The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Da Chen - One of the best experts on this subject based on the ideXlab platform.
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Seismic behavior of reinforced engineered Cementitious Composite members and reinforced concrete/engineered Cementitious Composite members: A review
'Wiley', 2020Co-Authors: Hou Lijun, Xu Ran, Da Chen, Xu Shilang, Aslani FarhadAbstract:Seismic performance is of paramount importance for structures in regions with high seismic risk. Engineered Cementitious Composite (ECC) exhibits tensile strain hardening behavior and excellent crack dispersion capacity, as well as good workability. The application of ECC material may be a feasible way to improve the seismic behavior of engineering structures. This paper presents a comprehensive review of experimental and simulation studies concerning seismic behavior of reinforced ECC members and reinforced concrete/ECC Composite members. The review is mainly focused on design programs for structural members and their seismic response behavior. The effectiveness of the application of ECC for seismic improvement is discussed. Several design recommendations are provided, based on comparison of the related studies. © 2019 fib. International Federation for Structural Concret
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flexural behaviour of corroded reinforced concrete beams repaired with ultra high toughness Cementitious Composite
Construction and Building Materials, 2019Co-Authors: Farhad Aslani, Jin Wang, Lijun Hou, Ting Huang, Chun Shen, Da ChenAbstract:Abstract The repair of corroded reinforced concrete (RC) structures is necessary to improve their serviceability. Ultra-high toughness Cementitious Composite (UHTCC), characterised by excellent tensile behaviour, crack control capacity, and durability, shows great potential for the repair and strengthening of corroded members, especially in harsh marine environments. This paper presents an experimental study and a theoretical analysis of the flexural performance of corroded RC beams repaired with UHTCC. The experimental results indicated that macro cracks in concrete were transformed into multiple fine cracks and a slight nonlinear strain distribution was observed along the sectional depth. The replacement of damaged concrete with UHTCC can recover the initial load-carrying capacity at corrosion ratios within 11.2%. After yielding of beams, the development of UHTCC-concrete interface crack in the pure bending region was beneficial to ductility improvement. A theoretical model considering the effect of pitting corrosion was proposed for calculating flexural capacity of repaired beams.
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effect of corrosion on bond behaviors of rebar embedded in ultra high toughness Cementitious Composite
Construction and Building Materials, 2017Co-Authors: Lijun Hou, Hong Liu, Ning Zhuang, Da ChenAbstract:Abstract The bond between corroded rebar and ultra-high toughness Cementitious Composite (UHTCC) is a key factor in the mechanical properties of corroded reinforced concrete members repaired using UHTCC. This paper presents an experimental study on bond behaviors of UHTCC and corroded reinforcement obtained in a concrete environment through central pull-out tests. The experimental results revealed that all the UHTCC specimens failed in pull-out and that almost all showed an apparent average slip plateau. The post-peak bond behavior was improved with an increase in corrosion ratio. The change in bond strength with corrosion ratio is related to bond length. Bond toughness first rose and then decreased with corrosion ratio, but still remained close to that of non-corroded samples at about 15% of corrosion ratio. An empirical model was proposed to predict the bond strength between corroded rebar and UHTCC, and a good agreement was obtained.
Lijun Hou - One of the best experts on this subject based on the ideXlab platform.
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flexural behaviour of corroded reinforced concrete beams repaired with ultra high toughness Cementitious Composite
Construction and Building Materials, 2019Co-Authors: Farhad Aslani, Jin Wang, Lijun Hou, Ting Huang, Chun Shen, Da ChenAbstract:Abstract The repair of corroded reinforced concrete (RC) structures is necessary to improve their serviceability. Ultra-high toughness Cementitious Composite (UHTCC), characterised by excellent tensile behaviour, crack control capacity, and durability, shows great potential for the repair and strengthening of corroded members, especially in harsh marine environments. This paper presents an experimental study and a theoretical analysis of the flexural performance of corroded RC beams repaired with UHTCC. The experimental results indicated that macro cracks in concrete were transformed into multiple fine cracks and a slight nonlinear strain distribution was observed along the sectional depth. The replacement of damaged concrete with UHTCC can recover the initial load-carrying capacity at corrosion ratios within 11.2%. After yielding of beams, the development of UHTCC-concrete interface crack in the pure bending region was beneficial to ductility improvement. A theoretical model considering the effect of pitting corrosion was proposed for calculating flexural capacity of repaired beams.
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effect of corrosion on bond behaviors of rebar embedded in ultra high toughness Cementitious Composite
Construction and Building Materials, 2017Co-Authors: Lijun Hou, Hong Liu, Ning Zhuang, Da ChenAbstract:Abstract The bond between corroded rebar and ultra-high toughness Cementitious Composite (UHTCC) is a key factor in the mechanical properties of corroded reinforced concrete members repaired using UHTCC. This paper presents an experimental study on bond behaviors of UHTCC and corroded reinforcement obtained in a concrete environment through central pull-out tests. The experimental results revealed that all the UHTCC specimens failed in pull-out and that almost all showed an apparent average slip plateau. The post-peak bond behavior was improved with an increase in corrosion ratio. The change in bond strength with corrosion ratio is related to bond length. Bond toughness first rose and then decreased with corrosion ratio, but still remained close to that of non-corroded samples at about 15% of corrosion ratio. An empirical model was proposed to predict the bond strength between corroded rebar and UHTCC, and a good agreement was obtained.
Ali N Algemeel - One of the best experts on this subject based on the ideXlab platform.
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experimental investigation of basalt textile reinforced engineered Cementitious Composite under apparent hoop tensile loading
Journal of building engineering, 2019Co-Authors: Ali N Algemeel, Yan Zhuge, Osama YoussfAbstract:Abstract Over the past decade, conventional mortar reinforced by textile has shown a promising performance as a Composite material for repairing of both concrete and masonry structures compared with that of reinforced by discrete fibres. However, the relatively brittleness of the conventional mortar adversely affects the efficiency of the textile reinforced mortar (TRM) Composite system due to the premature textile fracture. Engineered Cementitious Composite (ECC) is a well-known high-performance Cementitious Composite for its superior tensile strain-hardening properties and high impact resistance compared with both conventional mortar and discrete fibres reinforced mortar. In this paper, the behaviour of ECC reinforced by basalt textile was investigated and compared with that of TRM technique. The behaviour of ring-shaped specimens subjected to apparent hoop tensile loading was studied. The response characteristics including: tensile strength, failure modes, energy absorption, toughness index, strain behaviour, and the correlations between tensile strength and energy absorption were investigated. The results revealed that ECC is a promising material that can effectively enhance the performance of textile reinforced mortar. Replacing conventional mortar by ECC resulted in a notable increase in the peak tensile load by 241% indicating a dramatic effect of the ECC-based matrix.
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using textile reinforced engineered Cementitious Composite for concrete columns confinement
Composite Structures, 2019Co-Authors: Ali N Algemeel, Yan ZhugeAbstract:Abstract Confining concrete structures with fibre reinforced polymer (FRP) is proven to be an efficient technique in improving the dilation and axial performance of concrete columns. However, a few drawbacks of using FRP, such as brittleness of FRP sheet and poor performance of the material at high temperatures, have been found in recent years. A feasibility study of a newly developed strengthening system, basalt fibre textile reinforced engineered Cementitious Composite (ECC), is presented in this paper. A combination of basalt textile and ECC-based matrix was used in this research to evaluate how effectively this technique to confine concrete columns. All the specimens were tested under axial load, which was applied to the concrete cores only to create pure hoop tensile stress at the confinement layer. The experimental results revealed that ECC is a promising material that can effectively bond to textile fibres. A new confinement model was also developed to predict the compressive strength for textile reinforced ECC confined concrete. The technique could be an effective alternative to overcome the drawbacks of the traditional strengthening methods.
Surendra P Shah - One of the best experts on this subject based on the ideXlab platform.
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self healing efficiency and crack closure of smart Cementitious Composite with crystalline admixture and structural polyurethane
Construction and Building Materials, 2020Co-Authors: Caihong Xue, Zhihui Sun, Surendra P ShahAbstract:Abstract The crack closure and self-healing efficiency of smart self-healing Cementitious Composite can effectively reveal the mechanism of self-healing performance recovery. This study focused on effects of crack healing on crack closure and mechanical performance recovery of crack-healed Cementitious Composite, including flexural compressive behaviours. Meanwhile, several parameters were defined to quantify the efficiency of mechanical performance recovery efficiency for self-healing Cementitious Composite. Furthermore, the interfaces between self-healing products and crack surface were analyzed and compared to provide understanding insight to the self-healing recovery. It is found that the bonding interface dominated the flexural strength recovery, and therefore autonomous self-healing yielded the maximum self-healing efficiency. On the other hand, the stiffness damage recovery index under compression is found to be an effective parameter to evaluate the inner crack healing, which slightly depends on the bonding interface. The related results indicate that the development of smart self-healing Cementitious Composite should consider the bonding between self-healing product and crack surface to improve the self-healing recovery efficiency for engineering application.
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investigation on physicochemical and piezoresistive properties of smart mwcnt Cementitious Composite exposed to elevated temperatures
Cement & Concrete Composites, 2020Co-Authors: Wenkui Dong, Kejin Wang, Baoguo Han, Daichao Sheng, Surendra P ShahAbstract:Abstract Piezoresistivity of smart carbon nanotube/Cementitious Composite has been experimentally investigated, but the piezoresistive performance had been rarely studied when exposed to elevated temperatures. In this study, the physicochemical and mechanical properties, and piezoresistive behaviours of multi-walled carbon nanotube (MWCNT) reinforced smart Cementitious Composite were investigated under heat treatments of elevated temperatures of 300 °C and 600 °C. The microstructures, crystal deterioration and thermal gravity relationships were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and thermos-gravimetric (TG) analysis. The results show that the compressive strength and elastic modulus of MWCNT/Cementitious Composite after heat treatments gradually decreased, especially under the high temperature of 600 °C. There was a sudden growth of fractional changes of resistivity (FCR) after heat treatment. The higher temperature treatments led to more extensive sudden increase in the piezoresistivity. In the linear part of the relationship curves of FCR to the strain, the gauge factor even increased at the temperature of 300 °C. Moreover, the mechanism for the altered piezoresistivity was fundamentally explained and discussed by the MWCNT purification and destructions of MWCNT, cement matrix and agglomerations after heat treatments. Therefore, the related outcomes will promote the understanding and application of smart MWCNT/Cementitious Composite for structural health monitoring (SHM) under extreme environments.
Farhad Aslani - One of the best experts on this subject based on the ideXlab platform.
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flexural behaviour of corroded reinforced concrete beams repaired with ultra high toughness Cementitious Composite
Construction and Building Materials, 2019Co-Authors: Farhad Aslani, Jin Wang, Lijun Hou, Ting Huang, Chun Shen, Da ChenAbstract:Abstract The repair of corroded reinforced concrete (RC) structures is necessary to improve their serviceability. Ultra-high toughness Cementitious Composite (UHTCC), characterised by excellent tensile behaviour, crack control capacity, and durability, shows great potential for the repair and strengthening of corroded members, especially in harsh marine environments. This paper presents an experimental study and a theoretical analysis of the flexural performance of corroded RC beams repaired with UHTCC. The experimental results indicated that macro cracks in concrete were transformed into multiple fine cracks and a slight nonlinear strain distribution was observed along the sectional depth. The replacement of damaged concrete with UHTCC can recover the initial load-carrying capacity at corrosion ratios within 11.2%. After yielding of beams, the development of UHTCC-concrete interface crack in the pure bending region was beneficial to ductility improvement. A theoretical model considering the effect of pitting corrosion was proposed for calculating flexural capacity of repaired beams.
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Fabrication and characterization of an engineered Cementitious Composite with enhanced fire resistance performance
Journal of Cleaner Production, 2019Co-Authors: Farhad Aslani, Lining WangAbstract:Abstract This study evaluated the fire resistance of a lightweight engineered Cementitious Composite under elevated temperature up to 900 °C. To achieve lightweight, waste recycled hollow glass microspheres, which comprise 45% of waste glass were obtained as an ultra-high-performance lightweight filler. And carbon nanofibre was added to maintain the mechanical properties of engineered Cementitious Composite while reducing the weight. This study aims to thoroughly understand the effect of hollow glass microsphere, carbon nanofibre, and their combination to the fire resistance of engineered Cementitious Composite. Three different types of hollow glass microspheres and four different types of carbon nanofibers were conducted in this research. The results showed that engineered Cementitious Composite contains both hollow glass microsphere and carbon nanofibre presented high fire resistance, which is able to remain 50% of original strength when exposed to high temperature at 900 °C. The compressive strength of Composite was found to be slightly influenced with using hollow glass microsphere, although the total densities were reduced. Carbon nanofibre contribute to the Composite’s strength of both normal and lightweight engineered Cementitious Composite and it is able to enhance mechanical performance when the samples are under elevated temperatures. Microscopy study found that carbon nanofibre contribute to the Composite rehydration at high temperature. The work provides a promising way to develop lightweight engineered Cementitious Composite with high mechanical performance and fire resistance, and proved the possibility of partially replacing Cementitious material with hollow glass microsphere.