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Jwaida, Z., Dulaimi, A., Bahrami, A., Mydin, M. A., Özkılıç, Y. O., Putra Jaya, R. & Wang, Y. (2024). Analytical review on potential use of waste engine oil in asphalt and pavement engineering. Case Studies in Construction Materials, 20, Article ID e02930.
Open this publication in new window or tab >>Analytical review on potential use of waste engine oil in asphalt and pavement engineering
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2024 (English)In: Case Studies in Construction Materials, E-ISSN 2214-5095, Vol. 20, article id e02930Article in journal (Refereed) Published
Abstract [en]

This article provides a comprehensive overview of the research utilising waste engine oil (WEO) in asphalt binders for multiple application purposes and the economic and environmental implications. It covers the various types and sources of WEO for information on their characteristics and the process of preparing WEO-asphalt binders. The study collects the effects of WEO in different applications, including asphalt modification, aged asphalt rejuvenation, self-healing asphalt agents, and WEO composites. It also discusses works on the economic and environmental appraisal associated with a wide WEO utilisation. WEO exhibits both positive and negative influences on asphalt properties. Generally, it improves the performance of asphalt at low temperatures, specifically in terms of reducing issues like thermal cracking and enhancing fatigue resistance. However, it may have a negative impact on the performance of modified asphalt binders at high temperatures. WEO, due to its high concentration of light components, improves the overall performance of aged asphalt. The integration of WEO and reclaimed asphalt binders can enhance the crack resistance, which however highly relies on the added WEO quantity. Future research should be prioritised to understand the comprehensive impact of WEO on reclaimed asphalt binders for the compatibility between the rejuvenator compound and reclaimed aged asphalt, and the effect of WEO on the durability of modified asphalt mixes. In addition, field investigations and analyses are required for a bigger, inclusive, and more detailed picture of the economic and environmental impacts.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
asphalt binder, asphalt pavement, performance improvement, sustainable recycling, waste engine oil.
National Category
Civil Engineering
Identifiers
urn:nbn:se:hig:diva-43791 (URN)10.1016/j.cscm.2024.e02930 (DOI)
Available from: 2024-02-12 Created: 2024-02-12 Last updated: 2024-02-15Bibliographically approved
Sharma, U., Gupta, N., Bahrami, A., Onuralp Özkılıç, Y., Verma, M., Berwal, P., . . . Islam, S. (2024). Behavior of Fibers in Geopolymer Concrete: A Comprehensive Review. Buildings, 14(1), Article ID 136.
Open this publication in new window or tab >>Behavior of Fibers in Geopolymer Concrete: A Comprehensive Review
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2024 (English)In: Buildings, E-ISSN 2075-5309, Vol. 14, no 1, article id 136Article in journal (Refereed) Published
Abstract [en]

Over the last decades, cement has been observed to be the most adaptive material for global development in the construction industry. The use of ordinary concrete primarily requires the addition of cement. According to the record, there has been an increase in the direct carbon footprint during cement production. The International Energy Agency, IEA, is working toward net zero emissions by 2050. To achieve this target, there should be a decline in the clinker-to-cement ratio. Also, the deployment of innovative technologies is required in the production of cement. The use of alternative binding materials can be an easy solution. There are several options for a substitute to cement as a binding agent, which are available commercially. Non-crystalline alkali-aluminosilicate geopolymers have gained the attention of researchers over time. Geopolymer concrete uses byproduct waste to reduce direct carbon dioxide emissions during production. Despite being this advantageous, its utilization is still limited as it shows the quasi-brittle behavior. Using different fibers has been started to overcome this weakness. This article emphasizes and reviews various mechanical properties of fiber-reinforced geopolymer concrete, focusing on its development and implementation in a wide range of applications. This study concludes that the use of fiber-reinforced geopolymer concrete should be commercialized after the establishment of proper standards for manufacturing.

Place, publisher, year, edition, pages
MDPI, 2024
Keywords
geopolymer concrete; fiber-reinforced concrete; mechanical behavior; microstructural analysis; compressive strength; flexural strength
National Category
Civil Engineering
Identifiers
urn:nbn:se:hig:diva-43515 (URN)10.3390/buildings14010136 (DOI)001149406300001 ()2-s2.0-85183356847 (Scopus ID)
Available from: 2024-01-04 Created: 2024-01-04 Last updated: 2024-02-09Bibliographically approved
Hakeem, I. Y., Özkılıç, Y. O., Bahrami, A., Aksoylu, C., Madenci, E., Asyraf, M. R., . . . Fayed, S. (2024). Crashworthiness performance of filament wound GFRP composite pipes depending on winding angle and number of layers. Case Studies in Construction Materials, 20, Article ID e02683.
Open this publication in new window or tab >>Crashworthiness performance of filament wound GFRP composite pipes depending on winding angle and number of layers
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2024 (English)In: Case Studies in Construction Materials, E-ISSN 2214-5095, Vol. 20, article id e02683Article in journal (Refereed) Published
Abstract [en]

The main goal of this study is to increase the crashworthiness performance of tubular composite to absorb more energy by optimizing the orientation of its fibers. The crashworthiness performance of glass fiber-reinforced polymer (GFRP) composite pipes manufactured using the filament winding process is investigated in detail. The effects of fiber orientation and thickness of tube wall on energy absorption capabilities were investigated through quasi-static compression tests. The composite pipes were produced with 1200 tex E-glass fibers and Epikote 828 resin as the matrix material. The winding angles of ±30°, ±45°, ±55°, ±75°, and ±90° were examined, and the number of winding layers ranged from 1 to 3 were also examined. Quasi-static axial compressive loading was applied to 15 specimens using a hydraulic actuator. The results revealed that single-layered samples experienced buckling damage at low load levels, while an increase in the number of layers led to higher load-carrying capacity and different types of damage. Furthermore, as the number of layers increased, the load-carrying capacity and energy absorption capacity significantly improved. Progressive failure was observed in [±90°] wound samples for all layer configurations, with [±90°]3 exhibiting the highest performance in terms of load-carrying capacity and energy absorption. The damaged shapes indicated a combination of fiber separation, buckling, diagonal shearing failure, and crushing in the upper and lower heads.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
crashworthiness performance, tubular composite, glass fiber-reinforced polymer, filament winding process, buckling damage, load-carrying capacity, energy absorption capacity
National Category
Civil Engineering
Identifiers
urn:nbn:se:hig:diva-43340 (URN)10.1016/j.cscm.2023.e02683 (DOI)001132030100001 ()2-s2.0-85178361657 (Scopus ID)
Available from: 2023-11-27 Created: 2023-11-27 Last updated: 2024-01-12Bibliographically approved
Nagaraju, T. V. & Bahrami, A. (2024). Development of Sustainable Concrete Using Treated Bamboo Reinforcement. In: Alireza Bahrami (Ed.), Sustainable Structures and Buildings: (pp. 39-49). Springer
Open this publication in new window or tab >>Development of Sustainable Concrete Using Treated Bamboo Reinforcement
2024 (English)In: Sustainable Structures and Buildings / [ed] Alireza Bahrami, Springer , 2024, p. 39-49Chapter in book (Refereed)
Abstract [en]

Due to the expanding global population and rising per capita consumption, there has been an increase in the demand for environmentally friendly building materials in recent years. Moreover, the quest for steel and cement alternatives has become more crucial. Any substitute materials must be reasonably priced, fast growing, equivalent in the strength and characteristics, and environmentally friendly. In the current chapter, first, a tensile strength test was conducted on available bamboo strips to determine their ultimate strength and other engineering characteristics. Then, bitumen and epoxy resin were applied to bamboo to investigate the effects of two alternative adhesives on the bond resistance offered with the contact of the bamboo structural specimen. Moreover, experiments were performed on steel and bamboo-reinforced concrete beams to further study the load-carrying capacity, deflection, ductility, stiffness, and energy absorption. In addition, beams were subjected to a two-point stress test to examine how they respond to bending. These experiments indicated that when treated properly, bamboo can replace steel as structural reinforcement in concrete beams.

Place, publisher, year, edition, pages
Springer, 2024
Keywords
Sustainable concrete, Epoxy resin, Energy absorption, Load-carrying capacity, Deflection, Ductility, Stiffness, Treated bamboo reinforcement
National Category
Civil Engineering
Identifiers
urn:nbn:se:hig:diva-43558 (URN)10.1007/978-3-031-46688-5_3 (DOI)978-3-031-46687-8 (ISBN)978-3-031-46688-5 (ISBN)
Available from: 2024-01-09 Created: 2024-01-09 Last updated: 2024-01-09Bibliographically approved
Shakouri Mahmoudabadi, N., Bahrami, A., Saghir, S., Ahmad, A., Iqbal, M., Elchalakani, M. & Özkılıç, Y. O. (2024). Effects of eccentric loading on performance of concrete columns reinforced with glass fiber‑reinforced polymer bars. Scientific Reports, 14, Article ID 1890.
Open this publication in new window or tab >>Effects of eccentric loading on performance of concrete columns reinforced with glass fiber‑reinforced polymer bars
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2024 (English)In: Scientific Reports, E-ISSN 2045-2322, Vol. 14, article id 1890Article in journal (Refereed) Published
Abstract [en]

Glass fiber-reinforced polymer (GFRP) reinforcements are superior to traditional steel bars in concrete structures, particularly in vertical elements like columns, and offer significant advantages over conventional steel bars when subjected to axial and eccentric loadings. However, there is limited experimental and numerical research on the behavior of GFRP-reinforced concrete (RC) columns under eccentric loading having different spacing of stirrups. In this study, six specimens were cast under three different values of eccentricities (25 mm, 50 mm, and 75 mm) with two groups of stirrups spacing (50 mm and 100 mm). The experimental results showed that by increasing the eccentricity value, there was a reduction in the load-carrying capacity of the specimens. The finite element ABAQUS software was used for the numerical investigation of this study. The results from the finite element analysis (FEA) were close to the experimental results and within the acceptable range. The maximum difference between the experimental and FEA results was 3.61% for the axial load and 12.06% for the deformation.

Place, publisher, year, edition, pages
Springer, 2024
National Category
Civil Engineering
Identifiers
urn:nbn:se:hig:diva-43641 (URN)10.1038/s41598-023-47609-4 (DOI)001148428500016 ()38253684 (PubMedID)2-s2.0-85182817455 (Scopus ID)
Available from: 2024-01-22 Created: 2024-01-22 Last updated: 2024-02-22Bibliographically approved
Mydin, M. A., Jagadesh, P., Bahrami, A., Dulaimi, A., Özkılıç, Y. O. & Omar, R. (2024). Enhanced fresh and hardened properties of foamed concrete modified with nano-silica. Heliyon, 10(4), Article ID e25858.
Open this publication in new window or tab >>Enhanced fresh and hardened properties of foamed concrete modified with nano-silica
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2024 (English)In: Heliyon, E-ISSN 2405-8440, Vol. 10, no 4, article id e25858Article in journal (Refereed) Published
Abstract [en]

Nowadays, the application of nanotechnology has gained increased attention in the concrete technology field. Several applications of concrete require light weight; one such concrete used is foamed concrete (FC), which has more voids in the microstructure. In this study, nano-silica (NS) was utilized, which exhibits a pozzolanic nature, and it reacts with other pozzolanic compositions (like lime, alumina, etc.) to form hydrated compounds in concrete. Apart from these hydrated compounds, NS acts as a filler material and enhances properties of concrete such as the fresh and hardened properties. This research examines the fresh, hardened, and microstructural properties of FC blended with NS. The ratio of binder and filler used in this research is 1:1.5, with a water-to-binder ratio of 0.45 and a density of 880 kg/m3. A total of six different weight fractions of NS were added to FC mixes, namely 0%, 1%, 2%, 3%, 4%, and 5%. Properties assessed for FC blended with NS were the slump, bulk density, strength parameters (flexural, splitting tensile, and compressive strengths), morphological analysis, water absorption, and porosity. It was concluded from this study that the optimum NS utilized to improve the properties was 3%. Apart from this, the relationship between the mechanical properties and NS dosages was developed. The correlations between the compressive strength and other properties were analyzed, and relationships were developed based on the best statistical approach. This study helps academicians, researchers, and industrialists enhance the properties of FC blended with NS and their relationships to predict concrete properties from other properties.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
foamed concrete; nano-silica; pozzolanic compositions; intrinsic air permeability; compressive strength; SEM analysis; chloride penetration
National Category
Civil Engineering
Identifiers
urn:nbn:se:hig:diva-43803 (URN)10.1016/j.heliyon.2024.e25858 (DOI)
Available from: 2024-02-14 Created: 2024-02-14 Last updated: 2024-02-27Bibliographically approved
Ali, L., Isleem, H. F., Bahrami, A., Jha, I., Zou, G., Kumar, R., . . . Jahami, A. (2024). Integrated behavioural analysis of FRP-confined circular columns using FEM and machine learning. Composites Part C: Open Access, 13, Article ID 100444.
Open this publication in new window or tab >>Integrated behavioural analysis of FRP-confined circular columns using FEM and machine learning
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2024 (English)In: Composites Part C: Open Access, ISSN 2666-6820, Vol. 13, article id 100444Article in journal (Refereed) Published
Abstract [en]

This study investigates the structural behaviour of double-skin columns, introducing novel double-skin double filled tubular (DSDFT) columns, which utilise double steel tubes and concrete to enhance the load-carrying capacity and ductility beyond conventional double-skin hollow tubular (DSHT) columns, employing a combination of finite element model (FEM) and machine learning (ML) techniques. A total of 48 columns (DSHT+DSDFT) were created to examine the impact of various parameters, such as double steel tube configurations, thickness of fibre-reinforced polymer (FRP) layer, type of FRP material, and steel tube diameter, on the load-carrying capacity and ductility of the columns. The results were validated against the experimental findings to ensure their accuracy. Key findings highlight the advantages of the DSDFT configuration. Compared to the DSHT columns, the DSDFT columns exhibited remarkable 19.54 % to 101.21 % increases in the load-carrying capacity, demonstrating improved ductility and load-bearing capabilities. Thicker FRP layers enhanced the load-carrying capacity up to 15 %, however at the expense of the reduced axial strain. It was also observed that glass FRP wrapping displayed 25 % superior ultimate axial strain than aramid FRP wrapping. Four different ML models were assessed to predict the axial load-carrying capacity of the columns, with long short-term memory (LSTM) and bidirectional LSTM models emerging as superior choices indicating exceptional predictive capabilities. This interdisciplinary approach offers valuable insights into designing and optimising confined column systems. It sheds light on both double-tube and single-tube configurations, propelling advancements in structural engineering practices for new constructions and retrofitting. Further, it lays out a blueprint for maximising the performance of the confined columns under the axial compression.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
Confined concrete, Double steel tube, Finite element model, FRP reinforcement, Strength enhancement, Machine learning
National Category
Civil Engineering
Identifiers
urn:nbn:se:hig:diva-43845 (URN)10.1016/j.jcomc.2024.100444 (DOI)
Available from: 2024-02-28 Created: 2024-02-28 Last updated: 2024-02-28
Isleem, H. F., Zewudie, B. B., Bahrami, A., Kumar, R., Xingchong, W. & Samui, P. (2024). Parametric investigation of rectangular CFRP-confined concrete columns reinforced by inner elliptical steel tubes using finite element and machine learning models. Heliyon, 10(2), Article ID e23666.
Open this publication in new window or tab >>Parametric investigation of rectangular CFRP-confined concrete columns reinforced by inner elliptical steel tubes using finite element and machine learning models
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2024 (English)In: Heliyon, E-ISSN 2405-8440, Vol. 10, no 2, article id e23666Article in journal (Refereed) Published
Abstract [en]

Nowadays, due to the structural advantages gained by combining three different materials’ properties, columns made of carbon-fiber reinforced polymer (CFRP)-confined concrete with inner steel tube have received researchers’ interest. This article presents the nonlinear finite element analysis and multiple machine learning (ML) model-based study on the behavior of round corner rectangular CFRP-confined concrete short columns reinforced by the inner high-strength elliptical steel tube under the axial load. The reliability of the proposed nonlinear finite element model was verified against the existing experimental investigations. The effects of the parameters such as the concrete grade, thickness of reinforcing steel tube, cross-sectional size of inner steel tube, and thickness of CFRP on the behavior of the columns are comprehended in this study. Furthermore, multiple ML models were proposed to predict the ultimate axial load, ultimate axial strain, and lateral strain of the test specimens. The reliability of the proposed ML models was evaluated by six distinct performance metrics. From the parametric investigation, it was found that concrete with lower compressive strength gained more strength enhancement because of confinement between CFRP and the inner steel tube than high-strength concrete relative to its unconfined compressive strength. The proposed ML models of extreme gradient boosting and random forest provided the best-fit results than the artificial neural network and Gaussian process regression models in predicting the axial load and axial and lateral strains of the columns.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
Confined concrete, Steel tube, Dilation angle, Lateral strain, Strength enhancement, Machine learning
National Category
Civil Engineering
Identifiers
urn:nbn:se:hig:diva-43566 (URN)10.1016/j.heliyon.2023.e23666 (DOI)2-s2.0-85182367662 (Scopus ID)
Available from: 2024-01-11 Created: 2024-01-11 Last updated: 2024-01-22Bibliographically approved
Honghao, R., Bahrami, A., Cehlin, M. & Wallhagen, M. (2024). Proposing new adhesive-free timber edge connections for cross-laminated timber panels: A step toward sustainable construction. Case Studies in Construction Materials, 20, Article ID e02975.
Open this publication in new window or tab >>Proposing new adhesive-free timber edge connections for cross-laminated timber panels: A step toward sustainable construction
2024 (English)In: Case Studies in Construction Materials, E-ISSN 2214-5095, Vol. 20, article id e02975Article in journal (Refereed) Published
Abstract [en]

The use of timber as a building material is becoming increasingly popular thanks to its superior environmental performance compared with concrete and steel. However, timber structures rely on solid connections to improve their weak expansibility. Steel connections can be prone to corrosion over time, leading to the decreased structural integrity. Additionally, steel connections require more material and energy to manufacture and install compared with timber connections. This article focuses on the flexural performance of cross-laminated timber (CLT) panels with adhesive-free edge connections under four-point bending tests. First, numerical models of experimentally tested CLT panels were constructed using the finite element (FE) software ABAQUS. Then, these FE models were validated with the comparisons of their results with those of the experimental tests. Afterward, four new adhesive-free edge connections using timber for the CLT panels were developed in this study, helping sustainable construction. Utilizing the designed edge connections of the current study, forty-one parametric studies were numerically conducted on the connected CLT panels to investigate their ultimate loads, strains, displacements, moment capacities, failure modes, and effective stiffness. The factors affecting the edge connections’ load-bearing capacity were also examined and discussed. The study provides helpful insights into the development of CLT as a sustainable construction material with improved adhesive-free edge connections.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
Cross-laminated timber, Adhesive-free edge connections, Load-bearing capacity, Finite element method, Flexural performance, VUSDFLD subroutine
National Category
Civil Engineering
Identifiers
urn:nbn:se:hig:diva-43804 (URN)10.1016/j.cscm.2024.e02975 (DOI)
Available from: 2024-02-14 Created: 2024-02-14 Last updated: 2024-02-26Bibliographically approved
Awoyera, P. O., Akin-Adeniyi, A., Bahrami, A. & Bendezu Romero, L. M. (2024). Structural performance of fire-damaged concrete beams retrofitted using bamboo fiber laminates. Results in Engineering (RINENG), 21, Article ID 101821.
Open this publication in new window or tab >>Structural performance of fire-damaged concrete beams retrofitted using bamboo fiber laminates
2024 (English)In: Results in Engineering (RINENG), ISSN 2590-1230, Vol. 21, article id 101821Article in journal (Refereed) Published
Abstract [en]

Fire-induced damage is a serious threat to the structural integrity of reinforced concrete (RC) beams, necessitating an effective retrofitting strategy to restore and improve their performance. This study investigates the structural performance of fire-damaged RC beams retrofitted with bamboo fiber laminates. A comprehensive analysis was performed, incorporating degradation rules to quantify the effect of temperature on both the load-carrying capacity and ultimate deflection of the RC beams. Eight conventionally designed and reinforced RC beams were tested, with two serving as controls. The remaining six beams were tested in pairs at three different temperatures (400 C, 600 C, and 800 C) for 2-h exposure, with one beam featuring the bamboo fiber laminates in each pair. The bamboo fiber laminates enhanced the load-carrying capacity and deflection of the fire-damaged beams when subjected to incremental loading until failure. The deflection was improved by 48.78% at 400 C, restoring the load-carrying capacity to control levels. The load-carrying capacity was increased by 29.5% at 600 C, while the deflection was restored by 39.37%. The load-carrying capacity was enhanced by 37% at 800 C, while the deflection was improved by 4.83%. According to the findings, bamboo fiber laminate is a viable alternative to synthetic fibers for retrofitting fire-damaged beams.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
Structural retrofitting, Bamboo fiber, Green material, Fiber-reinforced polymer, Fire-damaged beam, Deflection
National Category
Civil Engineering
Identifiers
urn:nbn:se:hig:diva-43755 (URN)10.1016/j.rineng.2024.101821 (DOI)2-s2.0-85184492426 (Scopus ID)
Available from: 2024-02-05 Created: 2024-02-05 Last updated: 2024-02-19Bibliographically approved
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