CivilEng, Volume 4, Issue 2 (June 2023) – 19 articles

Simplicity and optimality are commonly associated with the particle swarm optimization (PSO) algorithm. As a result, numerous variants and hybrids of PSO have been developed and implemented to address structural optimization problems. The undeniable importance of the initialization technique in determining the overall performance of a given optimization algorithm cannot be overstated. Optimization algorithms, such as PSO, typically rely on a random, uniformly distributed initialization. Through multiple iterations and updates, these algorithms aim to achieve optimal results. The underlying assumption behind such an initialization approach is that a fair or reasonable arrangement of particles is best accomplished through randomization, and thus the entire optimization process is iterated based on this assumption. However, this initialization technique raises concerns regarding the attainment of optimality and convergence, leaving room for further examination. In this paper, we challenge this assumption by introducing a priority concept. The key idea is that particles should not be initialized randomly since randomness alone does not guarantee a reasonable allocation of design variable values in iterative optimization. This can lead to misguided velocity updates and ultimately, a time-consuming pursuit of optimality. To address this issue, we formulate priority criteria (PC) and propose an enhanced PSO variant called Priority Criteria PSO (PCPSO). The PC can be incorporated into any PSO variant or hybrid without impacting the parameter settings, constraints, and penalty approaches of the respective algorithms. A case study involving 2D reinforced concrete frames was conducted to compare the performance of the ordinary PSO algorithm with the PCPSO. The results clearly demonstrate that the introduction of the PC leads to a significant cost reduction when compared to PSO with an inertia damping factor. Additionally, the PCPSO algorithm exhibits accelerated convergence. Furthermore, to alleviate the computational burden associated with structural analysis at each iteration, a reanalysis approach called Combined Approximations (CA) is mathematically formulated and implemented. Full article

This work presents a state-of-the-art review of existing fireproof construction guidelines for dwellings against wildfires. The most important wildfire-proof construction guidelines and codes for dwellings are presented, and these are later associated with existing fire engineering chapters associated with building codes. It was concluded that the variability in this subject is very high, and the approach to classifying the thermal effects in construction still lags behind scientific consensus. Moreover, the constructive requirements depend severally on the country’s building code when assessing the fireproof requirements for wildfire. Moreover, the thermal actions of wildfires in dwellings are presented and compared with classical ISO-834 standard fire curves, in which the maximum equivalent fire exposure time can range from 2 to 4 h depending on the country’s code. The key contributions of this work consist of (i) thoroughly disseminating codes and guidelines to promote scientific discussion in order to advance the wildfire fireproof standards dedicated to WUI; (ii) emphasizing the void in current codes in order to promote conversation between future researchers. Full article

Pakistan is currently facing physical and economic water scarcity issues, which have been further complicated by the rapid increase in its population and climate change. In affected areas, many methods are being used to tackle this problem, among which rainwater harvesting (RWH) provides the best alternative source of domestic water supply. In rainwater harvesting, a mechanism is designed to effectively collect surface runoff during rainfall events from residential rooftops. It has also been found that rainwater has great potential as a source of water supply in residential areas of major cities, such as Lahore, which is the focus of our study. This research paper examines rainwater harvesting as a sustainable solution to address the challenges of drinking water scarcity and urban flooding. The study discusses the benefits of rainwater harvesting, including reducing reliance on municipal water sources, improving water quality, and mitigating the impact of urban flooding. Additionally, the paper explores the use of filtered water points in conjunction with rainwater harvesting systems to provide clean drinking water to communities. The research draws on case studies from various regions to illustrate the effectiveness of rainwater harvesting as a sustainable solution to water scarcity and urban flooding. Ultimately, the study concludes that rainwater harvesting, when coupled with filtered water points, can offer an effective and sustainable solution to address drinking water scarcity and urban flooding. Full article

Structural pounding between adjoining multistory buildings with different total heights and different story levels has been repeatedly identified as a frequent cause of severe damage during seismic excitations. This phenomenon is very intense when upper floor slabs of short buildings hit the columns of taller and more flexible structures within their deformable length. On the other hand, it is well accepted that infill masonry panels strongly affect the seismic response and overall behavior of multistory reinforced concrete (RC) frames and especially in the common case of an open first story (pilotis). Thereupon, the interaction between a multistory frame with an open first floor and shorter and stiffer adjacent buildings was studied and the influence of the open first story on pounding investigated with inelastic dynamic step-by-step analyses. The results of the pounding cases of an 8-story RC frame with a single story and 4-story buildings were examined. Three cases of short structures were considered as follows: a frame structure, a stiff structure and a very stiff non-self-vibrating one. All studied interaction cases included type A (floor-to-floor) pounding cases and type B (floor-to-column) pounding cases. This study focused on the influence of an open first story (pilotis) on the pounding phenomenon. Therefore, all examined two-building poundings were studied considering two cases: the first case involving a fully infilled 8-story frame and second case involving an infilled 8-story structure with an open first story (pilotis). Moreover, as expected due to the asymmetry of the examined two-structured pounding pairs, the directions (plus and minus) of the seismic excitation proved to be important for the evaluation of the developing capacity demands. In the present study for the first time, it is stressed that pounding cases between structures with different geometries (asymmetric) have to be examined in both directions (plus and minus) of each seismic excitation. From the results, it can be deduced that the developing shear forces on the columns that suffer a hit in the case of type B pounding exceed the shear strength of the column even if detailing for critical regions according to Eurocode 8 is applied. Further, it is inferred that pilotis configuration increases the developing pounding forces and consequently increases the capacity demands mainly in terms of the ductility of the column that suffers the hit. Full article

Magneto-rheological dampers (MR-Dampers) are increasingly being used in construction applications to reduce the dynamic response of structures to seismic activities or severe wind loading. Sensors attached to the structure will signal the computer to supply the dampers with an electric charge that transfers the MR fluid to a near-solid material with different physical and mechanical properties (viscoelastic behavior). Control algorithms govern the fluid to near-solid conversion, which controls the behavior of the damper and the performance of the structure under the seismic or wind loading event. The successful optimization of control parameters minimizes the overall structural response to dynamic forces. The main objective of this research is to change the output behavior of specific floors within a building subjected to seismic excitation by optimizing the MR-Damper control parameters to impact the behavior of a specific floor or number of floors within the building. The adjustment of control parameters to attain this objective was validated in multiple case studies throughout this research. The successful implementation of the research outcome will result in optimized MR-damper design to meet the performance-based criteria of building projects. Full article

This paper presents a numerical study on the thermal effect of the insulation of lightweight concrete in hybrid GFRP-concrete structures. In these hybrid structures, the GFRP profiles are totally covered by normal and lightweight concrete and subjected to thermal loads. The problem with GFRP structures is their weak thermal resistance, even at moderately high temperatures. To promote some thermal insulation, it is recommended to cover the GFRP profile with concrete, but this increases its weight. Therefore, lightweight concrete may be a good solution due to its insulation capabilities. For this study, the thermal loads used in the numerical campaign are based on a nominal fire-curved ISO-834, and the temperature is measured at several points. Using these temperatures, it is possible to conclude that the effect of lightweight concrete may provide structural benefits when compared with classical standard structural concrete for covering GFRP profiles using different cover values (from 5.0 cm to 2.5 cm). For this work, commercial finite element software was used for the thermal nonlinear analysis. It was possible to conclude that with lightweight concrete, it is likely to have half of the cover and still maintain the same level of insulation as regular concrete. Full article

To address the rapidly growing demands of traffic congestion, more highway bridges have been constructed, especially curved bridges. With more curved bridges designed and constructed, people have conducted a comprehensive analysis of the structural performance. Due to the nature of the structural complexity of curved bridges, dynamic responses of the curve bridges vary dramatically from the standard linear bridges. Although some work has been conducted to investigate the curved bridge dynamic analysis under seismic inputs, the framework for analyzing the curved bridges’ vulnerability under various angles of inputs is still lacking. In this paper, we conducted a series of curved bridge seismic analyses based on different inputs and conducted a parametric study of the bridge performance using finite element models. We conducted time history analyses by applying seismic inputs to investigate the bridge dynamic responses based on different angle inputs and other different structural parameters. We developed an approach identifying the most vulnerable direction of the seismic inputs and the strongest dynamic responses for curved bridges based on time series analysis. This approach was validated with the dynamic analysis of a simplified bridge model. The method developed in this paper will help improve the curved bridge design code and further provide suggestions about mitigating seismic response for device design. Full article

Existing literature suggests that substituting mineral aggregates with tire-derived aggregate (TDA) in concrete increases the ductility and toughness of the concrete at the cost of lowering its strength and stiffness. Hence, TDA concrete has applications in dynamic systems, such as lateral resisting frames sustaining seismic loads. This study investigated the application of TDA concrete in buckling-restrained braced frames (BRBFs). Buckling-restrained brace (BRB) specimens included steel plates encased with concrete mixtures containing TDA coarse aggregates compared to conventional concrete. Testing involved shake-table testing of a single-span, one-story, steel-braced frame with single-leg conventional or TDA concrete BRBs under harmonic, periodic, impulse, and ground motion loadings. Results included time-history responses and backbone curves of the BRBF specimens. Analytical interpretation of results included determining effective mass, stiffness, damping ratio, toughness, and ductility of BRBFs for TDA versus conventional concrete. Full article

While megaprojects can be defined as highly complex, time-consuming, and cost-intensive endeavors, for rail infrastructures they are even more problematic. As a starting point, for rail megaprojects, their scope may, at times, alter due to some risks and uncertainties. As many such projects exceed many years in development, their scope and formation will not be a linear trajectory. It is, therefore, the aim of this paper to evaluate the difficulties in determining the scope of rail megaprojects. This paper first introduces the theoretical framework via adaptive decision-making and policy setting when dealing with mega rail projects. Through sustainable development, carefully applied research is undertaken to highlight some of the key shortfalls of current practices when dealing with mega rail projects. This includes categorizing sustainability into four dimensions: social, economic, environmental, and engineering for rail infrastructure. To address the existing gap in the literature, including the appropriate alignment of policy planning and design, this paper will carefully review the complex science of rail megaprojects. This can be seen as a conceptual framework, which combines complex theory and practice to develop a theoretical perspective to initiate, plan, execute, and commission mega rail projects. Particularly with an international focus, this paper will review global development, targeting rail infrastructures. For rail megaprojects, strategically integrated objectives are traditionally key functions within the regional land transport network along with the national network and are necessary to (i) improve connectivity, both nationally and inter-regionally for people, communities, regions, and industry via effectively linking the existing broad-based transport network; (ii) enhance logistical systems and trade; (iii) provide a consistent framework for continuous sustainable development; and (iv) provide a consistent framework for long-term economic and social benefits. Full article

Unlike steel reinforcements in concrete, Fiber Reinforced Polymer (FRP) materials are light and free from corrosion. Therefore, FRP materials are increasingly being used in structural engineering as a replacement for steel reinforcements. While the use of FRP bars as longitudinal reinforcements in concrete deep beams has been studied somewhat widely, their use and effectiveness as web reinforcements are not well studied. In this study, the effect of the FRP web reinforcements on the behaviour and strength of FRP-reinforced concrete deep beams were investigated in an experimental study. Four glass fiber-reinforced concrete (RC) simply supported deep beam specimens were tested under a concentrated load with different shear span-to-depth ratios and web reinforcement ratios. The behaviour of the deep beams was described in terms of load–deflection behaviour, crack developments, strain in FRP reinforcements, and failure modes. The experimental investigation emphasized the significance of web reinforcements in determining the reinforced concrete deep beam behaviour, such as mid-span deflection, crack breadth, failure modes, and ultimate strengths. Furthermore, to predict the behavior of deep beams, numerical Finite Element models using Abaqus software were created. The present test results were compared to those predicted using the Finite Element models. This investigation shows that web reinforcement is quite important for FRP-RC deep beams to achieve a robust behaviour by enhancing its capacity and deformability. Full article

Damage assessment of corroded steel members due to severe exposure conditions, has been a vital component for determining the strengthening requirements of existing deteriorated structures, to overcome possible devastating failures. This article mainly focuses on steel angle members, which are mostly used as axially loaded members in different types of applications. In this study, the strategy of thickness reduction at corroded locations was demonstrated as a simple, convenient, and accurate method to represent the corrosion-equivalent properties of steel angles under axial compression. Further, the viability of the thickness reduction approach was evaluated in code-based and numerical approaches. Four standards, BS 5950-1:2000, BS EN 1993-1-1:2005, ASCE 10-15 and ANSI/AISC 360-16 were investigated to identify their applicability to obtain the residual compression capacities of corroded members. The capacity estimations of codes were compared with experimental data to demonstrate that the estimations of codes are not accurate when the level of corrosion is high. Finally, 39 corroded steel angle members of 10 different corrosion patterns were numerically modeled and analyzed to demonstrate the impact of different corrosion patterns on the compression capacity. Full article

Strengthening of composite beams is highly needed to upgrade the capacities of existing beams. The strengthening methods can be classified as active or passive techniques. Therefore, the main purpose of this study is to provide detailed FE simulations for strengthened and unstrengthened steel–concrete composite beams at the sagging and hogging moment regions with and without profiled steel sheeting. The developed models were verified against experimental results from the literature. The verified models were used to present comparisons between the effect of using external post-tensioning and CFRP laminates as strengthening techniques. Applying external post-tensioning at the sagging moment regions is more effective because of the exhibited larger eccentricity. In the form of an initial camber and compressive stresses in the bottom flange prior to loading, this reasonable eccentricity induces reverse loading on the reinforced beams, reducing the net tensile stress induced during loading. Using CFRP laminates on the concrete slab for continuous composite beams is more effective in enhancing the beam capacity in comparison with using the external post-tension. However, reductions in the beam ductility were obtained. Full article

This review aims to investigate the recent advancements in the performance of earthquake-damaged reinforced concrete structures subjected to fire loading and the damages that are induced by fire to reinforced concrete structural elements with damage due to seismic loads. The first part of the paper provides a general understanding of the Post-Earthquake Fire (PEF) effect on reinforced concrete structures, and some statistics regarding the previous earthquake casualties and amounts of destruction in different regions of the world are addressed. In the second part of the investigation, an in-depth review of the experimental and numerical procedures of PEF analysis in concrete columns, beams, slabs, and full-scale RC frames and the types of damages in RC members due to PEF have been presented, giving a general review of the results and conclusions in previous research in PEF in different reinforced concrete structures. In the end is discussed the concept of hybrid fire simulation, its applications in engineering problems, the methodologies that consider full interaction effects as well as recent breakthroughs in studying PEF using Real-Time Hybrid Simulation. Full article

The aim of this work is to determine how the mechanical and physical properties of render mortars, in particular their moisture performance, are affected by the application of paint. In this study, three commercial paints, hydro-pliolite-based paint, acrylic paint and silicate paint, were applied as coating layers on render mortars formulated with different binders. The choice of the binders used (hydrated lime, natural hydraulic lime and cement) was related to the functional requirements that the renders have to fulfil according to the type of buildings where they are applied (i.e., new or old buildings). Firstly, the hardness and surface cohesion of the different painted and unpainted renders were analysed in order to investigate the effect of the type of paint on the mechanical strength of the render surface. The influence of the paints on the moisture behaviour of the renders was then investigated using the water capillarity test, the water vapour permeability test and the drying test. The results show that all the paints studied can cause a significant change in the behaviour of the renders in terms of moisture transport phenomena. Nevertheless, it can be concluded that acrylic paint has the greatest resistance to water absorption, but it is also the paint with the higher resistance to water vapour diffusion. Hydro pliolite paint was found to be adequate from the point of view of reducing moisture accumulation and is the most recommended for old buildings with hydrated lime or hydraulic lime-based renders. Full article

Portland cement (PC) is a common material used in civil infrastructure engineering. Cement production emits roughly 2.2 billion tons of CO₂ per year, contributing 8% of global emissions in 2016. This contributes to almost half of the calcination process, and together with thermal combustion, clinker generation could be responsible for 90% of the sector’s emissions. One effective technique for dealing with these industrial by-product wastes is to employ them to make cement replacements such as concrete and mortar, which can be used in a variety of applications. As a result, the purpose of this research is to review the current advancements, challenges, and future perspectives on the utilization of agro-industrial waste (AIW) produced around the world in cement-based products. Geopolymers (GPs), on the other hand, reduce carbon dioxide emissions and have the potential to be a complete or partial replacement for PC in the construction sector. The GP technology enables the use of AIW in combination with an alumina–silicate (A–S) phase with minimal environmental impact. GP-cement is mostly produced by activating alkali silicates or alkali sols with secondary raw materials such as calcined clays, fly ash (FA), zeolite, metakaolin, etc. Mixing various resource materials, including additives, A–S, and alkali sols, alkali concentrations, optimizing the curing temperature, the SiO₂/Na₂O ratio, microstructural behavior, and other factors, results in GP-cement with outstanding mechanical and durability characteristics. The review concludes that AIW-based geopolymer composites have shown promising results in terms of their mechanical properties, durability, and environmental sustainability, which makes them emerge as promising future building materials with applications in a wide range of industries. Full article

Transportation agencies periodically conduct signal retiming (i.e., optimization) to ensure efficient signal operations. Previous studies introduced the notion of the “resonant cycle length” (RCL), which is based on the premise that a good progression of traffic on the corridor mainline for various volume fluctuations can be achieved with an appropriate value of cycle lengths, where all other signal timing parameters (splits, offsets and phase sequences) remain unaltered. Several follow-up studies brought many inconsistencies in the previously introduced concept. For instance, authors would investigate the existence of the RCL by evaluating the performance of signal timing plans for not only coordinated movements (side streets and coordinated movements together), but would optimize all signal timing parameters (not only cycle lengths) while investigating. This study sheds light on the RCL concept and highlights the importance of all signal timing parameters for signal performance. In addition, we introduce a concept called the resonant signal timing plan (RSTP) as a refinement for the RCL, which represents a combination of signal timing parameters that (unaltered) retain an acceptable performance for a variety of traffic conditions. Results show that different sets of signal timing parameters cause plans to be resonant depending on the evaluation type. Full article

Most transmission pipelines are buried underground per regulations, and external corrosion is the leading cause of failures of buried pipelines. For assessing aged pipeline integrity, many corrosion assessment models have been developed over the past decades. This paper delivers a technical review of corrosion assessment models for determining the remaining strength of thin- and thick-walled pipelines containing corrosion defects. A review of burst prediction models for defect-free pipes is given first, including the strength- and flow-theory-based solutions, and then of those for corroded pipes. In terms of the reference stress, the corrosion models are categorized into four generations. The first three generations correspond to the flow stress, ultimate tensile stress (UTS), and a combined function of UTS and strain-hardening rate, while the fourth generation considers the wall-thickness effect. This review focuses on recent advances in corrosion assessment methods, including analytical models and machine learning models for thick-walled pipelines. Experimental data are used to evaluate these burst pressure prediction models for defect-free and corroded pipes for a wide range of pipeline steels from low to high grades (i.e., Grade B to X120). On this basis, the best corrosion models are recommended, and major technical challenges and gaps for further study are discussed. Full article

The transition to a design based on information modeling has paved the way for automated verification of project documentation. The most complicated type of design documentation check is the assessment of compliance with the requirements of regulatory documents since its automation requires the translation of statements written in natural language into a machine-readable format. At the same time, building codes and regulations should be suitable for translation into machine-readable form. However, a large number of provisions presented in regulatory documents cannot be subjected to automated verification due to their specific features. This study aimed to analyze the suitability of the regulatory provisions to be translated into a machine-readable format, identify limiting factors, and establish recommendations to avoid these factors. This study was conducted based on the example of the code of rules for “Residential Apartment Buildings” (SP 54.13330.2016) applied in the Russian Federation. During the research, a previously developed algorithm that generates rules for checking building information models and is based on the RuleML language was applied to the provisions of the standard above to identify statements that can and cannot be translated. As a result, 356 statements were received, which were divided into five groups: requirements suitable for translation into a machine-readable format, requirements containing links to other documents (regulatory and not only), requirements of uncertain interpretation, requirements that cannot be verified based on an information model, and informative requirements. For the first group of statements, there were examples given for both the statements and the rules derived from them. For the other four groups, examples of statements were supplied with factors preventing the translation of requirements into a machine-readable format and solutions on how to avoid these factors. An analysis of the distribution of statements (related to the above-mentioned groups) by sections of the standard showed that a significant part of the requirements is suitable for translation into a machine-readable format. The possible obstacles to translation can be overcome by attracting experts and using programming tools. The paper also makes recommendations on how to arrange new standard structures. Full article

Reusing waste is one of the most recent topics and one of the main contributors to sustainability. It is known that concrete is one of the most common materials to produce different types of construction members around the world. That is due to mainly its low cost, availability, long period of durability, and ability to withstand harsh environments. On the other hand, due to the rapid changes that have happened in the last few decades in the production of decorative materials, some material types of cladding are used for decoration purposes, such as Styrofoam (EPS) (trade name “Astropol”), which is developed from disposal materials. Discovering and implementing a method of reusing these wastes in concrete is beneficial for the environment to reduce waste around the globe. In the current study, Styrofoam (Astropol) waste was used as a replacement for fine aggregate since concrete structures contain this material in their composition. It is important to test these materials for fire resistance and expose them to an elevated temperature in order to discover the post-fire mechanical properties of the composite material. The experimental result showed that the post-fire compressive strength of concrete containing different ratios of EPS (Astropol) increases compared to conventional concrete. The compressive strengths were 19.94 MPa, 19.295 MPa, 16.806 MPa, and 17.66 MPa for 0%, 15%, 25%, and 50%, respectively, while the post-fire indirect tensile strength for all specimens containing EPS reduced as the fire duration and temperature increased. Full article