Civil Engineering Applications Research Articles

Investigation of Material Loading on an Evolved Antecedent Hexagonal CSRR-Loaded Electrically Small Antenna.

Recent advances in embedded antenna and sensor technologies for 5G communications have galvanized a response toward the investigation of their electromagnetic performance for urban contexts and civil engineering applications. This article quantitatively investigates the effects of material loading on an evolved antecedent hexagonal complementary split-ring resonator (CSRR)-loaded antenna design through simulation and experimentation. Optimization of the narrowband antenna system was first performed in a simulation environment to achieve resonance at 3.50 GHz, featuring an impedance bandwidth of 1.57% with maximum return loss and theoretical gain values of 20.0 dB and 1.80 dBi, respectively. As a proof-of-concept, a physical prototype is fabricated on a printed circuit board followed by a simulation-based parametric study involving antenna prototypes embedded into Ordinary Portland Cement pastes with varying weight percentages of iron(III) oxide inclusions. Simulation-derived and experimental results are mutually verified, achieving a systemic downward shift in resonant frequency and corresponding variations in impedance matching induced by changes in loading reactance. Finally, an inversion modeling procedure is employed using perturbation theory to extrapolate the relative permittivity of the dielectric loaded materials. Our proposed analysis contributes to optimizing concrete-embedded 5G antenna sensor designs and establishes a foundational framework for estimating unknown dielectric parameters of cementitious composites.

Non-Gaussian buffeting analysis of large structures by means of a Proper Orthogonal Decomposition

Proper Orthogonal Decomposition is implemented in a Bispectral Stochastic Analysis of large MDOF structures. Although Higher Order Stochastic Analysis has been introduced few decades ago, its establishment has found place only in a theoretical way, or applied to very small systems. Its heavy computational cost as well as resource consumption burden has let it aside for practical civil engineering applications. Nevertheless, in wind engineering, the community is increasingly considering the importance of non-Gaussian nature of wind induced vibrations. This is of interest for the extreme value analysis, for which many theoretical and empirical models exist for non-Gaussian random processes. In this context, a (bi-)spectral approach is realized in a 2-D frequency space where the bispectrum is computed then the 3rd statistical moment is obtained by means of a twofold integration. These operations are quite heavy as soon as the dimension of the problem increases. A novel algorithm implementation is proposed. It hinges on (i) the use of Proper Orthogonal Decomposition and the (ii) development of an optimized numerical method. The proposed algorithmic arrangement minimizes the number of operations, and consequently saves time and memory, while conserving precision in estimating 3rd order statistical moments of structural responses.

Flowshop scheduling optimization for multi-shift precast production with on-time delivery

With the increasing popularity of prefabricated construction around the world, precast plants face increasingly complex production scenarios. Because it is important for precast components to be delivered on time and assembled according to the planned schedule, it is a common phenomenon to increase production shifts and break the routine production schedule to meet time-pressured orders. But there is still a lack of research on flowshop multi-shift scheduling methods in precast production. To address this issue, a flowshop scheduling optimization model of multi-shift precast production with on-time delivery is established, which is the application in civil engineering. A solution framework and its corresponding optimization processes are designed to avoid a combinatorial explosion of solutions and save solution time, which is contribution in artificial intelligence. The validity of the model is proven using a practical case. The results show that, compared to the conventional scheduling method, the proposed method significantly reduces costs under on-time delivery and stably obtains optimized feasible scheduling schemes.

Fiber Bragg grating displacement sensor based on synchronous deformation sensing for real-time monitoring of a tunnel lining.

A fiber Bragg grating (FBG) displacement sensor based on synchronous sensing is developed for real-time monitoring of a tunnel lining. The sensing principle and mechanical structure of the proposed sensor are analyzed and simulated, and its sensitization effectiveness and temperature compensation are verified. Equivalent model tests show that the sensor has a good linear sensitivity of 19.48pm/mm and an excellent precision of 5.13×10-2 m m in the displacement range of 0-25mm, which is basically consistent with the simulation results. The key traffic parameters of the train were successfully obtained by real-time monitoring of the tunnel lining in a field trial, which shows the superior capability of micro-displacement measurement of the sensor. Furthermore, good stability and excellent creep resistance have also been demonstrated. Our results provide theoretical guidance for the fabrication and package of the FBG displacement sensor, which is valuable for structure health monitoring (SHM) in civil engineering applications.

Mine waste rock reprocessing using sensor-based sorting (SBS): Novel approach toward circular economy in phosphate mining

Phosphate extraction and processing generates large volumes of phosphate mine waste rock (PMWR) that still contains non-negligible amounts of residual phosphate. Due to the increasing demand for phosphorous (P), in particular by the fertilizer industry, PMWR can become a potential resource for P beneficiation if cost-effective methods are applied. The main objectives of this study are to:i)characterise PMWR from the Ben Guerir mine site (Morocco);ii)evaluate the efficiency of hand- and sensor-based sorting (SBS) to recover the lost phosphate; and.iii)upgrade the P2O5 content in the concentrate.Samples were collected from different locations in the PMWR piles and divided into two main fractions: >30 mm and < 30 mm. The coarse fraction (>30 mm) was sorted using three main SBS technologies to separate phosphate from gangue materials: dual energy X-ray transmission (DE-XRT), near-infrared combined with color (NIR/color), and color technologies. The fine fraction was processed with the conventional flowsheet used by the mine.Chemical and mineralogical characterisation showed that the composite sample contained up to 17.5 wt% P2O5, with an abundance of fluorapatite, calcite, quartz, and dolomite. The hand sorting demonstrated that >50 wt% of the PMWR within the coarse fraction (>30 mm) was in the form of indured phosphate (IndP). The remaining lithologies were represented by phosphated flint, flint, silexite, limestone, and marl. In terms of sorting efficiency, the tests highlighted the performance of DE-XRT for materials characterised with a difference in atomic density. The use of DE-XRT allowed a P2O5 recovery of 70 wt%, with an increase of the P2O5 content from 13.5 wt% to 18.5 wt%. The remaining lithologies were successfully separated using SBS technologies. Materials sorting is an interesting technology that can reduce the environmental footprint of PMWR by recovering the lost phosphate and valorising the remaining lithologies for civil engineering applications.

Sustainable transformation of end-of-life wind turbine blades: Advancing clean energy solutions in civil engineering through recycling and upcycling

Decommissioning end-of-life wind turbine blades (EoL-WTBs) presents significant waste management challenges. This comprehensive review explores the recycling of EoL-WTBs and their potential application in civil engineering for its clean development. This work examines the treatment of decommissioned wind power systems, the growth and management of WTBs waste, recycling technologies, and the development of cutting-edge approaches. The review emphasizes mechanical, thermal, and chemical recycling methods for EoL-WTBs and their corresponding recycled products. It highlights the hierarchical valorization of EoL-WTBs recyclates in construction, including their use as fillers, concrete reinforcement fibers, and supplementary cementitious materials. These applications offer substantial absorption pathways for reusing EoL-WTBs recyclates and contribute to the decarbonization and sustainability of the construction industry. However, challenges such as technical complexity, cost, market demand, and regulatory frameworks hinder the widespread adoption of EoL-WTBs recycling. To effectively address these issues, the review recommends establishing practical implementation plans through standardization, efficient transportation systems, well-structured recycling supply chains, and thorough economic feasibility analysis. In conclusion, this review underscores the significant potential of EoL-WTBs recyclates in civil engineering and sheds light on critical avenues for future research.

Geological and Geomechanical Characterization of Phosphate Mine Waste Rock in View of Their Potential Civil Applications: A Case Study of the Benguerir Mine Site, Morocco

Sedimentary phosphate extraction in open-pit operations generates large volumes of waste rock (WR), which are mainly overburdens and interburdens. Traditionally, the WR is mixed and stored on the surface in waste rock piles (WRPs). This paper presents a case study of the Benguerir mine site in Morocco. It investigates the potential valorization of each WR lithology based on the geological and geomechanical properties to reduce their environmental footprint and create added value to “waste.” The WR samples (soils and rocks) were collected from drill cores and mining trenches in the Benguerir mine. The geological characterization results using petrographic descriptions indicate the presence of nine phosphate layers and, in addition to the overburdens, eight interburdens. Four types of WR are identified: carbonate, siliceous, marly clay, and phosphate. The geomechanical characterization of soil-like samples showed an average plasticity index (PI) of 50% according to the methylene blue value (MBV) of 7.1, classifying them in the A3–A4 categories as plastic and clayey marl soils. The hard rock samples have excellent mechanical properties in terms of their uniaxial compressive strength (UCS), Los Angeles abrasion value (LA), and micro-Deval value (MD). The average compressive strength is 104 MPa for the flint, 35 MPa for the phosphate flint, 32 MPa for the silexite, 26 MPa for the limestone, 11 MPa for the indurated phosphate, and 8 MPa for the marly limestone. Based on the obtained results, these WRs can be considered as an excellent alternative secondary raw material for use in civil engineering applications, ceramics, and cement industries.

A star-shaped tubular structure with multiple-directional auxetic effect

A majority of tubular structures have been widely studied due to their superior mechanical performance. Existing works on star-shaped tubular structures have focused on improving their stability and energy absorption performance. This paper proposes a novel star-shaped tubular lattice structure (STL), which not only possesses excellent mechanical properties but also exhibits exceptional auxetic effect. In addition, such structures exhibited two distinct deformation modes under different loading directions. Numerical and experimental studies of the mechanical behavior of the star-shaped tubular structure demonstrated low peak stresses under lateral loading and superior bearing capacity and stability under axial compression. Most importantly, the structure embodied a significant auxetic effect under the direction of both loads. The mechanical performance of the star-shaped tubular structures was investigated by changing wall thickness and angles, which can realize the optimal design. This study enriches the research on star-shaped tubular structures and provides a new perspective and reference for the design of auxetic tubular metamaterials in the future. Furthermore, the star-shaped tubular structure with auxetic behavior has considerable potential for applications in civil engineering and protective fields.

Research on the fiber reinforced polymer in new construction and in strengthening of steel structures

Due to their distinct advantages, fiber-reinforced polymer (FRP) composites gained popularity during the past 200 years in civil engineering area, including high durability, corrosion resistance, light weight, high modulus strength, and high quality of corrosion resistance. These ranges of features led FRP composites find their application in mechanical, structure, civil engineering, and other industries areas. Traditional construction materials such as steel cannot feed the desirable expectation, and these high-tech materials are becoming more and more popular to replace the traditional materials. By analyzing experiments conducted by other scholars, the following essay will provide a critical review of FRP’s use in strengthening steel structures, not only for its advantages but also for its disadvantages and material properties. After the research, more experiments and theoretical research should be done to let FRP strengthen-materials be accepted and widely used in industries, as FRP materials still have some drawbacks.

A Method for the Precise Coordinate Determination of an Inaccessible Location.

Surveyors are occasionally tasked to with determining the coordinates of inaccessible locations or points in civil engineering applications, ground control points for photogrammetry or LiDAR data acquisition, among others. The present work outlines and investigates a novel method for estimating the GNSS coordinates of an inaccessible location where a surveying instrument cannot be set up. The procedure is based on the well-known surveying intersection method and data extracted from an Earth Gravity Model (e.g., EGM 2008). The location's coordinates are obtained from the least-squares adjustment of the angles and distances measured from at least two sites to the unknown point using a total station, within the framework of the Gauss-Helmert method. Field tests confirmed that the accuracy of the determined coordinates of the inaccessible point is at the level of 1 cm. The proposed method bypasses standard coordinate transformation steps performed with the traditional approach, directly producing geocentric coordinates of the unknown points.

The Role of Artificial Intelligence in Civil Engineering Applications and Programs

The integration of artificial intelligence (AI) techniques in civil engineering programs and drawing techniques has the potential to revolutionize the industry. This study explores the benefits, challenges, and strategies for the effective utilization of AI in civil engineering. The research investigates the current state of AI integration, examines its applications in structural analysis, design, documentation, and project management, and identifies the barriers hindering widespread adoption. The study highlights the importance of data-driven decision-making, enhanced design visualization, improved accuracy and efficiency, streamlined documentation and communication, and enhanced project management and control. By addressing the challenges and providing insights into AI techniques, this study aims to bridge the gap between theoretical potential and practical implementation, paving the way for more sustainable and intelligent civil engineering projects.

Dynamic mode I fracture characteristics of jute fiber-reinforced rubber mortar

Rubber mortar (RM) is an environmentally friendly cement adhesive material with high energy absorption. However, rubber significantly weakens the fracture properties of mortar. Jute fibers have been incorporated as environmentally friendly fibers to address this issue. This study investigated the dynamic mode I fracture characteristics of jute fiber-reinforced rubber mortar (JFRRM) with six jute contents. The results demonstrated that the jute fibers altered the internal microstructure and enhanced the dynamic mode I fracture properties of JFRRM, with a 1.2% jute fiber content yielding the highest fracture toughness. Therefore, JFRRM can be used for green civil engineering and other applications.

Mesoscopic analysis and intra-layer progressive failure model of fused filament fabrication 3D printing GFRP

The deficiency of failure analysis methods severely hinders the civil engineering application of Fused Filament Fabrication (FFF) 3D printing composites. In order to comprehensively investigate the failure process, this paper innovatively proposes the concept of continuous printing filament hypothesis based on mesoscopic analysis. This hypothesis serves to characterize the interconnection status between glass fiber reinforced polymer (GFRP) filaments during FFF 3D printing. Building upon this hypothesis, a progressive failure model is established, which can predict the intra-layer failure process under axial quasi-static load accurately. In the failure model, both Mode-2D and Mode-3D failure criteria are employed to pinpoint intra-layer damage initiation, while damage evolution is depicted using a stiffness reduction mode based on the fracture energy criterion. Simultaneously, the fundamental orthotropic mechanical parameters are examined, and 24 variations of printing laminates are meticulously designed. The ultimate tensile strengths (UTS), encompassing both cross-stacking (2/8, 4/6, 5/5) and angle-stacking (30°, 45°, 60°), are tested and simulated using the progressive failure method established during this study. Experimental results show that the lower layers of composites exhibit stronger ultimate resistance due to their layer-by-layer characteristics. Compared to the experimental results, all the relative errors of UTS predicted by Mode-3D are less than 15%. Therefore, the accuracy and predictive capacity of the progressive failure model are affirmed by the experimental data.

Simulation-Based Model-Updating Method for Linear Dynamic Structural Systems

The dynamic characteristics of buildings and their behavior under various dynamic loads play a crucial role in civil engineering applications, particularly for earthquake-resistant structural design. Employing a precise mathematical model of the structural system makes it possible to accurately predict the actual structural performance under dynamic loads, such as winds and earthquakes. Given this perspective, finite element model-updating approaches in structural systems have gained significant attention in recent decades. This paper proposes a simulation-based model-updating technique that utilizes measured free vibration responses to the correct structural parameters of multi-degree-of-freedom systems. A five-degree-of-freedom building model is subjected to shaking table tests to demonstrate the effectiveness of the proposed method. The experimental data for this method consists of the dynamic behavior of the system under the seismic excitation of the El Centro 1940 earthquake and the results of the free vibration tests. The MATLAB/Simulink parameter estimation tool is employed to establish a correlation between the analytical model and the measured dynamic response from the building model. Compared to the measured structural responses, the updated analytical model, which incorporates the proposed simulation-based model-updating technique, demonstrates high accuracy in predicting the responses through effective corrections of stiffness and damping coefficients.

Mechanical Properties and Durability of Textile Reinforced Concrete (TRC)-A Review.

Textile reinforced concrete (TRC) is an innovative structure type of reinforced concrete in which the conventional steel reinforcement is replaced with fibre textile materials. The thin, cost-effective and lightweight nature enable TRC to be used to create different types of structural components for architectural and civil engineering applications. This paper presents a review of recent developments of TRC. In this review, firstly, the concept and the composition of TRC are discussed. Next, interfacial bond behaviour between fibre textile (dry and/saturated with polymer) and concrete was analysed considering the effects of polymer saturation, geometry and additives in polymer of the textile. Then, the mechanical properties (including static and dynamic properties) of TRC were reviewed. For static properties, the mechanical properties including compression, tension, flexural, shear and bond properties are discussed. For dynamic properties, the impact, seismic and cyclic properties were investigated. Furthermore, the durability of TRC under different environmental conditions, i.e., temperature/fire, humidity and wet-dry cycles, freeze-thaw, chemical and fatigue were discussed. Finally, typical engineering applications of TRC were presented. The research gaps which need to be addressed in the future for TRC research were identified as well. This review aims to present the recent advancement of TRC and inspire future research of this advanced material.

Towards Probabilistic Robust and Sparsity-Free Compressive Sampling in Civil Engineering: A Review

Compressive sampling (CS) is a novel signal processing paradigm whereby the data compression is performed simultaneously with the sampling, by measuring some linear functionals of original signals in the analog domain. Once the signal is sparse sufficiently under some bases, it is strictly guaranteed to stably decompress/reconstruct the original one from significantly fewer measurements than that required by the sampling theorem, bringing considerable practical convenience. In the field of civil engineering, there are massive application scenarios for CS, as many civil engineering problems can be formulated as sparse inverse problems with linear measurements. In recent years, CS has gained extensive theoretical developments and many practical applications in civil engineering. Inevitable modelling and measurement uncertainties have motivated the Bayesian probabilistic perspective into the inverse problem of CS reconstruction. Furthermore, the advancement of deep learning techniques for efficient representation has also contributed to the elimination of the strict assumption of sparsity in CS. This paper reviews the advancements and applications of CS in civil engineering, focusing on challenges arising from data acquisition and analysis. The reviewed theories also have applicability to inverse problems in broader scientific fields.

Numerical Simulation of Geotechnical Isolation of Building Subjected to Earthquake Using Rubber Sand Mixtures

The use of recycled rubber in various civil engineering applications has seen a considerable rise in recent years. The rubber-soil mixture can exhibit a higher energy absorption capacity than soil alone, which would reduce the energy applied to structures, the stresses, and shocks they undergo. Base isolation is the process of isolating the base of a structure to limit the effects of earthquakes, so that the seismic forces applied to the base of the bedrock cannot move with the same intensity towards the super structure.In this work, the beneficial effects of rubber mixtures (RSM) in mitigating earthquakes when these mixtures are inserted as layers in the soil profile are highlighted; the approach is based on a method of using worn tires for seismic protection applications for infrastructures subjected to seismic loads. It involves mixing particles from used tires with soil materials and placing the mixtures under the foundation of the building as geotechnical insulation systems for vibration absorption.The foundation of a four-storey building is implanted in a soil profile in which a layer of rubber-sand mixture (RSM) has been inserted; to perform the role of seismic isolation when subjected to seismic excitation.The investigation is focused on the variation in the thickness of the layer on the one hand (between 1m and 4m), and on the other hand on the position of this layer in the soil mass (top, middle and bottom of the profile).The peaks of horizontal accelerations recorded at the base and top of the structure show that the sand-rubber mixture has adequate and promising potential for their application as seismic isolation materials for low-rise buildings. Moreover, the thickness of the layer and its location are two very determining parameters in the improvement of the performances of these RSM mixtures, especially in terms of reduction of the acceleration peak recorded.

Optimizing the Monotonic Properties of Fourth-Order Neutral Differential Equations and Their Applications

We investigate the oscillation of the fourth-order differential equation for a class of functional differential equations of the neutral type. We obtain a new single-oscillation criterion for the oscillation of all the solutions of our equation. We establish new monotonic properties for some cases of positive solutions of the studied equation. Moreover, we improve these properties by using an iterative method. This development of monotonic properties contributes to obtaining new and more efficient criteria for verifying the oscillation of the equation. The results obtained extend and improve previous findings in the literature by using an Euler-type equation as an example. The importance of the results was clarified by applying them to some special cases of the studied equation. The fourth-order delay differential equations have great practical importance due to their wide applications in civil, mechanical, and aeronautical engineering. Research on this type of equation is still ongoing due to its remarkable importance in many fields.

Hydrothermal aging of carbon fiber reinforced polymer rods intended for cable applications in civil engineering

Carbon fiber reinforced polymer (CFRP) composites have become increasingly popular due to their high strength-to-weight ratio and excellent mechanical properties. However, CFRP composites are susceptible to hydrothermal aging when used as cable applications in civil engineering, which can cause irreversible damage to their service performance. In this study, the effects of water immersion (water@60 °C), constant temperature and humidity exposure (95%RH@60 °C), and alternating hydrothermal environment (12h_60 °C&12h_25 °C@95%RH) were investigated on the property degradation of the CFRP rods. In addition, the water absorption behavior, and thermal and mechanical properties of the CFRP rods were systematically analyzed and compared. We found that elevated temperature and humidity accelerated the water absorption process, resulting in to the higher equilibrium moisture content and diffusion coefficient. Hydrothermal exposure led to maximum degradation in the tensile strength, three-point bending strength and short-beam shear strength of CFRP rods, with values reaching 4.8%, 17.4% and 24.3% in the water@60 °C, 95%RH@60 °C, and 12h_60 °C&12h_25 °C@95%RH conditions, respectively. Among the three mechanical performance properties analyzed, the tensile strength degradation of the CFRP rods was least affected by the three environmental conditions, primarily due to the tensile direction along the carbon fibers. In addition, the three-point bending and short-beam shear strength values of the CFRP rods showed the greatest degradation in the 12h_60 °C&12h_25 °C@95%RH environment. The long-term effects of the water molecules against the CFRP rods in the hydrothermal environment caused resin hydrolysis and debonding of the fiber-matrix interface, leading to degradation in three-point bending and short-beam shear strength. Additionally, the temperature alternating factor accelerated the degradation of the mechanical properties of the CFRP rods, and the mechanical properties of the CFRP rods declined most noticeably with alternating temperatures under the same moisture content conditions.

Preface

International Conference on Sustainable Practices in Engineering & Technology (IC-SPET’23) is the AICTE sponsored first international Conference organised by Department of Civil Engineering of Sree Buddha College of Engineering, Pattoor, from 14th to 16th June, 2023 with a focal theme on Sustainability in Civil Engineering. The sub themes were Structural Engineering & Sustainable Construction Technology, Water Resource & Environmental Engineering, & Transportation Engineering, Modelling & Computational Techniques in Civil Engineering and GIS application in Civil Engineering. The conference is planned and organized with an objective of providing a platform and conducive environment for the participants to share innovations in Engineering and Technology and to form international relationships among the researchers involved in Engineering and Technology.The three-day international conference was conducted from 14th June, 2023 to 16th June, 2023 in hybrid mode. The conference was inaugurated by the chief guest Dr. N.P. Rajamane, Professor, Scientist, Founder & Former Head (a) Centre for Advanced Concrete Research (CACR), SRM IST (b) Advanced Materials Lab (AML), CSIR-SERC. Renowned national and international speakers such as Dr. N. P. Rajamane (Scientist, Founder & Former Head - (a)CACR, SRM IST (b) AML, CSIR-SERC), Dr. Kamal Laksiri (Governor, Region 10, ASCE), Dr. Sumi Siddiqua (Associate Professor, The University of British Columbia, Canada), Dr. Tanmay Basak (Professor, Indian Institute of Technology Madras) and Dr. Vinu Unnikrishnan (Assistant Professor, College of Engineering, West Texas, USA) has delivered keynote address on sustainable practices in diverse fields of engineering.To IC-SPET’23, 103 technical papers from various institutions within and outside the state were submitted, out of which 65 papers accepted for presentation. And 17 papers were selected to include in this proceeding of conference through meticulous review process performed by experts in the field.We would like to greatly acknowledge the active contribution of keynote speakers, session chairs, reviewers, authors and participants towards the success of the conference. We express our indebted gratitude to Prof. K. Sasikumar, Hon'ble Chairman of the Sree Buddha Group of Institutions, Prof. V. Prasad (Secretary) and Sri. A. Sunil Kumar (Treasurer) of the Sree Buddha Educational Society, Dr. K. Krishnakumar, the Principal of Sree Buddha College of Engineering and all members of Sree Buddha Educational Society for their invaluable guidance and support for the successful coordination of the event. We appreciate the efforts of the faculty members, staff, and student volunteers of the Department of Civil Engineering, who worked as a team and shared responsibilities for the successful coordination.We would like to acknowledge the financial assistance received from AICTE (All India Council for Technical Education) for organizing the conference. We express our sincere gratitude to all the associating organisations and institutions such as ASCE, IEI Kollam local center, ICI Kochi center, Habilete learning solutions, Indian Institute of Infrastructure and Construction, Qcrete and T. R. Associates for their timely assistance. Finally, we express our sincere thanks to the team of IOP Conference series lead by Cat Leyland and Rachelle Morris for bringing out this proceedings.