substances for the food industry. However, the high moisture content in BSG (approximately 70%), poses a significant challenge in exploring various reuse alternatives. Therefore, the implementation of a pre-drying process becomes essential. Objective: This study aimed to analyze the BSG drying kinetics at different temperatures and the effect of the drying temperature on the physical properties and the content of bioactive compounds. Methods: BSG samples were dried at different temperatures (50, 60, 70, 80, 90, and 105°C) and analyzed for their moisture ratio, water activity, total polyphenol content (TPC), and DPPH (1,1-diphenyl-2-picrylhydrazil) radical scavenging activity. Also, four kinetics models were fitted to the drying data. Results: It was determined that the effective diffusivity was between 5.23x10-10 (m2/s) and 2.49x10-09 (m2/s), and the value of the activation energy was 28.05 kJ/mol. In addition, it was found that the content of phenolic compounds (1.27±0.120 mg gallic acid equivalents /g) and the DPPH radical scavenging activity (0.21±0.015 mg gallic acid equivalents /g) were not significantly affected by the variation in the drying temperatures studied. Conclusions: From an operational point of view, the most suitable temperature for the drying process of BSG was 105°C since it would allow to reach shorter drying times, and the TPC was not affected markedly by the range of temperature studied.

Photolysis of chloramines in vacuum-UV and vacuum-UV/chlorine advanced oxidation processes for removal of 1,4-dioxane: Effect of water matrix, kinetic modeling, and implications for potable reuse

Advanced oxidation processes (AOPs) are a key step in eliminating persistent micropollutants in potable reuse trains. Under such conditions, chloramines are an inevitable component in the AOP feed water given their application as an antifouling agent for the upstream membrane processes. In cases when other oxidants, such as free chlorine, are to be used in the AOP treatment, the effect of background chloramines and any potential interplays between the oxidants should be considered. In this study, vacuum-UV (VUV) and VUV/Cl2 have been proposed as promising AOP alternatives for potable reuse and the effect of chloramine photolysis has been considered on the removal of 1,4-dioxane. Results indicated that while presence of chloramine reduces the treatment efficiency in the VUV AOP, coexistence of free chlorine and chloramine oxidants significantly improves 1,4-dioxane degradation rates. Experimental data and kinetic modeling both confirmed the roles of OH• and Cl2•- in 1,4-dioxane removal with 62.5% and 32.5% contribution in the VUV/Cl2/chloramines, respectively. Among the other water matrix conditions, Cl- was shown to improve the degradation rates while HCO3- suppressed the reactions by scavenging radical species. Overall, the findings of this research are informative for the design and development of VUV AOPs at small scale potable reuse facilities.

A multi-objective solution approach for the design of a sustainable and robust system of wastewater treatment plants: The case of Chile

Water use has been growing at more than twice the rate of population increase in the last century. Combined with a more erratic and uncertain supply, this will aggravate the situation of currently water-stressed regions and generate water stress in areas with abundant water resources. It presents a major challenge for climate adaptation and raises the need for new sources of water resources. The research question, then, is whether there are sustainable supply chain configurations for wastewater reuse capable of operating with frequent changes in water demand and wastewater availability. Then, a multi-objective mixed-integer linear programming (MoMILP) model to provide an explicit description of the robustness concept is formulated. To illustrate the proposal’s usefulness, the current situation in the center-north zone of Chile, where the availability and demand of water resources continue to fluctuate by natural and economic factors, is considered. The results provide five robust and sustainable supply chain configurations for wastewater reuse alternatives. They guarantee to meet the minimum demand for the resource with the amount available in any scenario. These results could be the basis for governmental policies related to tenders for wastewater reuse plant development, considering water is a common pool resource. Finally, some theoretical and practical contributions, extensions, managerial implications, and future work are discussed to develop a robust and generalized approach for the generation of public plans and policies in the design of robust and sustainable wastewater treatment plant systems.

Metabolomic Approach to Study the 'Purple Queen' Pomegranate Cultivar Response to Alternative Culture Media and Phenological Stages.

The increasingly evident threat of depletion of world peat bogs is encouraging the search for and study of alternative agricultural substrates that can fully or partially replace peat, guaranteeing food supply (quality and quantity). On the other hand, the identification of the potential for the reuse of waste from relevant economic activities has increased in recent years, mainly motivated by the change to a sustainable circular economy, as is the case of port sediments. Taking into account that significant volumes of dredged port sediments are generated annually so that ports can maintain their economic activity, it is necessary to find objective, sustainable and safe reuse alternatives. In this sense, the objective of this study was to study the response of the "Purple Queen" pomegranate when grown with dredged port sediment. For this, the fruit production (kg), number of fruits (fruits tree-1), fruit weight (g), and seed yield (%) aiming to verify the correct tree development were evaluated. In addition, a 1H-NMR foliar metabolomic study for the three most relevant phenological phases was performed (flowering, fruit development, and post-harvest) to identify metabolic changes in trees. In total, 29 metabolites were identified; among them, 11 were amino acids, 6 organic acids, 5 sugars, and 7 secondary metabolites. The good agronomical development of the trees and fruits indicated the potential for using the dredged sediment as an agricultural substrate. On the other hand, the results revealed that the greatest variability in the metabolomic study occurred between the phenological phases and a lower variability is explained by the substrates used.

Evaluation of the effects of textile fibre derived from end-of-life tyres (TFELT) on the rheological behaviour of asphalt binders

End-of-Life Tyres (ELT) consist of rubber, steel and textile fibre (TFELT). Unlike rubber and steel, the possibilities for the re-use of TFELT are limited, and its final disposal is an environmental problem. This article explores an alternative re-use of TFELT as an additive for asphalt binder (AB). The TFELT was characterised using scanning electron microscope (SEM), polarized microscopy and thermogravimetric analysis. Two Asphalt Binders (AB14 and AB24) and three addition percentages (0.1%, 0.3% and 0.5%) were evaluated. The effects on the physical properties at high, intermediate and low temperature were studied by determining the softening point, penetration and FRAASS breaking point. We also evaluated the effects on the rheological properties, by determining the rutting and fatigue parameters at different states of ageing (short and long term). Resistance to the accumulation of deformations was measured by applying the Multiple Stress Creep Recovery test (MSCR), and resistance to fatigue by the Linear Amplitude Sweep test (LAS). The results showed significant effects in reducing the accumulation of permanent deformation, by up to 40% for the addition of 0.5% TFELT, without any reduction in properties of resistance to thermal cracking.

Circular economy in biorefineries: Scale-up of anaerobic/aerobic membrane bioreactors for vinasse recycling

The increased ethanol production driven by the growing demand for biofuels have the generation of vinasse as a negative aspect. Aiming for vinasse recycling, this study compared the performance of aerobic (AeMBR) and anaerobic (AnMBR) membrane bioreactors as alternatives for water, energy, and fertilizer recovery. In terms of organic matter, the AnMBR demonstrated a better removal efficiency (RAnMBR: 97%, RAeMBR: 92%) with significant differences. Higher values of chemical oxygen demand (COD) in the AeMBR permeate were correlated with the higher production of soluble microbial products and external polymeric substances. The opposite was observed in terms of total nitrogen removal since AeMBR showed better efficiency (RAeMBR: 80%, RAnMBR: 56%). Due to the higher fouling rate, the AeMBR required a higher increase in transmembrane pressure to guarantee a constant permeate flux and more frequent interruptions for membrane cleaning and maintenance. It would be able to recover 527 m³/h of permeate to be used in cane washing procedures or as feedstock for fertilizer obtainment, the latter with the expectations of better reuse of vinasse nutrients and lower environmental impacts compared with fertigation practices. Their demand (water and fertilizer), aligned with economic aspects, should be considered when deciding on the best reuse alternative. The AnMBR presented a higher operational cost (0.515 US$/m³) compared with the AeMBR (0.441 US$/m³). Nevertheless, the system allowed to recover 6.1 Nm³-CH4/m³-vinasse, which represents an energy production potential of 26.1 kW/m³-vinasse. Overall, the systems would allow for the higher valorization of vinasse, with better use of wastes and contributing to less dependence on raw materials.

Preface

The need of the era is sustainable development. Sustainable development is the idea that human societies must live, and meet their needs, without compromising the ability of future generations to achieve their requirements. Sustainability is a multidimensional concept that requires a balance of economic, social and environmental equities of development. For engineering processes, this balance can be achieved by ensuring efficiency in resource use and by reducing the environmental impact, without ignoring the technical, technological and financial concerns related to the process. The civil engineering practitioners need to focus on sustainable development issues by emphasizing on the use of green and high-performance materials, applying research and development results timely into practical projects, thus reducing the use of raw materials in manufacturing, as well as treating the waste causing adverse impact on the global environment. In this context, the research studies on sustainability related issues, e.g. (i) application of alternative materials, (ii) material reuse and recycling, (iii) development of environmentally friendly techniques, (iv) efficient use of the space, (v) reuse of structures or its components, could provide good solution. Sustainable development study of civil engineering can guide in actively choosing and taking appropriate measures in construction stage according to the on-site conditions to reduce adverse effects to ecosystem, reducing the inconvenience and trouble to the nearby, and using scientific methods to strengthen the management of construction workers and improve their safety awareness. Our special thanks go to IOP Publishing (IOP Conference Series: Materials Science and Engineering) as our publication partner to publish this volume of conference proceeding of SDCEE-2021, the 1st International Online Conference on Sustainable Development in the areas of Civil Engineering and Electrical Engineering, entitled Sustainable Development in Structural & Transportation Engineering in their prestigious IOP Conference Series. The book covers a variety of multidisciplinary chapters, which would prove to be useful to students, working professionals, practitioners and researchers. List of Conference or Sponsor Logo, List of Committees are available in this pdf.

Dredged Material Decision Tool (DMDT) for Sustainable Beneficial Reuse Applications

The Dredged Material Decision Tool (DMDT) was developed by the United States Environmental Protection Agency (USEPA) to allow project managers, stakeholders, and communities to quantify environmental, economic, and social considerations of using dredged material for beneficial purposes. Dredged material may be disposed in a confined disposal facility (CDF); however, this option is unfavorable because of the finite capacity problems these facilities pose. A more sustainable option is to use dredged materials beneficially such as construction material, for habitat restoration, or for brownfield remediation projects. This study demonstrates the applicability of the DMDT to three relevant candidate projects: (1) Dog Beach, Greenwood, and Lee Street Beaches (Evanston, IL, USA); (2) New York-New Jersey Harbor (New York/New Jersey); and (3) Poplar Island (Chesapeake Bay). The DMDT requires the project information and then completion of worksheets with each criteria (biophysical environment, economic, governance, social, and built environment) ranked, weighed, and scored. The DMDT is applied for all potential alternatives and the results are then analyzed to select the best beneficial reuse alternative. It was found that for the beaches in Evanston, the most beneficial option was on-beach placement with hydraulic dredging. The best option for the New Jersey Harbor was found to be using for brownfield and landfill remediation. The best option for Poplar Island was the lateral and vertical expansion of 50% uplands and 50% wetlands. Overall, DMDT is found to be a valuable tool to facilitate the evaluation of multi-criteria based on the project-specific data and help select the best beneficial use alternative for the dredged material.

Green and circular procurement in public organizations – from single use to reuse and prolonged lifetime in the City of Malmö

The procurement in public organisations has traditionally been performed in a linear way. Using circular solutions could help public organisations to save resources and tackle climate change. The Swedish City of Malmö strives to include circular solutions and become a circular municipality. The goal of the study was to explore activities for increased reuse and visualise how circular material flows can reduce environmental impacts. The goal was also to develop a method for mapping material flows that can be used in the City of Malmö and other public organisations. The studied activities included in this study are the reuse of furniture and replacement of single use plastic with reuse alternatives, as well as prolonged lifetime of IT products and textiles. Life cycle analysis (LCA) based methods were used to estimate the reduction in environmental impact from the studied activities. The perception of circular activities within the City of Malmö was analysed with a survey. The results showed that the purchasing agreements with increased lifetime for clothing and IT products, lead to reduced environmental impacts. The results also showed that most employees are interested in using a digital sharing platform. Additionally, the results pointed out the need for a circular manager.

Architectural technologies for life environment: Spent coffee ground reuse in lime-based mortars. A preliminary assessment for innovative green thermo-plasters

Spent coffee ground, the residue obtained from the brewing process, is the primary unavoidable (inedible) waste from the coffee consumption. As coffee production and beverage consumption are increasing worldwide, a more sustainable waste management is required since the usual disposal in landfill is a liability to both humans and the environment. This paper is aimed at showing a possible alternative reuse of coffee ground wastes in novel green building materials intended for thermo-plastering applications in construction, in a circular economy context. Coffee waste was used in various percentages (up to 17.5%) to assess the engineering performance of the produced bio-composite mortars. The main results showed that just a little amount of coffee waste determines a bulk density decrease up to 15.4% (making the products comparable to a structural lightweight conglomerate or a light plastering mortar), an extensive drop in mechanical performance (still maintaining acceptable values for the considered plastering application) and in thermal conductivity (up to 47%). Moreover, a multi-criteria analysis, not only able to consider the materials performance, but also aspects related to the environmental impact and the economic drawback, has been implemented resulting that the preferable mix would contain 10% waste. Finally, preparatory virtual energy simulations were implemented to analyse the performance of that mix in a simplified architectural model, revealing a sufficient energy improvement and a more efficacy in cold climates. All considering, coffee waste can be effectively reused to manufacture green bio-composite thermo-plasters with adequate energy performance considering the main requirements of a building application.

Mechanical and fracture behaviors of compacted gold mine tailings by semi-circular bending tests and digital image correlation

The storage and handling of mine tailings (MTs) pose significant economic and environmental problems and finding suitable recycling or re-use alternatives for MTs is an on-going process. One of those alternatives is creating MTs-based adobes or compacted MTs, which then can be used in construction materials and ground stabilization applications Therefore, the fully understanding of the mechanical and fracture behaviors for the compacted MTs are significant for the applications. However, no study on such behaviors of the compacted MTs was documented in the literature. In this study, the investigations of the mechanical and fracture behaviors of the compacted MTs were carried out experimentally by using semi-circular bending tests (SCB) and digital image correlation (DIC). The SCB tests were conducted by using three-point bending instruments. Mode I fracture behaviors were therefore obtained by manually setting different notch depths with various loading span distances. The influences of notch depths and span distances on the Mode I fracture toughness, KI, were obtained by testing the notched SCB specimens. Additionally, the influences of notch depths and span distances on the fracture process zone (FPZ) and fracture energy were evaluated. Results showed that the measured Mode I fracture toughness was not evidently influenced by the notch depths and span distances. The fracture energy decreased with the increase of notch depth and span distance. Finally, the maximum major principal strains were found to increase with the increase of notch depths.