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Impact resistance, water transport properties and sodium sulphate attack are important criteria to determine the performance of concrete incorporating mixed types of recycled plastic waste. Nine mixes were designed with different combinations of the three plastic types; Polyethylene terephthalate (PET), High density polyethylene (HDPE) and Polypropylene (PP). The plastic partially substituted the coarse aggregate (by volume) at various replacement ratios; 10%, 15%, 20% and 30%. The impact resistance and water transport properties were evaluated for nine mixes while sodium sulphate attack test was performed for three mixes. The results showed that the addition of mixed recycled plastic in concrete improved the impact resistance. The highest impact resistance improvement was achieved by R8 (PET + HDPE + PP) at 30% replacement which was 4.5 times better than the control mix. Water absorption results indicated a slight increase in all plastic mixes while contradictory results were observed for sorptivity test. Analysis of sodium sulphate attack results showed that incorporating 30% mixed plastic reduced the sodium sulphate resistance slightly due to the collective effect of plastic entrapping of sulphate ions after 80 cycles. This study has shown some positive results relating to the impact performance of Mixed Recycled Plastic Concrete (MRPC) which enhances its use in a sustainable way.
Mahmoud Abu-Saleem; Yan Zhuge; Reza Hassanli; Mark Ellis; Mizanur Rahman; Peter Levett. Impact Resistance and Sodium Sulphate Attack Testing of Concrete Incorporating Mixed Types of Recycled Plastic Waste. Sustainability 2021, 13, 9521 .
AMA StyleMahmoud Abu-Saleem, Yan Zhuge, Reza Hassanli, Mark Ellis, Mizanur Rahman, Peter Levett. Impact Resistance and Sodium Sulphate Attack Testing of Concrete Incorporating Mixed Types of Recycled Plastic Waste. Sustainability. 2021; 13 (17):9521.
Chicago/Turabian StyleMahmoud Abu-Saleem; Yan Zhuge; Reza Hassanli; Mark Ellis; Mizanur Rahman; Peter Levett. 2021. "Impact Resistance and Sodium Sulphate Attack Testing of Concrete Incorporating Mixed Types of Recycled Plastic Waste." Sustainability 13, no. 17: 9521.
This paper presents the results of an experimental study on a full-scale precast concrete frame reinforced with glass fibre reinforced polymer (GFRP) bars that was tested to failure under lateral cyclic loading. Within the frame four different pocket connections are tested that will lead to accelerated construction. Traditionally, a pocket connection is comprised of a column that is extended into a recessed portion of the connecting beam and the pocket is filled with grout to create a moment-resisting connection. In order to accelerate the construction process, quicker setting epoxy resin was used in place of grout. The results show that while the epoxy resin could significantly accelerate and simplify the construction procedure due to its workability in addition to its high early strength and non-shrinkable properties, its thickness and low modulus of elasticity significantly affected the performance of the pocket joint. The test frame showed a flag-shaped hysteretic behaviour with narrow loops and small residual displacement thus illustrating desirable frame self-centring behaviour. This self-centring behaviour was due to rocking of the column in the pocket connection. The frame displaced with a large displacement ductility of approximately 7.0, however, the level of energy dissipation and damping ratio was very low when compared with conventional concrete structures. This experimental study shows that pocket connections can be used for GFRP reinforced precast concrete elements, however, they should be designed carefully to account for the lower stiffness of GFRP reinforcement. Also, to avoid premature failure and achieve a higher capacity of the pocket connections, the material used in the pocket to fill the gap between column and beam is recommended to have higher strength and elastic modulus compared to the surrounding precast concrete.
Reza Hassanli; Thomas Vincent; Allan Manalo; Scott T. Smith; Aliakbar Gholampour; Rebecca Gravina. Large-scale experimental study on pocket connections in GFRP-reinforced precast concrete frames. Structures 2021, 34, 523 -541.
AMA StyleReza Hassanli, Thomas Vincent, Allan Manalo, Scott T. Smith, Aliakbar Gholampour, Rebecca Gravina. Large-scale experimental study on pocket connections in GFRP-reinforced precast concrete frames. Structures. 2021; 34 ():523-541.
Chicago/Turabian StyleReza Hassanli; Thomas Vincent; Allan Manalo; Scott T. Smith; Aliakbar Gholampour; Rebecca Gravina. 2021. "Large-scale experimental study on pocket connections in GFRP-reinforced precast concrete frames." Structures 34, no. : 523-541.
Glass fiber reinforced polymer (GFRP) is an effective alternative reinforcing solution to tackle problems associated with steel corrosion in reinforced concrete structures located in harsh environments. However, there are multiple construction challenges when cast-in-place GFRP reinforced concrete is used. Cast-in-place concrete is both labor and time intensive on account of timely assembly of falsework and formwork as well as pouring and curing of concrete. To avoid such challenges and accelerate the construction process, GFRP reinforced precast concrete elements can be used to avoid corrosion problems, improve the quality of the construction and reduce the associated risk and total cost. While GFRP reinforced precast concrete elements exhibit behavior comparable to those reinforced with steel, research on connections between precast elements is limited. This study aims to investigate the performance of bent cap connections for GFRP precast concrete elements for applications in bridge and jetty structures. An experimental investigation was designed and conducted on a large-scale concrete frame constructed out of GFRP reinforced precast concrete elements with four different types of pocketless connections. The effectiveness of using epoxy resin rather than conventional cement grout to accelerate the construction process was investigated. Also investigated were the effect of pre-stressing, the number of connecting reinforcement elements, and the type of reinforcement (i.e. bars and bolts). The frame was subjected to cyclic lateral loading and was tested in two stages. Results and discussion on the general behavior, failure modes, energy dissipation, damping ratio and ductility were presented. The results of the pocketless test frame were also compared with a similar frame tested previously by the same research group where pocket connections were used to transfer moment between the beam and column members. The results showed that using connecting bars/bolts in pocketless connections outperform the behavior of pocket connections. This study concluded that avoiding pockets and providing the integrity of the beam-column joint through bolt/bar connection can improve the general performance of the beam-column connection compared to connections with pockets. This method also increases the speed of construction and simplifies the manufacturing procedure.
Reza Hassanli; Tom Vincent; Allan Manalo; Scott T. Smith; Aliakbar Gholampour; Rebecca Gravina; Yan Zhuge. Connections in GFRP reinforced precast concrete frames. Composite Structures 2021, 276, 114540 .
AMA StyleReza Hassanli, Tom Vincent, Allan Manalo, Scott T. Smith, Aliakbar Gholampour, Rebecca Gravina, Yan Zhuge. Connections in GFRP reinforced precast concrete frames. Composite Structures. 2021; 276 ():114540.
Chicago/Turabian StyleReza Hassanli; Tom Vincent; Allan Manalo; Scott T. Smith; Aliakbar Gholampour; Rebecca Gravina; Yan Zhuge. 2021. "Connections in GFRP reinforced precast concrete frames." Composite Structures 276, no. : 114540.
Different types of recycled plastic have been used in concrete and most studies have focused on the behaviour of a single type of plastic. However, separating plastic wastes increases the cost and time of processing. To tackle this problem, this research presents an experimental investigation to determine the effect of incorporating different combinations of three types of recycled plastic waste aggregates—Polyethylene terephthalate (PET), High Density Polyethylene (HDPE) and Polypropylene (PP)—at different replacement ratios of coarse aggregate on physical and mechanical properties of concrete. The combinations include two plastic types at 10% and 20% replacement ratios and three plastic types at 15% and 30% replacement ratios. The performance of the plastic concrete was assessed based on various physical and mechanical properties including workability, fresh and dry densities, air content, compressive, indirect tensile and flexural strengths, modulus of elasticity, stress-strain behaviour and ultrasonic pulse velocity. It is found that the workability of Mixed Recycled Plastic Concrete (MRPC) at a low replacement rate is independent of the type of plastic. The minimum reduction in the compressive strength, indirect tensile and modulus of elasticity were achieved by R3 (PET + PP) at 10% replacement, while R5 (HDPE + PP) at 10% replacement achieved the highest flexural strength and ultrasonic pulse velocity values. The findings suggest that the mixed recycled plastics have a good possibility to partially replace coarse aggregates in concrete which will benefit the plastics recycling community and environment. Furthermore, the study will provide guidance to the concrete industry concerning the effect of the implementation of unsorted mixed types of plastic as coarse aggregates in the production of concrete.
Mahmoud Abu-Saleem; Yan Zhuge; Reza Hassanli; Mark Ellis; Mizanur Rahman; Peter Levett. Stress-Strain Behaviour and Mechanical Strengths of Concrete Incorporating Mixed Recycled Plastics. Journal of Composites Science 2021, 5, 146 .
AMA StyleMahmoud Abu-Saleem, Yan Zhuge, Reza Hassanli, Mark Ellis, Mizanur Rahman, Peter Levett. Stress-Strain Behaviour and Mechanical Strengths of Concrete Incorporating Mixed Recycled Plastics. Journal of Composites Science. 2021; 5 (6):146.
Chicago/Turabian StyleMahmoud Abu-Saleem; Yan Zhuge; Reza Hassanli; Mark Ellis; Mizanur Rahman; Peter Levett. 2021. "Stress-Strain Behaviour and Mechanical Strengths of Concrete Incorporating Mixed Recycled Plastics." Journal of Composites Science 5, no. 6: 146.
This paper presents an investigation on the cyclic behavior and design aspects of a hybrid self-centering wall (SW), in terms of the wall’s axial stress and post-tensioning tendons’ prestressing ratios. These key parameters are examined extensively within the context of both force and displacement-based design approaches. Finite element models of SWs are developed and verified against experimental results available from the literature. The numerical model is used to perform a parametric study where the wall’s behavior, including cyclic response, damage severity and pattern, energy dissipation, stiffness degradation, period shift, and residual drift are widely discussed in the context of the aforementioned design approaches. Numerical results indicate that an increase in the axial stress ratio intensifies the extent and severity of the wall’s damage, lateral capacity, residual drift, energy dissipation, and structural seismic demand. Additionally, it is shown that by increasing the tendons’ prestressing ratio, the structural seismic demand is increased, while the wall’s damage, residual drift, and energy dissipation capacity are decreased. Based on this study, the wall’s axial stress ratio and the tendons’ prestressing ratio should be limited to a range of 0.075–0.115 and less than 0.75, respectively, to meet the basic objective performance. Higher objective performance criteria could be maintained with using external energy dissipaters, and adopting a suitable design approach.
Abouzar Jafari; Habib Akbarzadeh Bengar; Reza Hassanli; Maryam Nazari; Roberto Dugnani. The response of self-centering concrete walls under quasi-static loading. Bulletin of Earthquake Engineering 2021, 19, 2893 -2917.
AMA StyleAbouzar Jafari, Habib Akbarzadeh Bengar, Reza Hassanli, Maryam Nazari, Roberto Dugnani. The response of self-centering concrete walls under quasi-static loading. Bulletin of Earthquake Engineering. 2021; 19 (7):2893-2917.
Chicago/Turabian StyleAbouzar Jafari; Habib Akbarzadeh Bengar; Reza Hassanli; Maryam Nazari; Roberto Dugnani. 2021. "The response of self-centering concrete walls under quasi-static loading." Bulletin of Earthquake Engineering 19, no. 7: 2893-2917.
This paper reports on a comprehensive research on the performance of self-centering masonry walls (SMWs). A summary of an experimental study is presented. Finite element (FE) study was performed and verified against experimental results to predict the behaviour of SMWs. Using the verified FE modelling; Phase I of a parametric study was conducted aiming at developing a refined approach to better predict the ultimate capacity of SMWs. Subsequently, an equation was derived to estimate the length of the plastic hinge, which was then incorporated into an analytical method to determine the force–displacement behaviour of SMWs. In the analytical approach, displacement compatibility rather than strain compatibility was considered assuming the rocking mechanism of SMWs. Using experimental results; it was shown that the analytical approach could be used to effectively predict the force–displacement response of SMWs. The verified analytical method was then used to carry out Phase II of the parametric study, resulting in developing a new equation to estimate the depth of neutral axis depth. Using this new equation and plastic hinge expression developed in Phase I of the parametric study, a simplified expression was proposed to determine the flexural capacity of SMWs. Using both laboratory tests and numerical modelling analysis, it was indicated that both of the proposed refined and simplified method could significantly improve the strength prediction of SMWs.
Reza Hassanli. In-plane flexural response of self-centering masonry walls (SMWs). Archives of Civil and Mechanical Engineering 2021, 21, 1 -22.
AMA StyleReza Hassanli. In-plane flexural response of self-centering masonry walls (SMWs). Archives of Civil and Mechanical Engineering. 2021; 21 (2):1-22.
Chicago/Turabian StyleReza Hassanli. 2021. "In-plane flexural response of self-centering masonry walls (SMWs)." Archives of Civil and Mechanical Engineering 21, no. 2: 1-22.
This paper reports on an experimental study on nine Post-tensioned Segmental Retaining Walls (PSRWs). All the walls were post-tensioned and tested under incrementally increasing cyclic loading. Each test wall was constructed using four T-shaped precast concrete blocks, assembled on top of each other with dry joints. The integrity of the system was maintained using post-tensioning (PT). Different levels of PT forces were applied to investigate the effect of it. Different wall-footing interface materials were used including steel plate, concrete and neoprene pad. Conventional concrete and crumb rubberized concrete was used to investigate the effect of concrete properties on the structural behavior of retaining walls. Three walls with confinement (confined with either Carbon Fiber Reinforced Polymer (CFRP), steel reinforcement or steel face plate) were tested. The force–displacement responses, energy dissipation, post-tensioning stresses, gap rotation, lateral stiffness, and normal strains were observed and compared. The results from this study showed that the level of axial stress ratio, eccentricity of pre-stressing as well as the properties of the wall-footing interface material is critical to provide enough lateral strength and stiffness for engineering design of the PSRW. The wall with steel plate on compression face had the largest ultimate strength. The specimen having largest PT force generated largest initial and secant stiffness. Additional reinforcement of the bottom most segment is also required to avoid sudden failure and increase ductility in T-shaped blocks. Lateral stiffness increases in conventional concrete was much higher than rubberized concrete when PT force was increased. None of concrete confinement methods applied (CFRP confinement, steel reinforcement and steel face plate) affected energy dissipation characteristics of the tested walls. Using neoprene as the interface material for wall-footing significantly increased energy dissipation and concrete wall-footing interface showed more energy dissipation in comparison to steel interface material. Stiffness degradation of all walls had similar rate against wall lateral displacement. This paper concluded that the proposed segmental retaining wall system is potentially a practical alternative to accelerate the construction of retaining walls using precast concrete blocks.
Mehdi Javadi; Reza Hassanli; Mizanur Rahman; Rajibul Karim. Experimental study on cyclic behavior of post-tensioned segmental retaining walls (PSRWs). Engineering Structures 2020, 229, 111619 .
AMA StyleMehdi Javadi, Reza Hassanli, Mizanur Rahman, Rajibul Karim. Experimental study on cyclic behavior of post-tensioned segmental retaining walls (PSRWs). Engineering Structures. 2020; 229 ():111619.
Chicago/Turabian StyleMehdi Javadi; Reza Hassanli; Mizanur Rahman; Rajibul Karim. 2020. "Experimental study on cyclic behavior of post-tensioned segmental retaining walls (PSRWs)." Engineering Structures 229, no. : 111619.
This paper presents the results of an experimental study into the behavior of rubberized concrete-filled fiber-reinforced polymer tube (CFFT) columns, where the fiber-reinforced polymer (FRP) confining layer is prestressed by using an expansive agent (EA). The study focuses on utilizing the incompressibility property of rubber in improving the strength properties of crumb rubber concrete (CRC). A total of 27 CFFT columns were tested under axial compression and the effect of rubber content, prestress level, confinement amount and curing condition was studied. Different EAs with cement replacement ratios of 0%, 7.5%, and 15% were used to examine the influence of different levels of hoop prestress on the axial compressive behavior. The influence of amount of confinement was examined with specimens prepared with either one or two layers of CFRP. The influence of the curing condition was also examined by preparing half of the one-layer specimens with steel plates confining the specimens in the axial direction during curing. Finally, both flexible and stiff molds were used to examine the influence of mold stiffness on prestress development during curing. The lateral prestress provided by the expansive agent and FRP confinement was used to mitigate the typical strength reduction associated with CRC. The positive effect of this technique is two-fold. First, the pressure produced by the expansive agent compresses the cement paste and rubber particles together, reducing porosity and increasing interaction and interface friction between the rubber particles and cement paste. Second, rubber is generally considered nearly incompressible, with a Poisson's ratio of approximately 0.5, hence as the rubber is compressed in one direction, it expands significantly in the other directions. Using rubber in unconfined and non-prestressed concrete results in strength reduction; however, the combined effects of FRP-confinement and lateral prestress on CRC can lead to significant increases in the columns' axial stiffness and strength. The stresses and strains developed during curing for the expansive mixes were found to be considerably higher in CRC compared with conventional concrete (CC), indicating that an EA is more effective in developing prestress in rubberized concrete. Moreover, the mold stiffness was found to have a noticeable influence on the compressive strength of concrete. Using stiff molds resulted in unrealistic and unsafe strength evaluation and, hence, should be avoided if expansive concrete is used, or the results should be modified to account for the effect of confinement provided by the stiff molds. It was also observed that the confinement effect in CRC was higher compared with that of CC, which is due to the incompressibility of rubber. Finally, applying confinement plates to the ends of the concrete during curing had insignificant impact on the compressive behavior.
Reza Hassanli; Osama Youssf; Tom Vincent; Julie Mills; Allan Manalo; Rebecca Gravina. Experimental Study on Compressive Behavior of FRP-Confined Expansive Rubberized Concrete. Journal of Composites for Construction 2020, 24, 04020034 .
AMA StyleReza Hassanli, Osama Youssf, Tom Vincent, Julie Mills, Allan Manalo, Rebecca Gravina. Experimental Study on Compressive Behavior of FRP-Confined Expansive Rubberized Concrete. Journal of Composites for Construction. 2020; 24 (4):04020034.
Chicago/Turabian StyleReza Hassanli; Osama Youssf; Tom Vincent; Julie Mills; Allan Manalo; Rebecca Gravina. 2020. "Experimental Study on Compressive Behavior of FRP-Confined Expansive Rubberized Concrete." Journal of Composites for Construction 24, no. 4: 04020034.
Jamal Elmapruk; Mohamed A. ElGawady; Reza Hassanli. Experimental and Analytical Study on the Shear-Strength of Partially Grouted Masonry Walls. Journal of Structural Engineering 2020, 146, 04020147 .
AMA StyleJamal Elmapruk, Mohamed A. ElGawady, Reza Hassanli. Experimental and Analytical Study on the Shear-Strength of Partially Grouted Masonry Walls. Journal of Structural Engineering. 2020; 146 (8):04020147.
Chicago/Turabian StyleJamal Elmapruk; Mohamed A. ElGawady; Reza Hassanli. 2020. "Experimental and Analytical Study on the Shear-Strength of Partially Grouted Masonry Walls." Journal of Structural Engineering 146, no. 8: 04020147.
The compressive strength of concrete masonry depends on the dimensions of the test prisms. The available international masonry codes apply correction factors based on the height-to-thickness ratio to modify the strength obtained from different sizes of prisms. In this study, finite element models were developed to investigate the accuracy of this approach. Simplified micro-modeling method was used to simulate the behavior of masonry prisms which was verified against experimental results. A parametric study was then performed to examine the effect of key parameters on the compressive strength of masonry. The effect of the length-to-thickness ratio of masonry prisms was found to be significant on the compressive strength and should be considered together with the well understood effect of height-to-thickness ratio to calculate the correction factors. It was also shown that the current correction factors provided in the masonry codes lead to overestimating the strength of masonry prisms. New correction factors have been proposed accounting both the height-to-thickness and length-to-thickness ratio to reliably and safely estimate the compressive strength of masonry prisms.
Ali Abasi; Reza Hassanli; Thomas Vincent; Allan Manalo. Influence of prism geometry on the compressive strength of concrete masonry. Construction and Building Materials 2020, 264, 120182 .
AMA StyleAli Abasi, Reza Hassanli, Thomas Vincent, Allan Manalo. Influence of prism geometry on the compressive strength of concrete masonry. Construction and Building Materials. 2020; 264 ():120182.
Chicago/Turabian StyleAli Abasi; Reza Hassanli; Thomas Vincent; Allan Manalo. 2020. "Influence of prism geometry on the compressive strength of concrete masonry." Construction and Building Materials 264, no. : 120182.
The results of the first experimental study on the behavior of axial cyclically loaded rubberized concrete under active confinement are presented. Four different mixes of concrete with rubber replacement ratios of 0%–18% were considered to investigate the influence of the rubber content on the cyclic compressive behavior of concrete under different levels of lateral confining pressure ranging from 5 to 25 MPa. The results show that trends of the axial stress-axial strain and lateral strain-axial strain relationships of rubberized concrete under cyclic loading closely follow those of the corresponding monotonically loaded concrete. At a given confining pressure and rubber content, concrete exhibits a higher ductility under cyclic loading than under monotonic loading. Furthermore, cyclically loaded rubberized concrete specimens exhibit higher peak and residual stress ratios, but slightly lower peak and residual strain ratios compared with those of their monotonically loaded counterparts. Results also show that the unloading and reloading tangent modulus of rubberized concrete increase but axial plastic strain of rubberized concrete decreases with an increase in the confining pressure, following a trend similar to that of natural aggregate concrete. Owing to the lower unloading tangent modulus of the concrete with a higher rubber content, for a given confining pressure, the axial plastic strain of cyclically loaded rubberized concrete slightly decreases with increasing rubber replacement ratio. Based on the test results, simple model expressions were developed to predict the axial stress-strain relationship of actively confined rubberized concrete under cyclic axial compression. Promising findings of this study suggest that confined rubberized concrete can be used in column applications to reduce the environmental impact of waste tires and conserve nonrenewable natural resources.
Aliakbar Gholampour; Ali Fallah Pour; Reza Hassanli; Togay Ozbakkaloglu. Behavior of Actively Confined Rubberized Concrete under Cyclic Axial Compression. Journal of Structural Engineering 2019, 145, 04019131 .
AMA StyleAliakbar Gholampour, Ali Fallah Pour, Reza Hassanli, Togay Ozbakkaloglu. Behavior of Actively Confined Rubberized Concrete under Cyclic Axial Compression. Journal of Structural Engineering. 2019; 145 (11):04019131.
Chicago/Turabian StyleAliakbar Gholampour; Ali Fallah Pour; Reza Hassanli; Togay Ozbakkaloglu. 2019. "Behavior of Actively Confined Rubberized Concrete under Cyclic Axial Compression." Journal of Structural Engineering 145, no. 11: 04019131.
In this study, four steel-concrete-steel (SCS) sandwich beams were tested experimentally under incrementally increasing cyclic loading. Each beam had a length of 1000 mm, and upper and lower steel plates with 3 mm thickness sandwiched the concrete core which had a cross section of 150 mm × 150 mm. Two of the beams were constructed out of Rubcrete with welded and bolted shear connectors, the other two beams were constructed with welded shear connectors and either conventional concrete or lightweight expanded clay aggregate (LECA) concrete. The performance of the SCS sandwich beams performance including damage pattern, failure mode, and load-displacement response were compared. The results showed that while Rubcrete was able to provide similar concrete cracking behaviour and strength to that of conventional concrete, LECA concrete degraded the strength properties of SCS. Using bolted shear connectors instead of welded ones caused high number of cracks that resulted in a reduced ductility and deflection capacity of the beam before failure.
O. Youssf; R. Hassanli; J. E. Mills. Cyclic Behavior of Steel-Rubcrete-Steel Sandwich Beams. Proceedings of EECE 2020 2019, 807 -818.
AMA StyleO. Youssf, R. Hassanli, J. E. Mills. Cyclic Behavior of Steel-Rubcrete-Steel Sandwich Beams. Proceedings of EECE 2020. 2019; ():807-818.
Chicago/Turabian StyleO. Youssf; R. Hassanli; J. E. Mills. 2019. "Cyclic Behavior of Steel-Rubcrete-Steel Sandwich Beams." Proceedings of EECE 2020 , no. : 807-818.
This study presents the results of an experimental study on the cyclic compressive behavior of rubberized concrete under active confinement. Two different mixes of concretes with rubber replacement ratios of 0%, as a control mix, and 18% were prepared. The effects of the incorporation of rubber and the confining pressure on the cyclic compressive behavior of concrete were examined through tests of unconfined and actively confined concrete cylinders. The active confinement was applied by a Hoek cell at different confining pressures, including 5, 10, 15, 20, and 25 MPa. The results indicate that peak stress of concrete decreases, and the peak axial strain and corresponding lateral strain increase by incoporating rubber. The results also show that, at a given confining pressure, concrete exhibits a higher ductility under cyclic loading than that under monotonic loading.
A. Gholampour; A. Fallah Pour; R. Hassanli; Togay Ozbakkaloglu. Cyclic Behavior of Actively Confined Rubberized Concrete Under Axial Compression. Proceedings of EECE 2020 2019, 287 -293.
AMA StyleA. Gholampour, A. Fallah Pour, R. Hassanli, Togay Ozbakkaloglu. Cyclic Behavior of Actively Confined Rubberized Concrete Under Axial Compression. Proceedings of EECE 2020. 2019; ():287-293.
Chicago/Turabian StyleA. Gholampour; A. Fallah Pour; R. Hassanli; Togay Ozbakkaloglu. 2019. "Cyclic Behavior of Actively Confined Rubberized Concrete Under Axial Compression." Proceedings of EECE 2020 , no. : 287-293.
Double-skin tubular columns (DSTCs) have become a competitive candidate for column members due to their important advantages compared with conventional reinforced concrete columns, including their better weight-to-strength ratio and ease of construction. Using Rubcrete in hybrid DSTCs is of great interest due to the potential of this system to overcome the Rubcrete material deficiencies and to add more ductility, toughness, seismic resistance, confinement effectiveness, and environmentally-friendly features to that structural system compared to conventional concrete. In this paper, hybrid DSTCs made out of Rubcrete, sandwiched between a fibre reinforced polymer (FRP) tube and a steel tube, were tested. The examined variables were concrete sand or stone replacement ratio (0% and 20%), FRP wall thickness (1- and 2-layers), steel wall thickness (3.2 mm and 4.5 mm), void ratio (50% and 76%), and void shape (circular or square). The axial and lateral stress–strain responses were monitored, measured, and compared. According to this investigation, using Rubcrete in hybrid DSTCs can enhance the axial and hoop strain capacities, especially with fine rubber particles. It was also observed that the adverse influence of using rubber on column ultimate capacity was much lower in DSTC specimens, compared with that of unconfined Rubcrete columns. Therefore, using Rubcrete with fine rubber particles is recommended in DSTC structural columns.
Osama Youssf; Reza Hassanli; Julie E. Mills; Yan Zhuge. Axial Compression Behaviour of Hybrid Double-Skin Tubular Columns Filled with Rubcrete. Journal of Composites Science 2019, 3, 62 .
AMA StyleOsama Youssf, Reza Hassanli, Julie E. Mills, Yan Zhuge. Axial Compression Behaviour of Hybrid Double-Skin Tubular Columns Filled with Rubcrete. Journal of Composites Science. 2019; 3 (2):62.
Chicago/Turabian StyleOsama Youssf; Reza Hassanli; Julie E. Mills; Yan Zhuge. 2019. "Axial Compression Behaviour of Hybrid Double-Skin Tubular Columns Filled with Rubcrete." Journal of Composites Science 3, no. 2: 62.
This research extensively investigates how to enhance the mechanical performance of Rubcrete, aiming to move this type of concrete from the laboratory research level to a more practical use by the concrete industry. The effects of many different mixing procedures, chemical pre-treatments on the rubber particles, and the use of fibre additives, have been investigated for their impact upon Rubcrete workability, compressive strength, tensile strength, and flexural strength. The mixing procedure variables included mixing time and mixing order. The rubber pre-treatments utilized chemicals such as Sodium Hydroxide (NaOH), Hydrogen Peroxide (H2O2), Sulphuric acid (H2SO4), Calcium Chloride (CaCl2), Potassium Permanganate (KMnO4), Sodium Bisulphite (NaHsO3), and Silane Coupling Agent. Soaking rubber particles in tap water, or running them through water before mixing, were also tried as a pre-treatment of rubber particles. In addition, the effects of fibre additives such as steel fibres, polypropylene fibres, and rubber fibres, were assessed. X-ray photoelectron spectroscopy (XPS) analysis was utilised to examine some of the pre-treated rubber particles. The results showed that doubling the net mixing time of all mix constituents together enhanced the Rubcrete slump by an average of 22%, and the compressive strength by up to 8%. Mixing rubber with dry cement before adding to the mix increased the compressive strength by up to 3%. Pre-treatment using water was more effective than other chemicals in enhancing the Rubcrete workability. Regardless of the treatment material type, the longer the time of the treatment, the more cleaning of rubber occurred. Significant Rubcrete flexural strength increase occurred when using 1.5% fibre content of both steel fibre and polypropylene fibre.
Osama Youssf; Reza Hassanli; Julie E. Mills; William Skinner; Xing Ma; Yan Zhuge; Rajeev Roychand; Rebecca Gravina. Influence of Mixing Procedures, Rubber Treatment, and Fibre Additives on Rubcrete Performance. Journal of Composites Science 2019, 3, 41 .
AMA StyleOsama Youssf, Reza Hassanli, Julie E. Mills, William Skinner, Xing Ma, Yan Zhuge, Rajeev Roychand, Rebecca Gravina. Influence of Mixing Procedures, Rubber Treatment, and Fibre Additives on Rubcrete Performance. Journal of Composites Science. 2019; 3 (2):41.
Chicago/Turabian StyleOsama Youssf; Reza Hassanli; Julie E. Mills; William Skinner; Xing Ma; Yan Zhuge; Rajeev Roychand; Rebecca Gravina. 2019. "Influence of Mixing Procedures, Rubber Treatment, and Fibre Additives on Rubcrete Performance." Journal of Composites Science 3, no. 2: 41.
Due to the structural and economic features of steel–concrete–steel (SCS) structural systems compared with conventional reinforced concrete ones, they are now used for a range of structural applications. Rubcrete, in which crumbed rubber from scrap tires partially replaces mineral aggregates in concrete, can be used instead of conventional concrete. Utilizing rubber waste in concrete potentially results in a more ductile lightweight concrete that can introduce additional features to the SCS structural members. This study aimed to explore different concrete core materials in SCS beams and the appropriate shear connectors required. In this study, four SCS sandwich beams were tested experimentally under incrementally increasing flexure cyclic loading. Each beam had a length of 1000 mm, and upper and lower steel plates with 3 mm thickness sandwiched the concrete core, which had a cross-section of 150 mm × 150 mm. Two of the beams were constructed out of Rubcrete core with welded and bolted shear connectors, while the other two beams were constructed with welded shear connectors and either conventional concrete or lightweight expanded clay aggregate (LECA) concrete cores. The performance of the SCS sandwich beams including damage pattern, failure mode, load-displacement response, and energy dissipation behavior was compared. The results showed that, while Rubcrete was able to provide similar concrete cracking behavior and strength to that of conventional concrete, LECA concrete degraded the strength properties of SCS. Using bolted shear connectors instead of welded ones caused a high number of cracks that resulted in a reduced ductility and deflection capacity of the beam before failure. The rubberized concrete specimen presented an improved ductility and deflection capacity compared with its conventional concrete counterpart.
Osama Youssf; Reza Hassanli; Julie E. Mills; Xing Ma; Yan Zhuge. Cyclic Performance of Steel–Concrete–Steel Sandwich Beams with Rubcrete and LECA Concrete Core. Journal of Composites Science 2019, 3, 5 .
AMA StyleOsama Youssf, Reza Hassanli, Julie E. Mills, Xing Ma, Yan Zhuge. Cyclic Performance of Steel–Concrete–Steel Sandwich Beams with Rubcrete and LECA Concrete Core. Journal of Composites Science. 2019; 3 (1):5.
Chicago/Turabian StyleOsama Youssf; Reza Hassanli; Julie E. Mills; Xing Ma; Yan Zhuge. 2019. "Cyclic Performance of Steel–Concrete–Steel Sandwich Beams with Rubcrete and LECA Concrete Core." Journal of Composites Science 3, no. 1: 5.
This book reports on a comprehensive analytical, experimental and numerical study on the flexural response of post-tensioned masonry walls under in-plane loads. It explores an important mechanism in this new generation of structural walls, called “Self-centering”. This mechanism can reduce residual drifts and structural damage during earthquake ground motion, and is particularly favorable for structures which are designed for immediate occupancy performance levels. The book reports on the development and verification of a finite element model of post-tensioned masonry walls. It describes a detailed parametric study to predict the strength of post-tensioned masonry walls. New design methodologies and expressions are developed to predict the flexural strength and force-displacement response of post-tensioned masonry. Experimental study is carried out to better understand the behavior of post-tensioned masonry walls and also to evaluate the accuracy of the proposed design procedure and expressions. The book also includes an introduction to current research on unbounded post-tensioned masonry walls, together with an extensive analysis of previously published test results.
Reza Hassanli. Behavior of Unbounded Post- tensioned Masonry Walls. Springer Theses 2019, 1 .
AMA StyleReza Hassanli. Behavior of Unbounded Post- tensioned Masonry Walls. Springer Theses. 2019; ():1.
Chicago/Turabian StyleReza Hassanli. 2019. "Behavior of Unbounded Post- tensioned Masonry Walls." Springer Theses , no. : 1.
This paper presents an experimental study on the axial compressive behavior of concrete columns retrofitted and confined by fiber-reinforced concrete (FRC) jackets. Three different engineered cementitious composite (ECC) mixes containing high-strength polyethylene fibers at three fiber volume fractions of 0%, 1%, and 2%, and one ultra-high performance cementitious composite (UHP) mix at fiber volume fraction of 4%, were prepared to produce FRC jackets around the core concrete. Horizontal stirrups were used in the FRC jackets with three different horizontal reinforcement ratios to investigate the effect of the level of confinement and the interaction between the conventional reinforcement and fibers. The results show that specimens having no fiber or stirrup in their retrofitting jacket exhibit a brittle behavior and only those containing both stirrup and fiber provide a ductile behavior. It was also observed that the lateral strain of the jacket layer at a given axial strain increased with an increase in the fiber content, indicating an increased rate of dilation for the jacket concrete at a higher fiber volume fraction. It was also found that the best solution to enhance both ductility and strength of columns using FRC jacket is to include a minimum of both fiber content and reinforcement in the jacketing layer. The observations of this study reveal the great potential of the use of FRC jackets in retrofitting of structural members, especially columns in seismic regions.
Aliakbar Gholampour; Reza Hassanli; Julie Mills; Thomas Vincent; Minoru Kunieda. Experimental investigation of the performance of concrete columns strengthened with fiber reinforced concrete jacket. Construction and Building Materials 2018, 194, 51 -61.
AMA StyleAliakbar Gholampour, Reza Hassanli, Julie Mills, Thomas Vincent, Minoru Kunieda. Experimental investigation of the performance of concrete columns strengthened with fiber reinforced concrete jacket. Construction and Building Materials. 2018; 194 ():51-61.
Chicago/Turabian StyleAliakbar Gholampour; Reza Hassanli; Julie Mills; Thomas Vincent; Minoru Kunieda. 2018. "Experimental investigation of the performance of concrete columns strengthened with fiber reinforced concrete jacket." Construction and Building Materials 194, no. : 51-61.
This paper introduces an innovative system of retaining walls named “pre-stressed segmental retaining walls (PSRWs)”. In this system, interlocking blocks are assembled together with dry joints (mortarless) and the integrity of the wall is maintained by pre-stressing forces. The pro-posed system has a collection of advantages over the conventional systems for construction of cantilever retaining walls or mechanically stabilized earth walls. In particular precast concrete/masonry segments can be incorporated which reduces the construction time and cost for cantilever type structures and if combined with mechanically stabilized earth wall system, it can reduce the number of layers of reinforcement and add flexibility to the design. These walls will be suitable for both water front and soil retention purposes.
Reza Hassanli; Rajibul Karim; Mizanur Rahman; Arman Kamalzadeh; Julie Mills; Mehdi Javadi. Pre-stressed Segmental Retaining Walls (PSRWs). Advancements in Geotechnical Engineering 2018, 187 -196.
AMA StyleReza Hassanli, Rajibul Karim, Mizanur Rahman, Arman Kamalzadeh, Julie Mills, Mehdi Javadi. Pre-stressed Segmental Retaining Walls (PSRWs). Advancements in Geotechnical Engineering. 2018; ():187-196.
Chicago/Turabian StyleReza Hassanli; Rajibul Karim; Mizanur Rahman; Arman Kamalzadeh; Julie Mills; Mehdi Javadi. 2018. "Pre-stressed Segmental Retaining Walls (PSRWs)." Advancements in Geotechnical Engineering , no. : 187-196.
Segmental self-centering columns are an advantageous construction choice in earthquake prone areas due to their minimal or even zero residual deformation and their low repair/downtime costs. This research investigated the behavior of segmental rectangular column members with a high cross-sectional length to width ratio under different loading directions, with the aim of potentially extending the concept of segmental self-centering columns to wall members, such as shear walls and retaining walls. The main parameters of this study were the direction of loading: in-plane (strong-axis bending) and out-of-plane (weak-axis bending), provision (or absence) of reinforcement, and the type of concrete material (conventional concrete or rubberized concrete). Eight concrete columns with a cross-sectional length to width ratio of 2.5 and consisting of three concrete segments with dry joints in between, were tested under reversed-cyclic lateral loading. A pre-stressing force of 100kN, corresponding to a stress of 2.8 MPa on the column, was applied using unbonded post-tensioning (PT) bars. The results indicated that although in-plane loaded columns had a higher load capacity, they exhibited a less ductile response, higher level of damage and higher loss in the PT force, compared with the out-of-plane loaded columns. The total equivalent viscous damping and its variation was very small in all tested specimens, and it increased slightly as the drift ratio increased. Empirical equations were developed to express the damping as a function of drift ratio. It was also concluded that in the out-of-plane loaded specimens, the effect of reinforcement on the load-displacement response was insignificant. In rectangular columns with high length-to-width ratio, under out-of-plane loading, if a minimum level of axial pre-stressing is applied (to prevent shear or sliding failure), no structural reinforcement is required. In addition, the strength reduction due to using rubber in concrete at the structural level was much lower than that at the material level. The results of this study can potentially be applied to segmental concrete walls due to the high length-to-width ratios of the tested columns.
Reza Hassanli; Osama Youssf; Julie Mills; Rajibul Karim; Thomas Vincent. Performance of segmental self-centering rubberized concrete columns under different loading directions. Journal of Building Engineering 2018, 20, 285 -302.
AMA StyleReza Hassanli, Osama Youssf, Julie Mills, Rajibul Karim, Thomas Vincent. Performance of segmental self-centering rubberized concrete columns under different loading directions. Journal of Building Engineering. 2018; 20 ():285-302.
Chicago/Turabian StyleReza Hassanli; Osama Youssf; Julie Mills; Rajibul Karim; Thomas Vincent. 2018. "Performance of segmental self-centering rubberized concrete columns under different loading directions." Journal of Building Engineering 20, no. : 285-302.