Construction Technologies and Architecture Vol. 21

Abstract: Sugarcane bagasse ash (SCBA) is a by-product of the ethanol and sugar industry. SCBA is generally used as fertilizer or dumped in landfill, which has led to increasing environmental problems. In the recent years, SCBA has been investigated in the field of construction materials due to its pozzolanic character. This research aims at examining some physical and mechanical properties of mortars with partial replacement of sugarcane bagasse ash from sugar cane refineries. In the present case, the cement substitution was made with SCBA at 0%, 15%, and 30% of the binder (Cement + ash). The physical and mechanical testing of the mortar was carried out to determine the effect of ash addition on porosity, density, flexural and compressive strengths of the mortar. In general, the findings revealed that the mechanical and physical behavior of the mortar mixtures improved over time because of pozzolanic effects. On one hand, the physical changes were relatively restricted and do not show a well-established trend. On the other hand, reduction of mechanical strength was observed with the addition of SCBA, and with a 15% cement replacement percentage, it is possible to obtain a material with favorable physical and mechanical properties.

Abstract: The incorporation of rubber aggregates in SCC significantly affects fluidity, viscosity, and passing ability. In the research presented here, a hybrid multi-criteria decision-making method is adopted with a combination of the CRITIC method and Taguchi-TOPSIS optimization in order to evaluate the rheological properties of RSCC. The eighteen SCC mixes with varying percentages of rubber, ranging from 5% to 30%, are evaluated in terms of slump flow, V-funnel flow time, L-box passing ability, viscosity, and yield stress. The results show that when the proportion of a single type of rubber granule exceeds 20%, the rheological properties of the blend, such as flowability and passability, are significantly degraded. This contrasts with the combination of several types of rubber (20% fine rubber and 25% coarse rubber). This suggests that a homogeneous mixture can help reduce the adverse effects associated with high individual rubber contents,with enhanced sustainability and retention in self-compaction. The optimization analysis of 18 RSCC formulations indicated that RSCC5/G achieved the highest proximity score (C=1.0), while mixes having rubber content exceeding 20% had proximity scores less than 0.8, pointing to significant rheological decline.

Abstract: The increasing demand for sustainable construction materials is driving significant research into Self-Compacting Earth Concrete (SCEC), an innovative solution that combines the ecological advantages of earth construction with the efficiency of concrete casting. This bibliometric analysis maps the current research landscape of SCEC, highlighting publication trends, key contributors, influential journals, and prevalent themes in the field. Utilizing data from prominent academic databases, the study reveals a steady growth in interest and output over the last two decades. Key challenges such as material deflocculation, setting time control, and earth type selection are addressed through optimization and rheological investigations, demonstrating SCEC's superior thermal performance and humidity regulation while reducing carbon emissions. This research underscores the importance of SCEC in promoting sustainable construction practices and identifies future research directions essential for advancing the field, serving as a valuable resource for researchers, practitioners, and policymakers.

Abstract: Like many other nations, Morocco is grappling with escalating water stress, exacerbated by climate change, decreasing rainfall, and the increasing demand for water, particularly within the civil engineering sector. The growing reliance on concrete, driven by infrastructure development, has intensified pressure on already limited freshwater resources, presenting a significant challenge. In this context, the use of seawater in concrete mixing emerges as a promising alternative. While many studies explore ways to reduce freshwater consumption in civil engineering, few specifically address the use of seawater in concrete production. Seawater, which contains high levels of chloride and sulfate ions, can lead to the corrosion of steel reinforcements and potentially compromise the long-term durability of structures. Our research aims to explore this solution through a multi-phase approach. Initially, we will establish criteria for the acceptability of seawater as mixing water. Subsequently, we will conduct laboratory tests to assess the strength and durability of concrete made with seawater, comparing it with that produced using freshwater. Based on these findings, we will propose technical improvements to minimize the corrosive effects and enhance the viability of this approach. Ultimately, this study seeks to contribute to sustainable water management in the construction industry by alleviating pressure on freshwater resources, while supporting the growth and development of Morocco’s infrastructure.

Abstract: The dynamic nonlinear behavior of a beam, which is modeled as mass-spring mechanical systems, is the main subject of this investigation. Unlike most previous research that considers homogeneous and uniform beams, the findings of this research hold significant developments for the nonlinear vibration of non-homogeneous beams, which can be described as a bar-helical spring system. In this system, the mass of each bar changes over the length of the beam according to the local mass density of the non-homogeneous beam. The five-degree-of-freedom mass-spring model used in this paper can also be expanded to multi-degrees-of-freedom or even to a continuous system. The nonlinear beam response is investigated for three situations of increasing mass density and contrasted with its influence on dynamic features such as amplitudes, mode shapes, and natural frequencies. Therefore, three cases of mass distribution are considered for both symmetric and asymmetric nonlinear stiffness. Results are given as plots of vibration amplitude versus non-dimensional natural frequency for various cases of mass distribution. Obtained results underscore how mass density and stiffness symmetry critically influence the nonlinear beam dynamic response.

Abstract: Enhancing the energy efficiency of administrative buildings is a critical factor in advancing global energy sustainability. This research introduces a methodology for refining thermal loads and minimizing energy consumption through computational simulations using the HAP (Hourly Analysis Program) tool. The primary goal is to transform an energy-demanding administrative structure into an environmentally sustainable and high-performance facility. A comprehensive assessment of the building’s initial state uncovered structural inefficiencies influencing its energy demand, particularly regarding insulation, air circulation, and lighting. By incorporating advanced architectural and engineering solutions, including upgraded insulation, LED lighting implementation, and optimized HVAC system configurations, the findings indicate a considerable reduction in energy usage. This study emphasizes the necessity of integrating ASHRAE regulations and computational simulation methodologies in advancing building energy performance.

Abstract: Concrete, often conceptualized as an inert construction material, is fundamentally a dynamic composite that undergoes continuous physicochemical transformations throughout its service life, governed by natural degradation processes and mechanical aging. Despite its widespread utility, concrete’s quasi-brittle behavior, characterized by low tensile strength and susceptibility to abrupt failure under traction-dominated loading regimes, remains a critical limitation in structural engineering. To address these intrinsic vulnerabilities, the rehabilitation of concrete infrastructure has emerged as a pivotal research domain, with advanced retrofitting techniques focusing on enhancing tensile performance and transitioning failure modes from brittle to ductile. Among these, externally bonded reinforcement (EBR) using fiber-reinforced polymer (FRP) composites has gained prominence as a high-efficacy solution for augmenting load-bearing capacity and structural resilience. This study employs a parametric finite element analysis (FEA) framework in Abaqus/CAE to systematically evaluate the mechanical efficacy of two distinct carbon fiber-reinforced polymer (CFRP) retrofitting strategies: (1) externally bonded CFRP plates and (2) internally embedded CFRP reinforcement within the beam’s cross-section. The computational investigation quantifies the influence of reinforcement placement on critical performance metrics, including ultimate load capacity, deformation ductility, and failure mechanisms. Numerical results demonstrate that internally integrated CFRP reinforcement significantly enhances structural ductility and peak load resistance, while maintaining a marginal mass differential. These findings underscore the critical role of reinforcement topology in optimizing stress redistribution and crack mitigation, offering actionable insights for the design of next-generation retrofitting protocols that prioritize both strength and serviceability. The study advances the discourse on sustainable infrastructure rehabilitation by delineating a pathway for leveraging embedded composite systems to transcend the inherent limitations of conventional concrete matrices.

Abstract: This work presents a theoretical and numerical study on the nonlinear free vibrations of orthotropic laminated composite beams, with a focus on different material orientations such as cross-ply, balanced, and woven configurations. Based on the Euler-Bernoulli beam theory and Von Karman’s geometric nonlinearity, we develop an analytical and matrix formulation using Hamilton’s principle. The novelty lies in the use of a homogenization approach to derive equivalent stiffness properties, allowing the comparison between symmetrical and asymmetrical composite beams. Despite limitations inherent to Euler-Bernoulli assumptions, results show the significant influence of layer orientation on the nonlinear frequency and displacement behavior. This study is valuable for structural applications in aerospace and mechanical systems.

Abstract: Modal truncation errors in structural dynamic analysis arise when only a limited number of modes are retained in the modal basis, leading to significant inaccuracies in eigenfrequency predictions and mode shape estimations. This study presents a novel modal reanalysis technique that incorporates residual flexibility terms to account for the contribution of neglected higher-order modes, thereby reducing truncation errors without increasing the system's degrees of freedom in structural dynamic modification problems. The study presents an efficient modal reanalysis technique that is less expensive and more accurate, which can be used to evaluate the natural frequencies and mode shapes of a modified structure. The uniqueness of this technique lies in the structure of the formula, which emphasizes the contribution of unknown modes. This contribution can either be calculated for a finite element model or identified through an experimental model test. Numerical tests are provided to demonstrate the effectiveness of this method. High-quality results can still be obtained even if the modifications made to the structure are significant.