Increasing the use of wood as a construction material and implementing circular economy principles are possible ways of reducing the environmental impact of the building construction sector. However, with an increasing use of timber and mass timber products in buildings, the amount of wood production waste is increasing as well. Wood production waste is typically downcycled and not considered as a resource for construction. This is particularly questionable in the case of Cross-Laminated Timber (CLT). Compared to other types of engineered wood products, its production requires large amounts of raw material and results in large amounts of waste. In contrast to downcycling, upcycling CLT production waste bears the promise of preserving or even increasing the material’s value, which makes it economically more compelling. In this paper, we present a prototypical computational design and digital fabrication workflow that enables the use of CLT production waste in prefabricated assemblies, potentially to be used as wall or façade elements, ideally with modular qualities. We elaborate on how the application of this workflow enabled the design and construction of a full-scale demonstrator, which serves as a proof-of-concept, and share insights gained during and after its construction. Finally, the paper provides an overview of possible applications and discusses the adjustability of the workflows for other design principles and construction systems.
This study investigates self-reported associations between colour and visual perception in a high-circulation public space on a university campus. Focusing on attributes including attention, visibility, perceived safety, aesthetic contribution, mood, and perceived wayfinding effectiveness, it explores how different colour alternatives are perceived across a set of everyday spatial-experience criteria, with the aim of informing evidence-based colour-design discussion rather than establishing causal or behavioural claims. The empirical study involved 151 undergraduate students from the Department of Interior Architecture at Istanbul Aydın University. The investigated setting was the heavily used outdoor circulation area known as the Blue Stairs. The theoretical framework draws on colour-in-context theory to examine associations between warm, cool, and neutral colour alternatives and users’ self-reported perceptual responses. Data were collected through an online, image-based questionnaire in which participants viewed eight digitally simulated colour alternatives of the staircase and, for each of eleven perceptual attributes, selected the single colour alternative they associated most strongly with that attribute—a categorical, forced single-choice design rather than an independent rating of each colour. Responses were analysed using descriptive statistics, chi-square goodness-of-fit tests, Cohen’s w effect-size estimation, Correspondence Analysis, and Hierarchical Cluster Analysis to explore patterns of association between colour and perceptual attribute. The findings indicate that no single colour was selected consistently across all criteria; instead, different colours were associated with different perceptual attributes. Correspondence analysis positioned red and purple, as an exploratory aggregate-level pattern, closer to attention and visibility, and blue, grey, and green closer to perceived safety, aesthetic contribution, and harmony with surroundings. A complementary hierarchical cluster analysis, with cluster number compared via silhouette coefficients across k = 2–7, found that the two-cluster solution—separating red from the remaining seven colours—achieved the highest silhouette coefficient (0.313), although overall cluster separation was modest. Taken together, these exploratory analyses suggest that the observed colour-selection patterns are structured rather than randomly distributed across perceptual attributes, and that colour may be a useful evidence-informed design variable, offering architects and designers a data-informed starting point for colour strategies in campus circulation spaces and comparable public environments.
PurposeThis study assesses the significance of risks associated with integrating Generative Artificial Intelligence (GenAI) into risk management for sustainable construction projects (SCPs). Given the early stage of GenAI adoption in the construction sector, the study adopts an exploratory approach to evaluate how industry professionals perceive the efficacy and preparedness of existing risk management (RM) practices in addressing emerging GenAI-related risks. It also proposes response strategies to mitigate their potential impacts.MethodologyThe research followed a five-stage methodology. First, a systematic literature review (SLR) identified and classified GenAI-related risks. Second, a multi-criteria assessment model was developed to evaluate risk significance and the perceived efficacy of RM practices in addressing these emerging risks. Third, a structured survey involving 80 construction experts provided input data for the developed assessment model. Fourth, a fuzzy-based model was developed to quantify the perceived level of RM practice efficacy in relation to GenAI-related risks. Finally, a semi-structured expert survey identified best-practice response strategies for each risk category.FindingsThe study identified 30 risk factors grouped into five categories: input quality, technological adaptability, ethical and governance, information integrity, and financial risks. The results indicate a generally low-to-medium level of perceived preparedness of current RM practices in addressing GenAI-related risks. This finding suggests that existing RM structures may not yet be fully equipped to manage the complexities introduced by GenAI, particularly within the fragmented, multi-stakeholder, and sustainability-driven context of SCPs. Best-practice strategies were also identified for each risk category.ImplicationsThe study presents an integrated RM assessment model positioned as an early-warning tool for evaluating organisational preparedness for GenAI integration in SCPs. It identifies gaps in perceived RM efficacy, highlighting the need for targeted mitigation strategies. The proposed response strategies offer practical guidance for improving resilience and readiness in SCPs while considering sector-specific challenges such as temporary project organisations, regulatory demands, and lifecycle sustainability requirements.Originality/ValueThis study is among the first to assess GenAI-related risks in RM for SCPs using fuzzy logic. It adopts an anticipatory and perception-based approach suited to early-stage adoption rather than evaluating mature implementation. The findings highlight gaps in perceived RM preparedness and provide sector-specific insights that support more effective and responsible GenAI integration in sustainable construction.
Oil and gas construction projects (O&GCPs) are among the most complex and high-stakes endeavors in the world. In the UAE, these projects operate under demanding safety and regulatory environments, yet persistent risk-related disruptions continue to undermine project performance. Existing risk management frameworks rarely integrate prioritization with mitigation strategy evaluation, leaving practitioners without structured guidance under conditions of uncertainty. This study addresses that gap by developing a hybrid Delphi–Fuzzy Analytic Hierarchy Process (FAHP) framework for UAE O&GCPs. A systematic literature review identified 51 candidate risk factors, of which 32 organized across six categories achieved expert consensus through a two-round Delphi process involving ten UAE-based industry professionals. FAHP was subsequently applied to derive priority weights for each risk dimension and associated mitigation strategies. Results reveal a strongly hierarchical risk structure in which health, safety, and workforce wellbeing emerged as the dominant criterion with a weight of 0.502, followed by regulatory and site risks at 0.266, while financial factors ranked lowest. Alignment with Health, Safety, and Environment (HSE) standards emerged as the single most critical mitigation sub-criterion, confirming that safety compliance drives project continuity in this sector. These findings provide practitioners with a prioritized, evidence-based roadmap for allocating resources and designing mitigation strategies in UAE O&G construction.
As climate change drives global sea-level rise, coastal regions are increasingly vulnerable to compound hazards in which elevated baseline sea levels and tidal conditions can significantly amplify tsunami-induced inundation. This study quantitatively evaluates the impacts of sea-level rise (SLR) and tidal conditions on tsunami inundation in the Ise and Mikawa Bays in Japan using an integrated numerical framework consisting of JAGURS for tsunami propagation and SuWAT for inundation. Simulations were conducted under the 2050 SLR projections (+0.2 m and +0.5 m, SSP2-4.5), the annual maximum high-tide levels observed in 2012 (T.P. +1.29 m at the Port of Nagoya; T.P. +1.21 m at the Port of Mikawa), and the 185-day normal discharge for each target river. The results indicate that the influence of river discharge is negligible compared with the dominant effects of SLR and tides. In the inner Ise Bay, characterized by extensive low-lying plains, the combined effects of high tide and +0.5 m SLR increase the inundation area to 337% of the baseline. Mikawa Bay shows a similar vulnerability, with the inundation area increasing by a factor of 5.1 under high-tide conditions compared with the mean sea level. SLR increments from 0 m to 0.9 m were examined, and the results demonstrate an exponential increase in the inundation area with SLR magnitude in both bays. Regression analysis indicated that the nonlinear mechanism of inundation expansion—driven by levee overtopping and inflow into low-lying basins—is topographically robust across bay geometries. These findings indicate that future SLR may normalize extreme inundation risks previously associated with high-tide events. The developed empirical regression models provide a practical tool for rapid estimation of the extent of inundation without the need for exhaustive recomputation. The study offers guidance for revising coastal disaster mitigation strategies, evacuation planning, and reassessing infrastructure design standards in response to climate-driven environmental changes.
This study examines the complex three-dimensional (3D) air-water flow characteristics in a chute spillway using Ansys Fluent for numerical simulations. The Volume of Fluid method incorporating a dispersed interface and Large-Eddy Simulation was evaluated along with the Renormalization Group k-ε model for comparative analysis. Based on available experimental data, the numerical model was validated using two structured grids: Uniform Structured Mesh (USM) and Locally Refined Structured Mesh (LRSM). The approach velocity was v = 6.831 m/s, corresponding to a Froude number of 7.525 and a Reynolds number of 1.313 × 106, measured upstream of the aerator. The analysis was conducted in two stages: (i) an assessment of mesh refinement and (ii) an evaluation of LES sub-grid-scale (SGS) models. The numerical results demonstrate that both procedures reproduce the general trends of flow pattern, jet length, velocity, and pressure along the chute. However, pronounced differences arise in the prediction of air concentration within the cavity and reattachment zone. Among the investigated approaches, the Locally Refined Structured Mesh coupled with SGS models provides better agreement with experimental results, capturing flow patterns, pressure distribution, air concentration in the cavity, and the downstream region with reasonable accuracy. The Uniform Structured Mesh and RNG k-ε exhibit larger deviations in terms of flow pattern, velocity, pressure, and air concentration. The findings demonstrate that aerated spillway flow predictions are more sensitive to grid resolution than to SGS modelling configurations.
Carbonic anhydrase (CA) catalyzes the hydration of CO2 to HCO3− at rates that could enhance the carbonation of the calcium hydroxide reservoir in cement-based binders. In practice the reported magnitude of this enhancement varies considerably among the few studies that have examined it, and the procedures for translating raw thermogravimetric (TG) mass-loss measurements into reported “equivalent CaCO3” contents are rarely stated explicitly. Here we report a preliminary TG-based comparison between portland cement pastes hydrated for 3-7 days with: (i) no enzyme, (ii) CA, and (iii) cross-linked enzyme aggregates of CA (CLEA-CA), at CO2 concentrations from 0.04% to 1.0%. Equivalent-CaCO3 content is computed by an explicit tangent-line construction on the TG curve that excludes the C-S-H bound-water background; this method gives roughly half the values of an endpoint-difference method that omits baseline subtraction. We find that CA does not enhance CaCO3 formation in cement paste at any of the CO2 levels studied, while CLEA-CA produces a clear enhancement (+20% over the enzyme-free control) at the highest CO2 concentration (1.0%); the enhancement at lower CO2 is weaker and non-monotonic. The data are consistent with the hypothesis that CLEA-CA are more stable and enable measurable product formation in the high-pH, mass-transfer-limited cement matrix. The result motivates additional engineered-CA work to extend this enhancement to atmospheric-CO2 curing conditions.
Accurate identification of hydrodynamic characteristics for wave energy converters is a prerequisite for designing effective control strategies and power-optimization models. The identification could, in principle, be based on physical model experiments. However, in practice, mechanical imperfections, particularly Coulomb friction at pile-hinge connections, introduce a non-sinusoidal force component that contaminates the measured signals and yields spurious values of added mass and radiation damping coefficients. Those coefficients are the cornerstone for a power optimization study for the next stages. This paper presents a method to identify and quantify the dissipation contribution due to mechanical limitations by performing forced-oscillation tests on a 1:20-scale rectangular-shaped floating breakwater wave energy converter with a moonpool, tested in the wave flume lab of the University of Padova at different frequencies and amplitudes. Dry condition tests, carried out with and without the friction due to the pile constraints, characterize the mechanical dissipation and spurious dry stiffness independently of any hydrodynamic effects. Tests in water (wet tests) for both heave and pitch degrees of freedom are used to identify hydrodynamic characteristics contaminated by the square-like component due to friction. Overall, the procedure enables the acquisition of corrected force signals to better identify hydrodynamic characteristics (added mass, radiation damping, and frequency response function).
IntroductionMass housing has emerged as a pragmatic response to address the increasing housing demand of India’s growing population. However, its predominantly Western design paradigm often overlooks the diverse cultural practices and lifestyles of residents, resulting in cultural alienation, loss of identity, and reduced inclusivity. Although previous studies have primarily focused on the environmental, economic, and functional performance of housing, limited attention has been given to integrating cultural sensitivity into mass housing design. This study investigates how the spatial and architectural characteristics of Chettinad vernacular architecture can be adapted to contemporary mass housing to promote culturally inclusive residential environments.MethodsThe study adopted a mixed-methods research approach combining qualitative and quantitative techniques. Comparative case studies of traditional Chettinad ancestral houses and contemporary housing developments were undertaken alongside questionnaire surveys involving Chettiar respondents residing in India and abroad. The culturally significant architectural and spatial elements identified through the qualitative phase were prioritised using the Analytic Hierarchy Process (AHP) to determine their relative importance and feasibility for integration into mass housing.ResultsThe AHP analysis identified courtyards and pillars as the highest-ranked cultural elements, suitable for incorporation within shared and community spaces of apartment developments. At the dwelling-unit level, Athangudi tiles, wood craftsmanship, and dedicated pooja rooms emerged as culturally significant elements that can be realistically integrated without compromising spatial efficiency. The findings demonstrate that vernacular design principles can be systematically translated into contemporary housing through interventions at both the building-block and individual-unit scales, thereby enhancing cultural identity while maintaining functional requirements.DiscussionThe study provides a transferable framework for integrating vernacular architectural values into mass housing through context-sensitive and participatory design strategies. By aligning with Sustainable Development Goal (SDG) 11, the proposed framework contributes to the development of culturally inclusive and socially sustainable housing. Although the research focuses on the Chettinad community, the methodology and design framework can be adapted to other regions with comparable socio-cultural traditions, vernacular architecture, and family-oriented lifestyles, thereby supporting broader applications in culturally responsive housing design.
IntroductionOpen concrete channels in Andean watersheds convey irrigation water and urban stormwater, and their deterioration raises Manning’s roughness coefficient (n), alters specific energy (E) and consumes freeboard. Managers know that a channel is degraded but lack a reproducible procedure for turning that observation into a defensible intervention priority.MethodsWe characterise ten consecutive reaches (219 m) of a rectangular cyclopean-concrete channel in Ambato, Ecuador (b = 0.645 m; Q = 0.21 m3/s; s0 ≈ 0.03). Each reach was scored on a 1–5 Structural Damage Index and mapped to a Manning coefficient through an additive decomposition reported reach by reach. The coefficients were propagated through the Manning–Strickler equation, solved simultaneously with continuity, to obtain normal depth, velocity, Froude number, specific energy and freeboard. Because these quantities are deterministic functions of the assigned n, they are reported as transfer curves rather than as statistical relationships; analysis is confined to the observations themselves and to the propagation of observer uncertainty.ResultsAssigned coefficients ranged from 0.016 to 0.034, that is 23%–162% above the design value of 0.013. Departure of specific energy from the design condition ranged from 14.5% to 30.9%, and freeboard fell from 0.277 m to 0.160 m in the most degraded reach, a loss of 42% of the original margin. The transfer curve is not monotonic: the departure peaks near n ≈ 0.030 and declines beyond it, because specific energy passes through its minimum at the critical regime, reached here at n ≈ 0.0304. A one-class error in visual scoring displaces the departure by 8.6 percentage points on average and would change the intervention tier of six of the ten reaches; the two requiring immediate intervention are not among them.ConclusionStructured visual assessment combined with transparent hydraulic propagation yields a traceable intervention hierarchy reproducible with a camera, a total station and an open-source solver. The hydraulic values are model-derived estimates conditional on the assigned coefficients, not measurements; calibration against in situ measurement remains necessary and generalisation beyond this channel is not demonstrated. The protocol, imagery and scripts are released as an openly licensed dataset intended as ground truth for future classifiers.
IntroductionThis study exposes systemic challenges affecting structural masonry performance, including skills shortages, material non-compliance, regulatory fragmentation, supervision practices and sustainable construction governance in South Africa. Structural masonry remains one of the most fundamental building technologies globally, particularly within developing economies. However, its quality and efficiency have been challenged by material deficiencies, inadequate training, lack of supervision and poor adherence to standards. The pursuit of improved structural and production efficiency in masonry is imperative for ensuring durability, sustainability and cost effectiveness in construction.MethodsThe study develops a socio-technical framework explaining how governance fragmentation, declining workforce capability and inconsistent technical compliance collectively shape masonry performance. Interview data collected from industry specialists using a semi structured approach are used in the analysis to highlight the congruences and incongruences between the theoretical arguments and real world industry practices.ResultsThis study provides an integrated framework, taking into account technical, human and organisational considerations, which would facilitate compliance, innovation, quality assurance and human capability in structural masonry. The findings indicate that structural masonry inefficiency emerges through reinforcing interaction between institutional fragmentation, declining human capability and inconsistent technical compliance systems.DiscussionThe study contributes an integrated socio-technical systems framework for analysing structural masonry transformation within developing construction environments.
Reinforced concrete (RC) moment-resisting frames (MRFs) equipped with steel damper columns (SDCs) are damage-tolerant structural systems in which seismic energy is primarily dissipated by the damper panels in the SDCs. An energy-based limit-curve framework using cumulative input energy and maximum momentary input energy was previously developed for these systems, but it was limited to the initial, undamaged state. After prior seismic damage, residual capacity may depend on both peak deformation and cumulative loading history. This study proposes post-damage energy-based limit curves for earthquake-damaged RC MRFs with SDCs. Damaged states are defined using the Extended Critical Pseudo-Multi Impulse Analysis in terms of the peak story drift and the number of pseudo-impulsive lateral forces during the first multi-impulsive input (MI). The results show that the post-damage limit curves lie inside the corresponding initial-state limit curves, with greater degradation for larger peak deformation and more extensive cyclic loading during the first MI. Furthermore, the residual ratios of the post-damage limit curves decrease as the number of pseudo-impulsive lateral forces in the second MI increases. These findings demonstrate that, for the RC MRFs with SDCs examined in this study, post-earthquake residual seismic capacity should be evaluated using an energy-based framework that considers both the damaged state and the subsequent input.
IntroductionIn hyper‐dense cities such as Hong Kong, unequal access to essential amenities has important implications for social equity, particularly within the public housing sector. However, accessibility differences between Public Rental Housing (PRH) and Home Ownership Scheme (HOS) estates have rarely been examined from both multimodal travel‐time and network‐structural perspectives.MethodsThis study examined 147 public housing estates in Kowloon, including 82 PRH and 65 HOS estates, and assessed access to five categories of public medical and educational facilities: general outpatient clinics, hospitals, specialist outpatient clinics, public primary schools, and public secondary schools. Travel times by driving, public transit, and walking were obtained from the Google Maps Distance Matrix API on weekdays in February 2025. Estate‐level accessibility was measured using average travel time to retained facilities, PRH‐HOS differences were tested statistically, and GIS‐based Kernel Density Estimation and Gephi network analysis were used to assess spatial concentration, closeness centrality, modularity, and network density.ResultsPRH estates had modestly but significantly longer driving times than HOS estates. Across all key facilities, the mean driving time was 0.47 min longer for PRH estates, corresponding to a 5.1% increase. Public-transit differences were generally small and non-significant, whereas walking differences varied by facility type. PRH estates also showed lower average closeness centrality (0.38 versus 0.52) and lower network density (0.22 versus 0.35), while the overall modularity score of 0.62 indicated distinct accessibility communities.DiscussionAccessibility inequality within Hong Kong’s public housing sector is mode‐ and amenity‐specific and is reflected not only in travel‐time differences but also in the structural positions of estates within the housing‐amenity network. The findings support targeted amenity allocation, transit and pedestrian improvements, and accessibility‐sensitive planning for existing and future public housing estates.
Seasonal freeze–thaw (F–T) cycles pose significant challenges to the structural performance and long-term durability of road infrastructure in cold regions. Repeated freezing and thawing lead to frost heave, thaw weakening, and subgrade strength loss, often resulting in rutting, potholes, and premature pavement deterioration. Geosynthetics, including planar systems such as geotextiles, geogrids, and geomembranes, as well as three-dimensional systems such as geocells, have increasingly been adopted in transportation infrastructure to improve pavement stability and extend service life. This paper presents a comprehensive review of the state of the art and current practices of geosynthetic applications in cold-region pavements subjected to seasonal freeze–thaw cycles. The review synthesizes findings from field investigations, long-term pavement monitoring, laboratory testing, and numerical modeling studies. Results from experimental studies generally indicate that geosynthetics can enhance pavement performance, although the magnitude of improvement varies depending on soil conditions, moisture content, and reinforcement types. However, most of the existing numerical models and pavement design frameworks do not explicitly incorporate freeze–thaw processes or temperature-dependent soil–geosynthetic interface behavior. Current pavement design frameworks, including the AASHTO 1993 Guide for Design of Pavement Structures and its subsequent Mechanistic–Empirical Pavement Design Guide (MEPDG), along with the United States Army Corps of Engineers (USACE) and Transportation Association of Canada (TAC) guidelines, provide limited integration of geosynthetic reinforcement with seasonal variations in soil properties. The review highlights the need for more climate-responsive design parameters and standardized frameworks that incorporate freeze–thaw effects to enable reliable and sustainable use of geosynthetics in cold-region transportation infrastructure.
In educational institutions with the use of mechanical ventilation especially in arid climates indoor air quality (IAQ) has significant implications to health and cognitive performance of occupants. The present study examined 35 different sites’ IAQ at Abu Dhabi University, United Arab Emirates (UAE), in January-February 2024 comparing the observations with 2024 IAQ Guideline in Dubai Municipality (DM-HSD-GU119-IAQ). Portable instruments were used to measure eleven parameters: temperature, relative humidity, CO2, CO, ozone, formaldehyde, total volatile organic compounds (TVOC), PM10 and PM 2.5. The count of viable bacteria and fungi was determined by 15-min passive sedimentation on agar plates (incubated 5 days at 25 °C ± 2 °C; transformed to cfu/m3 using the standard sedimentation formula). This settle-plate approach measures microbial deposition under passive settling conditions. Quality control included daily zero checks, duplicate measurements at approximately 10% of sampling locations (coefficient of variation <12% for gases and <18% for particulate matter), and gravimetric correction of particulate matter measurements. Overall the permissible standards were met at the majority of locations, exceedances occurred at a total of eight locations across four parameters which includes CO2 (>800 ppm; max 1,093 ppm) at five high occupation sites (Finance Department, male reading area, three classrooms/dormitories), formaldehyde (>0.08 ppm; 0.10 ppm) at the main auditorium, total bacterial count (>500 cfu/m3; 1,259 cfu/m3) at a male dormitory, and total fungal count (>500 cfu/m3; 1,259 cfu/m3) at a female dormitory. The remaining parameters were in full compliance. These findings represent a single-round screening assessment rather than a comprehensive exposure evaluation. Hotspots indicate poor ventilation, off-gassing of the material, and proliferation of the microorganisms based on moisture. Sustainable IAQ can be achieved through targeted interventions such as demand-controlled ventilation, furnishings with low emissions, and the remediation of moisture and HVAC of dormitories, which become viable avenues to sustainable IAQ.
IntroductionA meaningful reduction of carbon emissions in Canada’s Architecture Engineering Construction, Owner, and Operator (AECOO) industry must incorporate strategies for both new and existing buildings. In the case of existing buildings, Deep Energy Retrofits (DERs) have proven to be an effective solution—reducing energy consumption by a minimum of 50% through improvements to the building envelope and mechanical systems. Exterior overcladding DER approaches require accurate documentation of the building exterior to support the reconciliation of existing conditions with the requirements of new construction. However, as-found records of buildings are often incomplete or inconsistent.MethodsThis review outlines the building documentation methods and techniques found in existing DER literature and supplements it with literature on documentation methods and techniques from other disciplinary contexts that can be applied to retrofit use-cases. The review follows the PRISMA–ScR protocol and includes 109 cross-disciplinary sources gathered through two searches of ten databases. The review is limited to open-access publications written in English. The sources include both journal articles and conference papers spanning fourteen years, and fall into four main categories: review papers, building documentation case-studies, method evaluations, and method developments.ResultsThese sources demonstrate that topographic survey, laser scanning, photogrammetry, thermal imaging, and ground-penetrating radar collectively provide geometric, thermal, and subsurface data advantageous to DERs. Multi-sensor hybrid workflows consistently outperform single method approaches in area covered, accuracy, and information richness.DiscussionHowever, cross-disciplinary digital recording of the built environment operates without a shared vocabulary, common methodologies, and consistent reporting standards. This makes it difficult to extract transferable standard practices from the existing literature. This scoping review contributes a mapped and synthesized cross-disciplinary landscape of building documentation methods applicable to DER use-cases, and the identification of its most consequential gap: a validated, DER-specific framework that connects method selection and data acquisition planning to defined accuracy thresholds, Level of Detail (LOD) specifications, and the outputs required for retrofit design, fabrication, and assembly.
The construction sector is a major contributor to environmental degradation, with cement manufacturing accounting for a significant portion of global CO2 emissions. This study explores the partial replacement of cement with reclaimed asphalt pavement (RAP) powder as a sustainable alternative to conventional concrete production, a strategy that remains relatively underexplored in literature. Concrete mixes containing 2.5%, 5%, 7.5%, and 10% RAP powder replacing cement by volume were designed accordingly. The tarantula curve methodology was adopted to optimize aggregate gradation enhancing mix performance. Mechanical properties, including compressive, flexural, and tensile strengths, alongside workability and durability, were evaluated. Exploratory models were developed to examine the relationship between RAP content and compressive strength with flexural strength, tensile strength, and elastic modulus. Thermogravimetric analysis (TGA) indicated negligible pozzolanic activity of RAP powder of 8%. However, the results indicate that at 5% RAP replacement, the concrete achieved mechanical performance comparable to that of the control mix (0% RAP) suggesting a useful micro filler effect at his level. A Cradle-to-Gate Environmental Assessment using a 1 m2 concrete slab functional unit showed that replacing 5% and 10% of cement with RAP powder reduced CO2 emissions by 4.85% and 9.69%, and embodied energy by 4.72% and 9.29%, respectively. Environmental benefits stem mainly from reduced cement production emissions.
Structural optimization can reduce material use and embodied carbon in reinforced concrete (RC) beams, but the removal of concrete creates truss-like load paths in which local joint behavior may strongly influence stiffness, force redistribution, and failure development. This study investigates the mechanical behavior of joints in reinforced concrete truss-like beams and evaluates how different joint geometries influence the transfer of moment, axial force, and shear between connected members. The research combines experimental testing, calibrated nonlinear finite element analysis (FEA), and isolated joint simulations. Two beam configurations, namely, Warren truss with 45° diagonals (W45) and Warren truss with verticals and 45° diagonals (W45-V), were tested under three-point bending and used to calibrate the numerical models. The calibrated FEA approach was then extended to four truss-like configurations: W45, Warren truss with 60° diagonals (W60), W45-V, and Pratt truss with 45° diagonals (P45). In addition, 66 isolated joint models were analyzed using unit rotation, axial displacement, and shear displacement to quantify moment, axial-force, and shear transfer between connected members. The results show that the investigated joints behave nonlinearly and asymmetrically, with clear stiffness changes after cracking. None of the joints behaves as an ideal hinge; instead, all configurations transfer moments, axial forces, and shear through semi-rigid joint action. W60 shows a stiffer and more direct force-transfer mechanism, W45-V provides improved redistribution through vertical members, and P45 exhibits the strongest directional dependence. Overall, member-only verification is insufficient, and simplified design should include semi-rigid joint behavior and local joint verification.
IntroductionThis study examined emerging risk factors affecting real estate development delivery in Accra, Ghana, focusing on economic, institutional, market, and environmental risks. The study was motivated by the increasing complexity of real estate development environments in emerging economies, where project performance is shaped by interconnected structural uncertainties beyond traditional construction risks.MethodsA quantitative research design was adopted. Data were collected from 98 real estate development and construction professionals, including architects, civil engineers, quantity surveyors, project managers, contractors, and estate surveyors, using structured questionnaires. Data were analyzed using descriptive statistics, reliability analysis, exploratory factor analysis, Spearman correlation, one-sample mean tests, and multiple regression analysis.ResultsThe findings showed institutional risks were the most critical, indicating governance and regulatory inefficiencies are the main challenges in Ghana’s real estate sector, followed by economic, market, and environmental risks which also contribute to uncertainty. Respondents rated all risk dimensions above the neutral midpoint, showing emerging risks are widely perceived as significant and persistent, while development performance was rated below the midpoint, indicating weak outcomes. One-sample tests confirmed risk levels are higher than expectations, while performance is lower. Factor analysis showed risks form a single interconnected system rather than independent factors. Correlation results indicated that higher risk levels are strongly associated with lower development performance. Regression analysis confirmed all risk dimensions significantly reduce performance, with institutional risk having the strongest effect.DiscussionThe study concludes that emerging risks operate as an integrated systemic structure that significantly constrains real estate development delivery performance in Ghana.
