Oveys Ghodousian

55387355000

Publications - 10

Slant shear tests and fuzzy logic integration for evaluating shear bond strength in SCC and FRSCC repair applications

Amin Ghodousian Oveys Ghodousian M. Movahedi Rad Vahid Shafaie Mahdi Homayounfar

Publication Name: Case Studies in Construction Materials

Publication Date: 2025-07-01

Volume: 22

Issue: Unknown

Page Range: Unknown

Description:

This study examines the interfacial bond characteristics of twenty mix proportions, comprising ten self-compacting concrete (SCC) and ten fiber-reinforced self-compacting concrete (FRSCC) formulations, the latter enhanced with 0.1 % polypropylene fibers for repair applications. Initially, experiments such as slump flow, 28-day compressive strength, and tensile strength tests were conducted to evaluate the mechanical properties of the repair layers intended for use in slant shear tests. The primary focus of the research then shifted to determining shear bond strength (SBS) and calculating interfacial cohesion and friction angles using slant shear tests across various inclination angles on these mix proportions applied over a normal vibrated concrete (NVC) substrate. Notably, FRSCC mixtures with 10 % microsilica exhibited notable enhancements, showing increased cohesion of 8.28 MPa and a tensile strength increase of 24.50 % compared to their SCC counterparts. Additionally, a general trend was observed where FRSCC mixtures demonstrated higher cohesion values compared to SCC, underscoring the effectiveness of fiber reinforcement. Furthermore, the research introduces a novel predictive model employing a fuzzy system with a generalized Mamdani's interference engine and Hamacher family of t-norms to accurately predict the SBS, achieving a predictive accuracy with an R2 value up to 0.94. Employing the fuzzy model, characterized by its high predictive accuracy, can significantly reduce the frequency of experimental tests required in the field, thereby lowering construction testing costs and enhancing repair efficiency. These findings not only advance our understanding of SCC and FRSCC behaviors in repair scenarios but also contribute significantly to the development of more reliable and sustainable construction practices by improving the precision of SBS predictions in theoretical modeling and empirical testing.

Open Access: Yes

DOI: 10.1016/j.cscm.2024.e04176

Probabilistic Topology Optimization Framework for Geometrically Nonlinear Structures Considering Load Position Uncertainty and Imperfections

Oveys Ghodousian Hamed Fathnejat M. Movahedi Rad Muayad Habashneh

Publication Name: Mathematics

Publication Date: 2024-12-01

Volume: 12

Issue: 23

Page Range: Unknown

Description:

In this manuscript, a novel approach to topology optimization is proposed which integrates considerations of uncertain load positions, thereby enhancing the reliability-based design within the context of structural engineering. Extending the conventional framework to encompass imperfect geometrically nonlinear analyses, this research discovers the intricate interplay between nonlinearity and uncertainty, shedding light on their combined effects on probabilistic analysis. A key innovation lies in treating load position as a stochastic variable, augmenting the existing parameters, such as volume fraction, material properties, and geometric imperfections, to capture the full spectrum of variability inherent in real-world conditions. To address these uncertainties, normal distributions are adopted for all relevant parameters, leveraging their computational efficacy, simplicity, and ease of implementation, which are particularly crucial in the context of complex optimization algorithms and extensive analyses. The proposed methodology undergoes rigorous validation against benchmark problems, ensuring its efficacy and reliability. Through a series of structural examples, including U-shaped plates, 3D L-shaped beams, and steel I-beams, the implications of considering imperfect geometrically nonlinear analyses within the framework of reliability-based topology optimization are explored, with a specific focus on the probabilistic aspect of load position uncertainty. The findings highlight the significant influence of probabilistic design methodologies on topology optimization, with the defined constraints serving as crucial conditions that govern the optimal topologies and their corresponding stress distributions.

Open Access: Yes

DOI: 10.3390/math12233686

Reinforcement of RC Two-Way Slabs with CFRP Laminates: Plastic Limit Method for Carbon Emissions and Deformation Control

Oveys Ghodousian Marco Domaneschi Zahraa Saleem Sharhan M. Movahedi Rad Raffaele Cucuzza

Publication Name: Buildings

Publication Date: 2024-12-01

Volume: 14

Issue: 12

Page Range: Unknown

Description:

Carbon-fiber-reinforced polymer (CFRP) laminates have gained attention for their potential to reduce carbon emissions in construction. The impact of carbon-fiber-reinforced polymer (CFRP Laminate) on carbon emissions and the influence of elasto-plastic analysis on this technique were studied in this research. This study focuses on how CFRP can affect the environmental footprint of reinforced concrete structures and how elasto-plastic analysis contributes to optimizing this strengthening method. Four flat RC slabs were created to evaluate this technique in strengthening. One slab was used as a reference without strengthening, while the other three were externally strengthened with CFRP. The slabs, which were identical in terms of their overall (length, width, and thickness) as well as their flexural steel reinforcement, were subjected to concentrated patch load until they failed. The strength of two-way RC slabs was analyzed using a concrete plastic damage constitutive model (CDP). Additionally, CFRP strips were applied to the tension surface of existing RC slabs to improve their strength. The load–deflection curves obtained from the simulations closely match the experimental data, demonstrating the validity and accuracy of the model. Strengthening concrete slabs with CFRP sheets reduced central deflection by 17.68% and crack width by 40%, while increasing the cracking load by 97.73% and the ultimate load capacity by 134.02%. However, it also led to a 15.47% increase in CO2 emissions. Also, the numerical results show that increasing the strengthening ratio significantly impacts shear strength and damage percentage.

Open Access: Yes

DOI: 10.3390/buildings14123873

Shear Bond Strength in Stone-Clad Façades: Effect of Polypropylene Fibers, Curing, and Mechanical Anchorage

Amin Ghodousian Hossein Mehdikhani Oveys Ghodousian M. Movahedi Rad Vahid Shafaie Mohammad Gorji

Publication Name: Polymers

Publication Date: 2024-11-01

Volume: 16

Issue: 21

Page Range: Unknown

Description:

This study investigates the shear bond strength between four widely used façade stones—travertine, granite, marble, and crystalline marble—and concrete substrates, with a particular focus on the role of polypropylene fibers in adhesive mortars. The research evaluates the effects of curing duration, fiber dosage, and mechanical anchorage on bond strength. Results demonstrate that Z-type anchorage provided the highest bond strength, followed by butterfly-type and wire tie systems. Extended curing had a significant impact on bond strength for specimens without anchorage, particularly for travertine. The incorporation of polypropylene fibers at 0.2% volume in adhesive mortar yielded the strongest bond, although lower and higher dosages also positively impacted the bonding. Furthermore, the study introduces a novel fuzzy logic model using the Dombi family of t-norms, which outperformed linear regression in predicting bond strength, achieving an R2 of up to 0.9584. This research emphasizes the importance of optimizing fiber dosage in adhesive mortars. It proposes an advanced predictive model that could enhance the design and safety of stone-clad façades, offering valuable insights for future applications in construction materials.

Open Access: Yes

DOI: 10.3390/polym16212975

Plastic Limited Numerical Modelling on Contact Friction Effects of Steel–Concrete Connection for Composite Bridges

Oveys Ghodousian J. Szép Marco Domaneschi M. Movahedi Rad Raffaele Cucuzza Daniel Gosztola

Publication Name: Buildings

Publication Date: 2024-09-01

Volume: 14

Issue: 9

Page Range: Unknown

Description:

This research employs plastic limit analysis to examine load combinations, contact interactions, and friction effects on steel–concrete connections. A nonlinear finite element model was developed using ABAQUS 2021, incorporating the concrete damage plasticity model and contact friction interactions. The model’s validity was confirmed through laboratory experiments. Results indicate that contact elements and friction between the top flange, concrete slab, and studs significantly influence structural behavior. Unlike conventional push-out tests, real deck–slab connections exhibit different load-displacement responses due to the self-weight and additional loads, such as vehicular traffic. Under horizontal loading, extensive failures with large deformations along the studs occur, while vertically compressive loads lead to failures around the connections.

Open Access: Yes

DOI: 10.3390/buildings14092898

Integrating push-out test validation and fuzzy logic for bond strength study of fiber-reinforced self-compacting concrete

Amin Ghodousian Oveys Ghodousian M. Movahedi Rad Raffaele Cucuzza Vahid Shafaie

Publication Name: Construction and Building Materials

Publication Date: 2024-04-26

Volume: 425

Issue: Unknown

Page Range: Unknown

Description:

This study offers a comprehensive analysis of Fiber-Reinforced Self-Compacting Concrete (FRSCC) with a focus on shear bond strength influenced by specific compositions of microsilica, zeolite, slag, and polypropylene fibers. Twenty distinct FRSCC mixes underwent extensive testing, including 28-day compressive strength, tensile strength assessments, and push-out and slant shear tests. A significant outcome is the strong correlation between the push-out and slant shear test results, exemplified by an R² value of 0.88, confirming the push-out test as a viable and practical alternative for bond strength assessment. Experimentally, fibers were found to enhance tensile strength, with the inclusion of 15% microsilica and slag further amplifying this effect, highlighting the critical role of precise pozzolan selection in achieving optimal mechanical performance and workability in FRSCC. Furthermore, the study introduces a fuzzy logic system for predicting shear bond strength, achieving high predictive accuracy with R² values reaching up to 0.96, depending on the t-norms utilized. This research not only validates the push-out test as a reliable method for evaluating shear bond strength in FRSCC but also demonstrates the efficacy of the fuzzy logic approach, representing a groundbreaking contribution in both computational analysis and practical methodology for concrete structural integrity.

Open Access: Yes

DOI: 10.1016/j.conbuildmat.2024.136062

Fuzzy Logic and Push-Out Test Innovations for Fiber-Reinforced Self-compacting Concrete Assessment

Oveys Ghodousian M. Movahedi Rad Vahid Shafaie Géza Herczeg

Publication Name: Fib Symposium

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: 855-862

Description:

This research addresses the deterioration of concrete infrastructures, emphasizing the efficacy of Fiber-Reinforced Self-Compacting Concrete (FRSCC) in repair applications. The study investigates the bond strengths between new and existing concrete layers, employing both experimental and numerical methods to evaluate traditional and innovative testing approaches, including slant shear and push-out tests. Results demonstrate that FRSCC, enhanced with polypropylene fibers, significantly improves structural resilience and mechanical properties. The introduction of fuzzy logic models further refines the prediction of bond strengths, offering a robust framework for future concrete technology advancements.

Open Access: Yes

DOI: DOI not available

Non-Linear Time History and Pushover analysis of a Steel Silo Behavior

Oveys Ghodousian Farhood Shahidi Farhad Shahidi M. Movahedi Rad Vahid Shafaie

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 334-341

Description:

Earthquakes, among the most destructive natural hazards, result in substantial economic and demographic losses. An effective strategy to mitigate future structural damage involves investigating past collapses. Numerical modeling proves instrumental in analyzing and identifying deficiencies in collapsed structures. This study numerically evaluates a steel silo damaged during the 2011 Van earthquake. Employing non-linear time history and pushover analyses, the research assesses the silo's performance. Findings highlight inadequate welding dimensions and incomplete fusion with the base metal in fillet welds between columns and the silo tank as primary causes of collapse. Numerical simulations with varied column removal scenarios underscore the importance of robust silo tank-column connections in reducing earthquake-induced damage.

Open Access: Yes

DOI: 10.3233/ATDE240564

Study of Bonding between Façade Stones and Substrates with and without Anchorage Using Shear-Splitting Test—Case Study: Travertine, Granite, and Marble

Amin Ghodousian Oveys Ghodousian M. Movahedi Rad Vahid Shafaie Sina Hajiloo

Publication Name: Buildings

Publication Date: 2023-05-01

Volume: 13

Issue: 5

Page Range: Unknown

Description:

This paper presents an investigation into the bond strength of three common façade stones, namely, travertine, granite, and marble, to a concrete substrate using a shear-splitting test. The effects of anchorage, the number of curing days, and the presence of an anti-freezing agent in cement–sand mortar on bond strength were studied. The results show that the number of curing days had a significant impact on the bond strength between the stones and the substrates. The presence of an anti-freezing agent and accelerator increased bonding during the initial days, but this effect gradually decreased. The use of anchorage had a positive effect on the bond strength, particularly with fewer curing days. Granite had the lowest bond strength when no anchorage was used due to its low permeability. Based on the findings, a novel fuzzy logic approach was proposed to predict the bond strength. This study provides valuable insights into improving the bonding of façade stones to substrates and can aid in the safe and efficient use of these materials in construction.

Open Access: Yes

DOI: 10.3390/buildings13051229

Interfacial bond strength of coloured SCC repair layers: an experimental and optimisation study

Amin Ghodousian Oveys Ghodousian Vahid Shafaie Reyes Garcia

Publication Name: Journal of Structural Integrity and Maintenance

Publication Date: 2023-01-01

Volume: 8

Issue: 3

Page Range: 140-149

Description:

This study investigates experimentally and analytically the interfacial bond strength of coloured SCC repair layers. Ten SCC mixes with 5%, 10% and 15% of blue, green or red pigments were produced to examine their fresh properties. Subsequently, 60 coloured SCC specimens were tested to assess interfacial bond strength using pull-off and push-out tests. The results confirm that pigments reduce the mechanical properties of SCC and its bond strength to concrete substrates, with red pigment reducing (by up to 41%) interfacial bond strength. It is shown that the push-out test is effective to determine the interfacial shear bond strength between the SCC repair layers and substrates. A GNNC-Modified PSO algorithm is proposed to calculate accurately (R2 = 0.95) the interfacial bond strength of coloured SCC repair layers. This study contributes towards developing more effective test methods and more accurate models to calculate interfacial bond strength of the SCC repair layers used in this study.

Open Access: Yes

DOI: 10.1080/24705314.2023.2170620