Introduction/ObjectiveConstruction is one of the riskiest industries across the world, especially in emerging economies with poor health and safety (H&S) legislation and enforcement compared to fast-track infrastructure development. The present H&S management standards in such environments can be fragmented, causing unabated avoidable occupational hazards that result in inferior project performance. This research article aims to fill existing systemic gaps in H&S management by developing a comprehensive, context-specific framework that can shift atomized practices to an integrative safety culture. MethodsBased on a systems thinking (ST) perspective, this research adopts a mixed-design method involving induction analysis and deduction model development. This also enables the creation of a comprehensive H&S architecture that maps the relationships between risks and organizational interfaces throughout the project's life cycle. (This model was empirically founded on data collected in the Kurdistan Region of Iraq). ResultsThe proposed framework offers a holistic, dynamic H&S performance management system that is about more than just compliance. It clearly identifies the roles, obligations, and desired outcomes of all stakeholders- from government officials to site operators - throughout every step of the project development process. The structure of the framework was confirmed using a two-stage process, including type Exploratory Factor Analysis (EFA) and expert qualitative interviews. DiscussionThis proposed framework is a feasible, logical approach to reducing job hazards while promoting employee health and contributing toward building an enduring culture of safety in construction. ConclusionBy orienting local site actions with universally applicable standards (e.g., WHO guidelines), the framework may provide project managers, decision-makers, and site managers with a systematic method for integrating safety into project completion, thereby guaranteeing regulatory approval and the sustainability of projects across emerging markets. This contrasts with generic global frameworks, and this paper explicitly incorporates the ‘institutional void’ and ‘regulatory weakness’ of the Kurdistan Region, and hence serves as a baseline for future empirical on-site testing.
IntroductionIn recent years, alongside natural disasters such as earthquakes, unsafe construction practices have contributed to a rise in incidents in Iran. Adherence to building codes and safety standards is crucial for mitigation. This Delphi study in Kerman Province identifies challenges in monitoring the implementation of construction laws and regulations. Materials and MethodsA qualitative approach using the three-round Delphi method was employed with 30 experts (≥10 years’ experience). Round 1: Open-ended questionnaire responses were thematically analyzed (Cohen’s Kappa = 0.82). Round 2: Experts ranked 21 identified challenges on a 5-point Likert scale. Round 3: Results (means/SDs) were reviewed for consensus (≥75% agreement). Data were analyzed via MAXQDA and SPSS v26. ResultsChallenges were categorized into supervisors (11 subcategories) and tools/interactions (10 subcategories). Top priorities included multiple authorities in construction (mean = 4.7, SD = 0.3, 90% agreement) and imbalance between violation benefits and fines (mean = 4.6, SD = 0.4, 85% agreement). DiscussionThese systemic issues, driven by urban growth, inadequate oversight, and inter-ministerial coordination gaps, align with global studies on weak enforcement and training deficits, highlighting institutional fragmentation and incentive misalignments as key barriers to regulatory compliance. ConclusionRecent disasters, such as Metropol Abadan (2022 collapse: 41 deaths due to non-compliance) and Plasco (2017 fire: 22 deaths from outdated practices), underscore the urgent need to address these challenges through unified oversight and incentives to enhance disaster-resilient practices.
IntroductionPavement rehabilitation faces increasing challenges from aging infrastructure, moisture damage, and traffic-induced fatigue. Cold In-Place Recycling (CIPR) provides a sustainable solution by reusing reclaimed asphalt pavement (RAP) and reducing reliance on virgin materials. MethodsThis study evaluated the compressive strength of CIPR base mixtures composed of crushed aggregate (CA) and RAP stabilized with Ordinary Portland Cement (OPC), ground coal bottom ash (GCBA), and calcium chloride (CaCl2). Three CA-RAP ratios (CA75RAP25, CA50RAP50, and CA25RAP75) were tested, with total stabilizer content fixed at 4% and CaCl2 varied from 0% to 3% of the total dry weight of the CA-RAP mixture. Unconfined Compressive Strength (UCS) tests were conducted at 1, 3, 7, 14, and 28 days to assess strength development. Response Surface Methodology (RSM) was employed to model and optimize the effects of CaCl2 and curing duration, producing statistically significant models (p < 0.05, R2 > 0.79). ResultsResults indicated that CaCl2 enhanced early-age strength, GCBA was most effective at moderate OPC levels, and UCS declined when CaCl2 exceeded 2%. The CA75RAP25 mix with 2% OPC and 2% GCBA achieved the highest UCS improvement. DiscussionThese findings highlight the interactive effects of stabilizer contents and curing duration, offering guidance for optimizing CIPR mixtures. ConclusionIncorporating GCBA and CaCl2 can enhance compressive strength, support sustainable reuse of industrial by-products, and improve the performance of pavement rehabilitation projects.
Introduction This study investigates eggshell powder (ESP) as a partial cement replacement in mortar, with an emphasis on its thermal behavior, passive indoor temperature regulation, and synergistic interactions with multiple supplementary cementitious materials - namely fly ash (FA), silica fume (SF), and blast furnace slag (BFS). The effects of ESP on shear strength are also examined, as they remain sparsely documented in existing literature. Distinctively, this research implements a large-scale screening of 60 mix designs (360 specimens) to maximize cement reduction while maintaining or improving mechanical performance relative to the control. Methods Mortars with ESP at 0, 10, 15, and 20 wt.% were tested for flow (EN 1015-3) and for flexural and compressive strengths at 7 and 28 days (EN 196-1). Shear strength at 28 days was measured using the Z-push-off method. Blended (ternary and quaternary) mixes replaced 30 wt.% of cement through combinations of ESP, FA, SF, and BFS. Thermal behavior was monitored using chambers (7 × 15 × 15 cm; wall thickness = 4 cm) made with 0, 15, 30, and 50 wt.% ESP over 30 days, with temperature readings taken at 09:00, 12:00, 15:00, 19:00, and 00:00 via type-K thermocouples. Results are summarized as average values. Results Workability decreased beyond 15 wt.% ESP. The best blended mix (70% cement, 10% ESP, 10% FA, 5% SF, 5% BFS) achieved +12% higher 28-day compressive strength and +17.1% higher 28-day flexural strength compared to the control; the 10 wt.% ESP mix reached +28% higher shear strength at 28 days. ESP-modified mixes exhibited an improved passive thermal response, with peak internal temperature reductions of up to ≈ 7°C during hot periods (≈ 12:00–15:00) and comparable or slightly higher internal temperatures during cooler periods. Discussion Moderate ESP dosages (≈ 5–10 wt.%) can enhance mechanical performance when combined with FA, SF, and BFS, likely through filler densification and nucleation effects in addition to limited pozzolanic activity. Thermal monitoring indicates that ESP contributes to improved passive regulation under variable ambient conditions. However, the practicality of higher ESP levels (> 15 wt.%) decreases due to increased water demand and reduced workability. Conclusion Within SCM-blended systems, ESP provides a cost-effective and eco-efficient approach to cement reduction while maintaining or even enhancing mechanical strength and thermal comfort. However, the findings are limited to laboratory-scale and short-term curing conditions (7–28 days). Therefore, future research should extend to long-term durability assessments - such as freeze–thaw resistance, chloride ion penetration, and sulfate attack - along with microstructural validations (SEM, XRD, TGA), building-scale thermal analyses, and techno-economic evaluations to establish the practical feasibility of ESP-modified mortars for sustainable construction applications.
Introduction Construction of massive monolithic structures requires assessing the risk of early cracking at the stage of concrete hardening. Most finite element method (FEM) programs do not allow taking into account the change in the mechanical properties of concrete over time in thermal stresses calculation for hardening monolithic structures. The purpose of this article is to eliminate this shortcoming. Materials and Methods A new method is proposed that allows the use of standard finite element software in the task of calculating thermal stresses in hardening concrete without any modifications. It was shown that, instead of a structure with a time-varying modulus of elasticity, it is possible to calculate a structure with a constant modulus of elasticity by replacing the actual temperature load with an equivalent one. Results The developed method was tested using the example of the foundation slab. The discrepancy between the calculation results according to our method and the results for a time-varying modulus of elasticity of concrete is insignificant. There is also a satisfactory agreement (discrepancy is less than 5%) with the experimental data up to 6 days, when the risk of early crack formation is highest. Discussion A number of works suggest expressing temperature stresses through the temperature difference between the center and the surface of the structure. It was shown that instead of the actual temperature difference, an equivalent temperature difference should be used. Conclusion The proposed method allows to perform calculations of thermal stresses in hardening concrete using standard FEM software. To obtain true stresses that take into account changes in the elastic modulus over time, it is sufficient to apply an equivalent temperature load to a structure with a constant elastic modulus.
