CivilEng

Given the apparent gap between scientific research and engineering practice, this paper tracks the dominating perspectives that have shaped the growth of hydrological research. Based on five eras, dominated with specific paradigms and/or ideologies, this paper highlights the punctuated growth of flood frequency analysis comparative to the enormous progress made in hydrological modeling can be claimed by the 20th century. The historical narrative underpinning this inquiry indicates that progress in hydrological understanding can be characterized by two contrasting claims: modeling breakthroughs and inconclusive results. Contradicting statistical assumptions, complex modeling structures, the standardization of specific techniques, and the absence of any unified physical meaning of the research results brought an apparent conflict between the scope of hydrologic research and the scope of end users, i.e., civil engineers. Some hydrologists argue that the debates associated with hydrologic progress, i.e., the evolution of statistical methods, dating back to the 1960s remain unaddressed, with each era introducing additional uncertainty, questions, and concerns. Progress, for it to happen, needs synthesis among scientists, engineers, and stakeholders. This paper concludes that, in a similar way to how physicists acknowledge the conflicts between quantum and Newtonian physics, hydrology too can benefit from acknowledging divergent principles emerging from engineering practice. While many advanced analytical tools—though varied in form—are grounded in the assumption that past data can predict future conditions, the contrasting view that past data cannot always do so represents a key philosophical foundation for resilience-based civil engineering design. Acknowledging contrasting philosophies describing the nature of reality can help illuminate the conundrum in the scope of hydrological research and can enable synthesis activities aimed at ‘putting the puzzle together’. Full article

The increasing integration of Chinese-engineered infrastructure in Pakistan under the China–Pakistan Economic Corridor (CPEC) necessitates a comparative evaluation of seismic resilience between the Chinese and Pakistani building codes. This study focused on the seismic performance of reinforced concrete (RC) frames designed according to these two codes. Fragility curves were generated for 4-story, 8-story, and 12-story buildings subjected to varying seismic intensities using Incremental Dynamic Analysis (IDA). The results indicate that structures designed under the Chinese code exhibit up to 12% lower fragility values, suggesting enhanced seismic resilience, particularly at higher seismic intensities. Additionally, the study investigates the effectiveness of Lead Rubber Bearings (LRBs) for seismic isolation, demonstrating that their integration improves the seismic performance of RC frames by enhancing energy dissipation and reducing the likelihood of exceeding various damage states by up to 25%. These findings underscore the importance of adopting stringent seismic design provisions, such as those found in the Chinese code, to enhance the resilience and safety of infrastructure, especially in seismic-prone regions. Full article

The structural performance of mid-rise buildings with a soft first story is a critical issue in earthquake-prone regions. This paper presents a detailed assessment of both the seismic performance and the structural reliability of a confined masonry mid-rise building with a soft reinforced-concrete first-story irregularity located in Mexico. This structure was designed according to outdated building codes to reflect construction practices that remain common in some parts of the country. Nonlinear dynamic analyses were conducted using ETABS v21. To simulate various seismic scenarios, ground motion records associated with return periods of 72, 475, and 975 years, respectively, were implemented. The results demonstrated that maximum inter-story drift is predominantly concentrated at the first story, exceeding the performance thresholds for immediate occupancy, life safety, and collapse prevention. Furthermore, a probabilistic performance assessment was developed considering the randomness of inter-story drift responses. Then, reliability index (β) was calculated for each seismic scenario. In all cases, β values remained consistently below the minimum recommended limit. These findings confirm the formation of a soft-story mechanism at the first level and are relevant for buildings designed under construction provisions like those used in the present case study. Full article

This study presents an environmentally friendly alternative to conventional energy-intensive methods for soil improvement by investigating an enzyme-induced active magnesium oxide carbonation (EIMC) technique for the stabilization of gravelly soil. The solidification efficacy and strengthening mechanism of EIMC-treated soil were systematically investigated through a combination of mechanical property tests and microstructural analyses. Results indicate that key mechanical properties—including compressive strength, shear strength, and elastic modulus—were directly proportional to the magnesium oxide (MgO) content. Notably, an 8% MgO content resulted in a 113-fold increase in unconfined compressive strength (UCS) compared to the untreated soil. The strength development stabilized after a five-day curing period. While higher MgO content yielded greater absolute strength, the efficiency of strength gain per unit of MgO peaked at a 4% dosage. Consequently, considering both performance and efficiency, an MgO content of 4% and a curing period of 5 days are recommended as the optimal parameters. The EIMC treatment substantially improved the soil’s mechanical properties, inducing a transition in the failure mode from plastic to brittle, with this brittleness becoming more pronounced at higher MgO concentrations. Furthermore, the treatment enhanced the soil’s water stability. Microstructural analysis revealed that the formation of hydrated magnesium carbonates filled voids, cemented particles, and created a dense structural matrix. This densification of the internal structure underpinned the observed mechanical improvements. These findings validate EIMC as a feasible and effective eco-friendly technique for gravelly soil stabilization. Full article

It is undeniable that digital technology enables, e.g., building information modelling, digital twins, extended reality (i.e., virtual reality, augmented reality, mixed reality), and automation, have recently played a significant role in the construction and engineering industry. The traditional applications of digital technologies include design and construction management, waste management, and, to a limited extent, asset management. Despite some applications of digital technologies, the technology users are often isolated and siloed. In reality, the cross-functional applications, roles, and co-benefits have not been thoroughly understood or well demonstrated. This is evident by a very limited usage of such technology across either the whole lifecycle or the value chain of built environment sectors. On this ground, this study is the first to tackle the challenges by conducting expert and stakeholder interviews using open-ended questionnaires both online and offline (n = 42) to identify synergic roles and influences, as well as co-benefits of digital technology enablers. Industry participants are dominant in our study and, unsurprisingly, siloed practice can undermine cross-collaboration among value chain stakeholders. Clearly, co-benefits may hypothetically occur, but they can be only unlocked by genuine, participative stakeholder engagement. This study is unprecedented, and our new findings also reveal technical and societal capabilities of digital technologies, which can inclusively enable participative decision-making, engagement, and integration of stakeholders for implementing buildings’ circularity through viable business and management models. New insights clearly exhibit that digital technology enablers must be co-created by main stakeholders in order to yield co-benefits and harvest synergic value for circular management models in the built environment. Full article

This paper analyzes the physics of the TMD-Inerter for harmonic vibrations. The basic TMD-Inerter layout is assumed, where the inerter is installed between the TMD mass and the structural mass. For harmonic vibrations, the inerter force can be formulated as a function of terminal displacements. This formulation demonstrates that the inerter force is, in fact, a negative stiffness force with frequency-dependent negative stiffness coefficient. Based on this finding, the optimal stiffness tuning of the TMD-Inerter is derived. As this stiffness tuning can only be realized by a controlled actuator, the tuning of the spring of the TMD-Inerter is presented. As this spring is a passive element, its optimum tuning must be made at a selected frequency of vibration. It is shown that the average of the TMD natural frequency and structural eigenfrequency leads to a close to optimal spring tuning. This approach needs to be combined with increased damping of the TMD-Inerter to minimize the structural displacement response. Despite the close to optimal tunings of stiffness and damping, the resulting primary structure displacement response is approximately 41.6% greater than that due to the classical TMD. The reason for this lies in the fact that the passive spring of the TMD-Inerter cannot compensate for the frequency-dependent negative stiffness of the inerter within the entire frequency range. Full article

Within the scope of this article is the presentation of a modelling and measurement approach for the effects of roof greenings and the application of the approach to evaluate the influence of roof greenings upon the thermal conditions inside a typical residential building. It is shown that overheating in summer can be reduced, and thermal comfort for inhabitants can be increased. The cooling is caused by the transpiration of plants and by the evaporation of water from the substrate. Other relevant physical effects are the shading of plants and the increase in the heat capacity of the building. In state-of-the-art buildings, a layer with a high insulating effect is incorporated into the envelope. This leads to the effect that a huge fraction of the cooling power is taken from the outside of the building and only a smaller part is taken from the inside. In order to mitigate this decoupling, a hydraulic connection between the greening and the interior of the building is introduced. To evaluate the effect of the inside cooling, the difference in the number of yearly hours with overheating in residential buildings is estimated. In addition, the reduction in energy demand for the climatisation of a typical residential building is calculated. The used methods are as follows: (1) Performance of laboratory and free field measurements. (2) Simulation of a typical residential building, using a validated approach. In summary, it can be said that green roofs, in particular with hydraulic connections, can significantly increase the interior thermal comfort and potentially reduce the energy required for air conditioning. Full article

Traditional construction logistics rely on manual processes and fragmented tools, leading to inefficient planning, poor communication, and disorganized supply chains. Despite advances in digitalization, there is a lack of integrated, data-driven approaches tailored to construction logistics. To address this gap, this paper adopts a design-science approach to develop and evaluate a modular Digital Twin (DT) framework, the ConLogTwin. The framework integrates planning data with real-time site data through a robust data storage layer and digital services for automated planning and analytics. A prototype demonstrates the technical feasibility of mirroring both physical and organizational setups of projects, enabling more efficient and adaptive logistics management. The work contributes a modular reference architecture that integrates established open-source tools into a coherent, adaptable framework for construction logistics, enhancing practical applicability and lowering implementation barriers. A limitation is that the framework has not yet been validated in a full-scale field study, leaving its effectiveness in practice to be tested in a future study. Full article

The incorporation of Basalt Fiber-Reinforced Polymer (BFRP) materials marks a significant advancement in the adoption of sustainable and high-performance technologies in structural engineering. This study investigates the flexural behavior of four-meter, two-span continuous reinforced concrete (RC) beams of low and medium compressive strengths (20 MPa and 32 MPa) strengthened or rehabilitated using near-surface mounted (NSM) BFRP ropes. Six RC beam specimens were tested, of which two were strengthened before loading and two were rehabilitated after being preloaded to 70% of their ultimate capacity. The experimental program was complemented by Finite Element Modeling (FEM) and analytical evaluations per ACI 440.2R-08 guidelines. The results demonstrated that NSM-BFRP rope application led to a flexural strength increase ranging from 18% to 44% ductility by approximately 9–11% in strengthened beams and 13–20% in rehabilitated beams, relative to the control specimens. Load-deflection responses showed close alignment between experimental and FEM results, with prediction errors ranging from 0.125% to 7.3%. This study uniquely contributes to the literature by evaluating both strengthening and post-damage rehabilitation of continuous RC beams using NSM-BFRP ropes, a novel and eco-efficient retrofitting technique with proven performance in enhancing structural capacity and serviceability. Full article

UHPC has been found to have excellent freeze–thaw durability in cold regions. Previous UHPC testing performed has mostly focused on concrete with compressive strength above 21 ksi (145 MPa). In this study, testing was conducted to determine at what strength level concrete transitions to provide excellent freeze–thaw (F–T) performance. Non-proprietary concrete samples were made for freeze–thaw durability from four different concrete mixture designs: 12–15 ksi, 15–18 ksi, 18–21 ksi, and 21+ ksi (83–145+ MPa), and these were tested according to ASTM C666, using 1.5% steel fibers. The samples were made for three different curing regimens: limewater curing in a fog room, simulated precast curing, and steam curing. Low-temperature differential scanning calorimetry (DSC) and mercury intrusion porosimetry (MIP) tests were carried out to reveal the freeze–thaw mechanism of the concrete samples. All mixtures with compressive strength above 15 ksi (103 MPa) performed excellent in freeze–thaw testing with no damage seen. Steam curing was found to negatively affect the freeze–thaw performance at the lowest strength level tested. Full article

This study presented a comprehensive finite element (FE) investigation into the flexural behavior of RC T-beams strengthened in the negative moment region using near-surface mounted (NSM) carbon-fiber-reinforced polymers (CFRP) rods. A three-dimensional nonlinear FE model was developed and validated against experimental data, achieving close agreement with normalized mean square error values as low as 0.006 and experimental-to-numerical ratios ranging from 0.95 to 1.04. The validated model was then employed to conduct a systematic parametric analysis considering CFRP rod diameter, concrete compressive strength, longitudinal reinforcement ratio, and FRP material type. The results showed that increasing CFRP diameter from 6 to 10 mm enhanced ultimate load by up to 47.51% and improved stiffness by 1.48 times. Higher concrete compressive strength contributed to stiffness gains exceeding 50.00%, although this improvement was accompanied by reductions in ductility. Beams with reinforcement ratios up to 2.90% achieved peak loads of 309.61 kN, but ductility declined. Comparison among FRP materials indicated that CFRP and AFRP offered superior strength and stiffness, whereas BFRP provided a more balanced combination of strength and deformation capacity. Full article

Riverbank erosion in the Vietnamese Mekong Delta (VMD) poses a serious threat to agricultural lands, infrastructure, and local communities. Conventional protective measures, such as synthetic geotextiles and concrete revetments, are often costly and environmentally disruptive. This study investigates the potential of Eichhornia crassipes, a widely available invasive species, commonly known as water hyacinth (WH), to produce biodegradable geotextiles as a low-cost, nature-based solution (NbS) for small-scale riverbank protection. It is the first to test minimally processed WH mats under simulated tidal conditions in the VMD. Laboratory experiments were conducted to evaluate the geotextile’s (1) sediment retention capacity, (2) wave energy reduction, and (3) mechanical durability under wet–dry cycles. Results show that the WH geotextile effectively reduced sediment resuspension, decreasing turbidity levels from 800 FTU (unprotected scenario) to below 50 FTU. The geotextile also attenuated wave energy, reducing significant wave heights by approximately 35–40%. Mechanical testing revealed that the fish bone weaving pattern with adhesive coating achieved the highest tensile strength (8.36 kN/m after 12 wet–dry cycles), while uncoated samples demonstrated higher elongation (up to 61.67%), providing greater flexibility. These demonstrate the feasibility of WH geotextiles as a scalable nature-based solution for erosion-prone tropical deltas. Future studies should focus on field-scale validation, biodegradation rates, and performance optimization for long-term applications. Full article

This study presents the design and performance assessment of suction anchor foundations for an integrated offshore wind–solar–aquaculture system located in Jiangsu Sheyang, China. The project represents one of the first practical demonstrations of coupling renewable energy production with large-scale marine aquaculture on a shared floating platform. Using three-dimensional numerical simulations in FLAC3D and ABAQUS, the study evaluates the anchors’ bearing capacity, structural safety, and fatigue performance under ultimate (ULS), accidental (ALS), and fatigue (FLS) limit states. The analysis incorporates site-specific geotechnical conditions, seabed scour, and installation deviations, providing a realistic framework for foundation design in layered coastal sediments. Results confirm that the suction anchor system meets international safety requirements (DNV, CCS) and maintains robust performance throughout its service life. The findings demonstrate that scour depth and installation accuracy are critical factors governing anchor reliability and offer practical insights for updating offshore foundation design standards in future multifunctional renewable–aquaculture developments. Full article

Explosions, including those from war weapons, terrorist attacks, etc., can lead to damage and overall collapse of bridges. However, there are no clear guidelines for anti-blast design and protective measures for bridges under blast loading in current bridge design specifications. With advancements in intelligent construction, precast segmental bridge piers have become a major trend in social development. There is a lack of full understanding of the anti-blast performance of precast segmental bridge piers. To study the engineering calculation method for blast load acting on a typical precast segmental reinforced concrete (RC) pier in near-field explosions, an air explosion test of the precast segmental RC pier is firstly carried out, then a fluid–structure coupling numerical model of the precast segmental RC pier is established and the interaction between the explosion shock wave and the precast segmental RC pier is discussed. A numerical simulation of the precast segmental RC pier in a near-field explosion is conducted based on a reliable numerical model, and the distribution of the blast load acting on the precast segmental RC pier in the near-field explosion is analyzed. The results show that the reflected overpressure on the pier and the incident overpressure in the free field are reliable. The simulation results are basically consistent with the experimental results (with a relative error of less than 8%), and the fluid–structure coupling model is reasonable and reliable. The explosion shock wave has effects of reflection and circulation on the precast segmental RC pier. In the near-field explosion, the back and side blast loads acting on the precast segmental RC bridge pier can be ignored in the blast-resistant design. The front blast loads can be simplified and equalized, and a blast-resistant design load coefficient (1, 0.2, 0.03, 0.02, and 0.01) and a calculation formula of maximum equivalent overpressure peak value (applicable scaled distance [0.175 m/kg^1/3, 0.378 m/kg^1/3]) are proposed, which can be used as a reference for the blast-resistant design of precast segmental RC piers. Full article

The complexities of megaprojects, particularly major transportation infrastructure projects (MTIs), require technological innovation that advances economic, social, and ecological objectives. Traditional engineering innovation emphasizes economic gains while neglecting sustainability. Therefore, implementing green innovation (GI) in MTIs is essential. This research examines key factors and correlations influencing MTI-GI to strengthen theoretical understanding and guide effective implementation. First, literature and interviews are used to identify MTI-GI influencing factors through the technology–organization–environment (TOE) framework. Second, an intuitive fuzzy number approach reduces subjectivity in expert scoring and, combined with the DEMATEL method, constructs a fuzzy DEMATEL model to quantify factor importance and identify critical drivers. Critical factors are then analyzed to formulate GI promotion strategies. Results reveal that MTI-GI influencing factors span technology, organization, and environment dimensions. Prioritizing green technological innovation and feedback mechanisms, optimizing organizational structures, and aligning with regional environmental characteristics are crucial for successful MTI-GI implementation. These findings support GI expansion in MTIs and offer targeted strategies for managing complex systems. Full article

This research investigates the influence of incorporating perlite aggregate and silica fume on the properties of cement mortar, with a focus on compressive strength, flexural strength, density, water absorption, and thermal conductivity. The results show that increasing the percentage of perlite (Pe) in the mixes causes a marked reduction in the compressive strength, reflecting the lightweight nature and low density of perlite. For mixes with Pe-20% through Pe-100%, the compressive strength decreased by up to 78% compared to the reference mix. However, the addition of silica fume (SF) in mixes with SF-20% to SF-100% partially offset this effect, limiting the strength losses to 18–71%, which indicates that silica fume contributes to strength enhancement over time. The flexural strength followed a similar trend, decreasing with a higher perlite content: reductions of up to 40% were observed for Pe mixtures, while SF mixes showed slightly smaller decreases, reaching 36%. The density also declined consistently with increasing perlite replacement, with a maximum reduction of 57% in mix Pe-100% due to the inherent porosity of perlite. The water absorption increased substantially in the same mix (Pe-100%), by 327% compared to the reference one, whereas the addition of silica fume (SF-100%) limited the increase to 181%, confirming its role in refining the pore structure. The thermal conductivity decreased with a higher perlite content, attributed to the formation of voids in the matrix. The lowest value was observed for Pe-100%, with an 82% reduction, while silica fume mixes also showed reductions of 37–81% relative to the reference mix. Based on a comprehensive evaluation of strength, density, water absorption, and thermal performance, mix SF-60% was identified as the optimal mixture, offering a balanced profile with a compressive strength of 4.4 MPa, thermal conductivity of 0.28 W/(m·K), and density of 1089 kg/m³. These performance levels make the developed mortars particularly suitable for non-load-bearing masonry units, lightweight blocks, and insulation panels, where reduced weight and enhanced thermal efficiency are essential. The study therefore provides practical guidance for the design of sustainable, lightweight mortars for energy-efficient construction applications. Full article

Earthquakes remain among the most destructive natural hazards, causing severe loss of life and property in seismically active regions such as Nepal. Major events such as the 1934 Nepal–Bihar earthquake (M_w 8.2), the 2015 Gorkha earthquake (M_w 7.8), and the 2023 Jajarkot earthquake (M_L 6.4) have repeatedly exposed the vulnerability of Nepal’s built environment. In response, the Ready-to-Use Detailing (RUD) guideline (NBC 205:2024) was introduced to provide standardized structural detailing for low-rise reinforced concrete buildings without masonry infill, particularly for use in areas where access to professional engineering services is limited. This study was motivated by the need to critically assess the structural performance of buildings designed according to such rule-of-thumb detailing, which is widely applied through owner–builder practices. Nonlinear pushover analyses were carried out using finite element modelling for typical configurations on soil types C and D, under peak ground accelerations of 0.25 g, 0.30 g, 0.35 g, and 0.40 g. The response spectrum from NBC 105:2020 was adopted to determine performance points. The analysis focused on global response, capacity curves, storey drift, and hinge formation to evaluate structural resilience. The maximum story drift for the linear static analysis is found to be 0.56% and 0.86% for peak ground acceleration of 0.40 g, for both three and four-storied buildings. Also, from non-linear static analysis, it is found that almost all hinges formed in the beams and columns are in the Immediate Occupancy (IO) level. The findings suggest that the RUD guidelines are capable of providing adequate seismic performance for low-rise reinforced concrete buildings, given that the recommended material quality and construction standards are satisfied. Full article

Conventional strengthening measures for existing structures are usually not effective for the self-weight, which accounts for around 70% of the total load in reinforced concrete structures. Therefore, their effect on the overall load-bearing capacity is low. A self-weight-effective alternative for flexural strengthening is the thermal prestressing of additional reinforcement installed on the structure. In this method, reinforcing bars are slotted into the tensile zone, embedded in filler material, and tempered from the outside. They are thermally stretched, and once cooling starts, the bond with the hardened filler prevents re-deformation. The induced prestressing force counteracts dead loads and relieves the tensile zone, making the additional bars effective for the self-weight. In this paper, the effectiveness of the strengthening method is experimentally investigated in the serviceability and the ultimate limit states. Experiments involve strengthening a reinforced concrete beam under load by a thermally prestressed additional bar. Moreover, two reference tests are made to evaluate the method. An unstrengthened beam characterizes the lower capacity limit. Another beam with the same reinforcement amount as the strengthened one, but completely installed at casting, serves as the upper benchmark. All beams are loaded until bending failure. The strengthening method is assessed by means of the load-bearing behavior, deflection, crack development, and the strains in the initial as well as the added reinforcement. The results demonstrate the effectiveness of the strengthening method. The thermally prestressed bar achieves an effective pre-strain of approximately. 0.4‰ by heating at about 70 °C. The induced prestressing force and associated compression reduce tensile cracks by approx. 45% and increase stiffness. The strengthened beam reaches the maximum load of the upper benchmark, but with about 33% less deflection. The filler, which also expands thermally, generates an additional prestressing force that is effective up to about 20% of the load capacity. Beyond this, the filler begins to crack and its effect decreases, but the pre-strain in the reinforcing bar remains until maximum load. Full article

This study presents the outcomes of a comprehensive experimental investigation focused on the bond behavior between reinforcing steel bars and tremie concrete, assessed through standardized pull-out tests. The objective was to evaluate the influence of some key parameters: reinforcement bar diameter, concrete age (and associated compressive strength), steel fiber content, and a bentonite coating on rebar surfaces. Experiments were conducted under laboratory conditions according to relevant standards. Slip between the reinforcement and tremie concrete was measured using a sophisticated high-precision optical laser device, enabling accurate assessment of bond characteristics. A large, i.e., a statistically sufficient, number of specimens was tested, allowing the results to be analyzed using the ANOVA technique to determine the statistical significance of each parameter. The results show that, under most test conditions, the influence of the bentonite suspension coating on the bond strength was not statistically significant. Similarly, variations in the bar diameter and fiber content showed no statistically significant impact within the tested ranges. In contrast, concrete age (compressive strength) exhibited a statistically significant influence, confirming that concrete maturity is a dominant factor in bond development. The results contribute to a better understanding of the bond mechanisms in reinforced concrete and can assist in optimizing design strategies where bond performance is critical. Full article