Civil Engineering Applications Research Articles

Rheological enhancement of fresh polymer-modified cement composites via surface-modified graphene oxide

Polymer-modified cement (PMC) composites are extensively utilized in modern construction, especially in tunneling and structural applications, but their excessive flowability and reduced thixotropy continue to present fundamental rheological challenges. We present a novel approach to improving the rheological performance of PMC via surface-modified graphene oxide (GO), i.e., GOPMC composites. Specifically, the flow behavior of GOPMCs in relation to shear stress–shear strain response and apparent viscosity were investigated. The rheological parameters were analyzed by using Herschel–Bulkley's model. Additionally, zeta potential and dispersion analysis were conducted to investigate interparticle interaction forces. Flow measurement confirmed ∼20 % lower flowability of the GOPMC than the reference PMC. GOPMC composites further displayed higher yield stress of ∼82 % and ∼33 % reduced viscosity with inherent decreased shear-thickening compared to reference PMC composites. The yield stress of the GOPMC composite increased over time, disclosing distinct structural evolution linked to enhanced hydration kinetics by GO. Additionally, GO nanosheets in the GOPMC altered the rheopectic behavior of the redispersible polymer and enhanced the degree of thixotropy by ∼80 %, attributable to the promotion of bridged flocculated structures which produces a rigid system, facilitated by particle interaction forces comprising of van der Waals and steric forces. This latter observation provides a mechanistic framework for the enhanced rheological performance of GOPMC composites aiming at broader civil engineering and construction sector applications beyond tunneling.

Stability of porous orthotropic laminated cylindrical panels subjected to linearly varying edge compression based on shear deformation theory

This study investigates the stability characteristics of porous orthotropic laminated cylindrical panels under the influence of linearly varying edge compression, employing the higher-order shear deformation theory. Four porosity distribution patterns along the laminate thickness are considered to model porous material properties. Theoretical formulations and numerical methods are utilized to evaluate critical buckling loads and mode shapes. The effects of parameters such as porosity, distribution patterns, orthotropy, radius-to-side ratio, aspect ratio, and side-to-thickness ratio on stability characteristics are examined. The research contributes to composite materials and structural stability analysis with potential aerospace, marine, and civil engineering applications.

Interpretation of vertical electrical soundings by means of ISM, PHT and C-N, case of a ditch in Al-Sharquieh phosphate mine in Syria

The main objective of this paper is basically to calibrate and compare the different geoelectrical results obtained by the three interpretative techniques of the inverse slope method (ISM), Pichgin and Habibuleav (PHT) and concentration-number (C-N) fractal modeling with the well lithology of an existing known ditch in the Al-Sharquieh phosphate mine in Syria. Those interpretative techniques are applied herein to interpret the vertical electrical soundings (VES) points measured along a parallel profile to the ditch. ISM reveals the presence of four to five geoelectrical layers in the study region. The PHT allows the determination of the tectonic subsurface features of the study region, by analyzing the non homogeneity points and their distributions along a given geoelectrical profile. The fractal C-N modeling provides the different apparent resistivity ranges dominating in the study region. Good agreements are obtained between the direct observed field lithological descriptions of both wall sides of this ditch, and the results obtained by those three interpretative geoelectrical techniques. The high radioactive readings exceeding four hundred count per second (cps) are due to the presence of secondary uranium accompanied with fractures, cracks and joints. The secondary uranium occurrences accompanied by phosphate deposits are found in the study area in the fractured zones, as determined by the geoelectrical PHT technique. The three mentioned geoelectrical methodologies are therefore used as indirect techniques for delineating the radioactive zones related to uranium prospecting. It is a successful application of the joint use of those three techniques, that could be applied in mining to delimit the subsurface geological structure. The reliability and efficacy of (ISM), (PHT), and (C-N) fractal modeling techniques are consequently well confirmed, and it is therefore recommended to use and apply them for characterizing and describing similar lithological phosphatic sequences, and for several shallow mining, environmental and civil engineering applications.

Mechanical Properties and Water Permeability of Textile-Reinforced Reactive Powder Concrete with Lightweight Aggregate.

This paper focuses on the development of thin-walled panels with specific properties for applications such as water-tight structures. The authors propose the use of textile-reinforced concrete (TRC) as a composite material and highlight its advantages, which include high tensile strength, improved crack resistance, and design flexibility. The study presents a novel approach which combines TRC with reactive powder concrete (RPC) as a matrix and a lightweight aggregate. RPC, known for its brittle behaviour, is reinforced with glass fibres and a textile fabric to increase its flexural strength. The research includes a comprehensive analysis of the physical and mechanical properties of both the unreinforced RPC matrix and the TRC composite. In particular, the lightweight aggregate RPC matrix has a porosity of 41%, and its mechanical properties, such as flexural and compressive strength, are discussed. The TRC composites, produced in thicknesses ranging from 1 mm to 4 mm, are subjected to flexural tests to evaluate their behaviour under load. The thicker elements show typical damage phases, while the thinner elements show greater flexibility and elasticity. SEM observations confirm good adhesion between the glass fibres and the RPC matrix. Water permeability tests show that the TRC composite, despite its highly porous structure, achieves a water permeability two orders of magnitude higher than that of a reference material, highlighting the roles of both the porous aggregate and the matrix hydration. The paper concludes with a proof of concept-a canoe called the PKanoe, which is constructed from the developed TRC composite. The design of the canoe is supported by numerical analysis to ensure its optimal shape and structural integrity under load. The research contributes to the exploration of innovative materials for sustainable civil engineering applications and addresses both structural and environmental considerations.

Highlighting the use of end-of-life tire (ELT) as a renewable material and the potential applications in Indonesia

The development of the number of vehicles impacts the increased waste of used tires produced. This paper was created to explore the reuse end of life tires (ELT) as a renewable material. This paper also discusses the potential implementation of tire fiber recycling in Indonesia. Data were taken from various relevant articles from accredited sites such as Elsevier, Springer, Scopus, and Research gate. The data were reviewed using the narrative analysis method. Two recycling sectors, namely geotechnical application (Landfill liner) and civil engineering application (asphalt, pavement, LVL board, and lightweight aggregate concrete). The result shows the potential for ELT applications in Indonesia is very high. This is due to the large number of used tires in Indonesia because of the high consumption of vehicles by the population. The new recycling process carried out in Indonesia is only asphalt and pavement. There is no use of ELT for landfill liners, LVL, and lightweight aggregate concrete in Indonesia. The utilization of ELT can be maximized in Indonesia with the help of local government and research studies to reduce ELT waste in Indonesia.

Numerical investigation of steel beams with web openings obtained from topology optimisation

The use of web openings in I-section beams has become increasingly common in recent years, and these elements can be observed in various civil engineering applications. This design approach results in an improved weight-to-stiffness ratio in steel beams, enabling their use over longer spans without a significant increase in material cost and deflections due to self-weight. It also avoids the cutting of holes in inappropriate locations for electrical, hydraulic, and air conditioning installations. Steel beams fabricated with web openings also represent an important solution when height constraints are imposed on multi-story buildings due to design regulations and economic considerations. It is recognised that the use of the traditional web opening shapes - namely, circular, rectangular, and hexagonal - in civil structures can lead to issues associated with high stress concentration. The presence of these web openings can induce local instability or yielding due to inadequate shear force transfer across the openings, allowing plastic hinge formations, also known as Vierendeel mechanism, for instance. In this sense, researchers have investigated novel shapes to mitigate the impacts of the web openings in both structural and economic terms. In this sense, this work has been developed aiming to evaluate the structural performance of I-section beams obtained using structural optimisation, for a reference distributed load and different boundary conditions, compared with the cellular beams. An evaluation of the structural potential of the obtained topologies has been performed by linear elastic, buckling and complete nonlinear analyses. Results were obtained in terms of stresses, displacements, and ultimate loads for all investigated cases. It was found that when compared to a cellular beam, the optimised beams increased the ultimate resistance with superior stiffness resulting in lower displacements and presented a more adequate stress distribution with lower stress concentration. However, in some cases a poor structural performance was observed due to large zones with holes obtained from the optimisation process. Based on these results and on the work of Tsavdaridis et al., authors proposed a configuration for the openings, and its structural performance proved it to be a promising solution to be employed on beams with web openings, especially when the expected failure mode is lateral-torsional buckling. A parametric study was conducted to assess the efficiency of the proposed configuration for different steel profiles and span lengths; results indicated equivalent or superior load capacity when compared to the reference cellular beam. The configuration suggested by the authors can be easily fabricated, and, considering the constant patterns along the length, finding an expression to determine its design load is possible, like what is usually done for other shapes (circular, hexagonal).

Study on effects of TiO2 Nano particles on properties of concrete

Civil Engineering is one of the vast specializations that required an advanced research to utilize the current trend in Nano technology especially utilizing eco-friendly Nano materials for various constructions such as roads, building, soil stabilization and backfill material treatment. Nanomaterials enhance the strength, durability against aggressive chemical compounds and elements that extend the effective service life of the structure. Nanomaterials can also help to reduce the need for raw materials for upkeep and repair. In particular for heavy-duty applications, Nano materials are crucial in the development of high-strength and low-energy buildings. The outcomes of laboratory and field experiments on the effects of Nano materials on the environment are also thoroughly analyzed. There are many different types of Nano particles accessible nowadays, but TiO2 was chosen for this investigation. There are several civil engineering applications for this, to investigate how mechanical properties (compressive strength and flexure strength) are affected by TiO2 Nano particles (NT). In this investigation, M30grade concrete with TiO2 at 0.2, 0.4, 0.6, and 0.8 percent by adding to the weight of cement was used.

Multiphysical numerical analysis for acoustic metamaterials in ventilated ducts

In recent decades, metamaterials have shown interesting properties in the acoustic, mechanical, and aerospace engineering fields. The characteristic tunability on targeted bandwidth and the freedom of design have lately extended the metamaterial application in the multiphysical domain, for example, achieving systems that simultaneously allow noise insulation and fluid passage. Numerical methods such as FEM has been validated to test single metamaterial physics issue, and lately, mixed physics have been exploited for research and industrial purposes. However, there is still no precise method to follow when tuning acoustic metamaterials (AMMs) with different flow conditions in a multiphysical domain. For this reason, in this study, a Multiphysical FEM is evaluated to assess the implications of different flow characteristics on acoustic performance. First, two mono-physical models separately evaluate the fluid dynamic and acoustic problem. The two physical numerical models are then combined in the second stage, and a correlation between the two approaches (mono and multi-physical) is drawn. These preliminary results could be applied to many flow and frequency range case studies and implemented for Mechanical and Civil Engineering applications.

Time-moisture superposition principle in creep behavior of white oak with various earlywood vessel locations

Creep behavior of wood plays a fundamental role in precision processing of wood. In this work, experimental creep tests have been conducted to determine the influence of earlywood vessel location and moisture content on creep behavior of Quercus alba (white oak). Time-moisture superposition principle was applied to predict long-term creep behavior of white oak. Results revealed that both of instantaneous and 45-min strain of specimens increased with the increasing of moisture content and decreased with increasing distance between earlywood vessel belt and load-bearing surface significantly. Additionally, the time-moisture superposition principle was found to have feasibility to predict creep behavior of white oak with various earlywood vessel locations and moisture content ranges (6 % - 18 %). We believe that the proposed investigation was beneficial for the processing precision and civil engineering applications of wood.

Photocatalytic Applications of SnO2 and Ag2O-Decorated SnO2 Coatings on Cement Paste

Recently, the production of new photocatalytic materials has attracted considerable attention as a promising strategy to mitigate anthropogenic environmental degradation. In this study, cement paste composites (water/cement ratio = 0.5) were prepared using a coating based on nanoparticles of SnO2 (SnO2/cement paste) and SnO2 decorated with Ag2O (Ag2O-decorated SnO2/cement paste) for photocatalytic applications. These coatings were prepared in this study by using the hydrothermal method as the strategy. Thus, photocatalyst efficiency was evaluated through the degradation of methylene blue (MB) and methyl red (MR) as cationic and anionic dyes, respectively, and the simultaneous degradation of MB/MR (1:1 v/v) dyes. Moreover, the photocatalytic mechanism was investigated in the presence of scavengers. Notably, an increase in pH in the range of 2–6 resulted in selective degradation of the MB/MR dye mixtures. Overall, the photocatalytic performance of these materials provides a novel platform technology focused on advanced civil engineering applications, which consequently facilitates the mitigation of various environmental problems.

Combustion Assisted Synthesis of CuO Nanoparticles and Structure-Property Evaluation in nano-CuO Polymer Composites

Metal oxide-based nanoparticle as a filler in epoxy polymer composites has diverse applications in various industries, including adhesives, automobiles, aerospace, wind energy, and civil engineering. However, these composites must fulfill essential properties encompassing chemical, curing, optical, and thermal attributes. This study focuses on enhancing epoxy polymer by integrating copper oxide (CuO) nanoparticles synthesized through solution combustion. Varied CuO loadings (0.5–2.5 wt.%) were impregnated into the epoxy, critically impacting the structural attributes of the resulting nano-CuO polymer composites. Various material characterization techniques were employed to study the synthesized materials' morphology, elemental composition, phase formation, identification of the presence of functional groups, thermal stability, and optical properties. SEM images show the presence of spherical particles with porous structures. EDX confirmed the presence of Cu and O elements, while the XRD pattern showed the formation of CuO with an average crystallite size of 46 nm. FTIR confirms the presence of O-H, C-H, and C=C functional groups. TGA showed thermal stability and revealed minimal mass loss below 250 °C for nano-CuO polymer composites and minimal mass loss occurred for CuO nanoparticles at 900 °C. Photoluminescence exhibited redshifted luminescence spectra. The study suggests improved qualities due to CuO nanoparticle integration into epoxy. CuO loading crucially influences nano-CuO polymer composite properties, rendering them ideal for high-temperature applications, supported by remarkable thermal stability evidenced by substantial residual mass in TGA.

The Prospects of Building Information Modeling (BIM) and Intelligent Construction in Civil Engineering for Digital Transformation

This paper explores two significant technologies, Building Information Modeling (BIM) and Intelligent Construction, in the context of digital transformation in the field of civil engineering. Firstly, the definition, principles, and importance of BIM are introduced, along with its applications in design, construction, and project management. Subsequently, the definition, key features, advantages, and case studies of Intelligent Construction in civil engineering are discussed. The integration of BIM and Intelligent Construction is then examined, including the synergies between the two, potential applications in civil engineering, and the enhanced project planning, collaboration, and efficiency resulting from the integration. Finally, the future outlook and challenges of BIM and Intelligent Construction are presented, along with strategies for promoting their widespread adoption and implementation.

Stainless steel I-section beams subjected to combined torsion and bending: Experimental results

In this paper, the details of an experimental program, during which fabricated stainless steel I-section beams subjected to combined bending and torsion are tested, are presented. The test specimens consisted of 10 laser welded austenitic (EN 1.4307 and EN 1.4404) and traditionally welded duplex (EN 1.4162) beams of different cross-sectional dimensions and lengths. The experimental boundary conditions idealized a simply supported beam loaded at mid span with a transverse force applied away from the shear centre, leading to combined torsion and bending to model civil engineering applications. During the tests, the rotations were measured using inclinometers as well as Digital Image Correlation, while strains were measured using strain gauges. Mid span rotations of up to 35° were reached leading to plasticity spreading across the cross-section. Firstly, the test results were compared against the elastic theory, including theoretical evaluations of the initial stiffness. Secondly, the ultimate capacities were compared to elastic and plastic verifications, showing the extent to which the current design rules are overconservative.

Numerical study of the vibrational absorption considering the periodic foundation effect in a small structure

The growth of urban areas has led buildings to come closer and closer to road traffic routes, exposing civil buildings to traffic vibrations, causing discomfort for users and damage to structures. Although there are numerical studies on traffic vibrations, effective vibrational isolation techniques are little explored in this research. A promising approach is the use of periodic structures. Although used in several areas of engineering, periodic structures still have limited application in civil engineering, especially to isolate vibrations caused by vehicles rolling on pavement in small buildings. In this context, this research developed three numerical finite element models for a small structure, which represent residential and/or commercial buildings with a number of floors equal to or less than three, in reinforced concrete. The first model involved a periodic block-type structure foundation, while the two comparative models included periodic raft-type foundations and block-type concrete foundations. The objective was to analyze the vibrational absorption of different foundations for forced vibrations arising from road traffic in the 1-50Hz range. In order to compare them and observe how beneficial the use of periodic foundation is, in the context of the study. The methodology used consisted of creating structural models using finite elements, applying boundary conditions to couple the foundation layers and the structure, establishing continuity. The study looked for modal responses, and in the frequency domain, resulting from excitation in the foundation, using the Ansys® software (2023) for all simulations. The results revealed that periodic foundations are capable of reducing amplitude peaks at frequencies above 30 Hz, which is beneficial for attenuating vibrations in this range. With an appropriate design, adjusting the geometric and physical parameters of the materials, it is possible to obtain effective vibrational isolation for structures, minimizing vibrations arising from ground waves in buildings. This suggests that the use of periodic structures would be promising in isolating vibrations caused by traffic in small structures.

Vibration analysis of porous orthotropic cylindrical panels resting on elastic foundations based on shear deformation theory

Cylindrical panels are one of the most essential structural members of engineering structures, with mechanical, civil, aeronautical, and marine engineering applications. They are subjected to a wide range of vibrational loads. This article presents a novel higher-order porosity distribution and a free vibration analysis for porous orthotropic cylindrical panels resting on elastic foundations under higher-order shear deformation theory. It is assumed that cylindrical panels are composed of porous materials with uniformly and non-uniformly distributed pores. The porous panels' material properties are distributed in the thickness direction using specific functions. The equations of motion are derived using Hamilton's principle based on trigonometrical shear deformation theory and solved by performing the Galerkin solution procedure with simply supported edge conditions. The accuracy of the obtained natural frequency equation is confirmed by comparing the results to those of previously published in literature. Under comprehensive parametric studies, the influence of porosity coefficient, porosity distribution patterns, radius-to-curve length ratio, orthotropy, and stiffness of elastic foundation parameters on the free vibration response of porous orthotropic cylindrical panels are discussed in detail.

Effect of alkali activated limestone-silica fume blended precursor on performance enhancement of recycled aggregate concrete

The utilization of Recycled Aggregates (RA) from Construction and Demolition (C&D) waste, has been reported to be an efficient way of dealing with the environmental issues encountered by our planet nowadays. However, due to the poor quality of RA, its incorporation in high – grade civil engineering applications been limited. It is essential that adequate process of treatment methods be incorporated into the production of RA to enhance its properties and optimize its use. This study is carried out to determine the effects of an alkaline NaOH activated by limestone powder (LSP) and silica fume (SF) to improve the properties of various concrete mixes produced with either recycled concrete aggregate (RCA), or recycled cement block aggregate (CBA). Fifteen mixes were designed to examine the effects of different parameters, RA replacement levels, various w/c ratios and different enhancement methods on the properties of recycled aggregate concrete (RAC). The study examined the effects of the proposed enhancement method on the physical characteristics of RCA and CBA. Compressive strength, splitting tensile strength, flexural strength, pull-out, and water absorption of the different concrete mixes were measured to determine the effectiveness of the enhancement method proposed. The enhanced RAC produced by CBA and RCA showed an increased 28-day compressive strength at 0.35 w/c ratio of up to 51 MPa and 44 MPa, respectively, suitable for structural applications. The flexural strength, tensile splitting strength, and bonding strength values at 0.35 w/c ratio of the enhanced RAC produced with treated CBA were 28%, 6%, and 8% higher than that of the RAC produced with treated CBA. Whereas, the flexural strength, tensile strength, and bonding strength of the enhanced RAC produced with treated RCA were 1%, 3%, and 5% higher compared to the RAC produced with treated RCA. The improved mechanical performance of the enhanced RAC produced by CBA or RCA was attributed to the effects of the geopolymer solution treatment in filling and sealing the voids and gaps on the CBA and RCA surface, leading to a better packed structure, reducing the water absorption, and improving the aggregate impact value. The treatment technique proposed can be a powerful tool for promoting the use of RA in the construction industry and expanding its application.

Concrete spalling damage detection and seismic performance evaluation for RC shear walls via 3D reconstruction technique and numerical model updating

Current three-dimensional (3D) reconstruction technique-assisted damage detection research focuses on identifying, classifying, and locating surface damage on concrete components, challenging to quantify the effect of the identified damage on structural capacity. This paper attempts to present a novel method based on the 3D reconstruction technique and numerical model updating to detect concrete spalling damage and evaluate the adverse effects of the detected damage on the seismic performance of reinforced concrete (RC) shear wall components. Through a new concept of information transition point matrix, the mapping relationship between the defective information concealed in the reconstructed 3D point cloud model of the inspected wall and the performance variation of its corresponding finite element model is established. Experimental results demonstrate that the newly proposed method can successfully locate the concrete spalling damage and quantify the bearing capacity variation of the inspected specimen, which has excellent potential for future applications in civil engineering.

Long-term performance of concrete reinforced with scrap tire steel fibers in hybrid and non-hybrid forms: Experimental behavior and practical applications

This study examines the potential impact of scrap tire steel fibers (SSFs) on concrete properties, focusing on long-term performance. The reuse of discarded tires in construction addresses the environmental challenge of tire disposal. While previous research has explored SSFs in concrete, long-term properties and practical implementation pathways of SSF-reinforced concrete are lacking. To address these gaps, this study assesses the influence of locally available SSFs from Bratislava, Slovakia, on concrete properties, specifically targeting the 120-day hardened properties. Locally sourced C20/25 concrete is used, incorporating SSFs in non-hybrid (single type of fibers) and hybrid forms (30% industrial hook end steel fibers “ISF”). SSF dosages range from 0.3% to 1.75% for non-hybrid fibers and 0.50% to 0.70% for hybrid fibers. Experimental properties, including elastic modulus (EM), compressive strength (CS), tensile splitting strength (SS), flexure strength (FS), residual flexure strength (RFS), linear shrinkage (LS), and water absorption (WA), are evaluated. The toughness and energy absorption capacity are demonstrated for SS and FS. The results indicate that the inclusion of SSFs enhances the EM and SS of SSF-reinforced concrete (SSFRC). Additionally, SSFRC exhibits reduced linear shrinkage compared to concrete without SSFs. Notably, the hybrid fiber concrete (HSFRC) shows superior performance, outperforming both ISF concrete and SSFRC in enhancing the considered properties. HSFRC exhibits promising potential for replacing ISF concrete in various civil engineering applications. However, further investigation is needed to evaluate the performance of HSFRC under extreme environmental conditions.

Dynamic Properties of Cellular Glass Aggregate as a Lightweight Material

Cellular glass aggregates made from recycled glass are increasingly used in civil engineering and infrastructure applications. However, as this material is relatively new and innovative, it's necessary to obtain a complete mechanical characterization for its usage in the civil engineering field. In this article, the dynamic properties of cellular glass aggregate are investigated with the aid of a large‐scale triaxial apparatus (300 mm diameter and 600 mm height) under cyclic loading. The experimental procedure for building the samples is presented with a brief description of the test setup. A series of cyclic triaxial tests are performed to characterize and evaluate the dynamic properties of the material, which are of interest in the seismic approach (Young's modulus and damping ratio).

Effect of non‐local modified couple stress theory on the responses of axially moving thermoelastic nano‐beams

AbstractThe present study examines the lateral thermal vibrations of a nanobeam subjected to an axial motion while being influenced by a sinusoidal thermal load. The partial differential equation describing the system was obtained using the extended Hamiltonian principle. Also considered were the Euler‐Bernoulli (EB) beam, the nonlocal couple stress theory, and Eringen's nonlocal elasticity model. This type of axially moving beam has multiple applications in design, including industrial, civil, structural, chemical, and computer engineering. The Laplace transform technique is utilized to translate partial differential equations into a thermoelastic differential equation of the sixth order. This study investigates the impact of nanobeam size and velocity on thermo‐mechanical characteristics. To explore the impacts of axial velocity, pulse width, nonlocal index, material length scale coefficient, and phase lag coefficients on the examined studied fields, such as lateral vibration and temperature change for the moving nanobeam are calculated. The specified factors were discovered to impact the flexibility and dynamic response of the nanobeam substantially.