The Experts below are selected from a list of 2103 Experts worldwide ranked by ideXlab platform

Taito Miura - One of the best experts on this subject based on the ideXlab platform.

  • numerical simulation of bond degradation subjected to corrosion induced crack by simplified rebar and interface model using rbsm
    Construction and Building Materials, 2020
    Co-Authors: Yizhou Yang, Hikaru Nakamura, Yoshihito Yamamoto, Taito Miura
    Abstract:

    Abstract The bond degradation subjected to corrosion-induced crack was investigated numerically using 3D Rigid Body Spring Model (RBSM) in which rebar was modeled by solid elements without modeling explicitly the details of rebar ribs. The proposed numerical model considers both corrosion expansion and shear stress transfer behavior through the interface elements. Validation of proposed model showed that it is possible to obtain reasonable bond performance of non-corroded specimen as meso-scale models. By comparison with experimental results, the proposed model was verified to reproduce the bond deterioration considering corrosion-induced crack with different Concrete Cover Thickness. Moreover, bond deterioration mechanism subjected to corrosion-induced crack was clarified through the crack development and stress distribution of Concrete and was found to be the combined effects of degradation of the compressive stress in diagonal compression struts and ring-tension around rebar. Bond deterioration of specimen with larger Concrete Cover is more sensitive to formation of corrosion crack.

  • crack patterns of Concrete with a single rebar subjected to non uniform and localized corrosion
    Construction and Building Materials, 2016
    Co-Authors: Di Qiao, Hikaru Nakamura, Yoshihito Yamamoto, Taito Miura
    Abstract:

    Abstract This study aims to investigate the effects of corrosion distribution, specifically non-uniform and localized corrosion, on cracks propagation in Concrete. Different corrosion distributions along rebar length were simulated using a sodium chloride pond with various sizes set on the Concrete Cover, and a direct current was applied to accelerate the corrosion process. The test results showed that the crack pattern is more influenced by corrosion distribution than by Concrete Cover Thickness. The cracking mechanism was analyzed using the Rigid Body Spring Method with a corrosion-expansion model, which utilized a set of experimental data relating to corrosion distribution. The crack patterns are simulated reasonably well. The analysis also indicated that the internal crack pattern is closely related to Concrete surface deformation.

Jiyu Tang - One of the best experts on this subject based on the ideXlab platform.

  • effect of high temperature on the bond performance between basalt fibre reinforced polymer bfrp bars and Concrete
    Construction and Building Materials, 2017
    Co-Authors: Chenchen Li, Yinglai Wang, Jiyu Tang
    Abstract:

    Abstract The use of basalt fibre reinforced polymer (BFRP) bars as a reinforcing material has gained increasing interest worldwide. However, few studies have reported on the bonding performance of the bars in Concrete when exposed to high temperatures. This paper investigates the effects of seven variable parameters, namely, temperature, bonded length, diameter and type of FRP bars, Concrete strength, Concrete Cover Thickness and a fireproof coating material on the Concrete surface, on the bond stress-slip curves, failure modes, and bond strength of the BFRP bars. Glass fibre reinforced polymer (GFRP) bars were used for comparison. BFRP bar pullout specimens exhibited similar bond stress-slip curves at both room and high temperatures, but the peak bond stress and the slope decreased when the temperature increased. The bond strength declined gradually with the increase of the temperature, and the effect of temperature on the bond strength of the GFRP bar pullout specimens was more severe than that of the BFRP bar pullout specimens. At temperatures from 70 °C to 220 °C, the bond strength decreased by 2.45–14.24%. At 270 °C, the bond strength declined by approximately 32%. At 350 °C, the residual bond strength was 12.20–23.14% of their original values.

O U Jinping - One of the best experts on this subject based on the ideXlab platform.

  • bond slip constitutive model between gfrp steel wire composite rebars and Concrete
    Engineering mechanics, 2009
    Co-Authors: O U Jinping
    Abstract:

    The bond behavior is the basis of collaboration between GFRP/steel wire composite rebar and Concrete,and the bond-slip constitutive model is the overall reflection of bond behavior of GFRP/steel wire composite rebar embedded in Concrete.Thus,the research on the constitutive model of bond-slip relationship between GFRP/steel wire composite rebar and Concrete has theoretical and practical value in the performance analysis,design theory and engineering application of Concrete structures reinforced with GFRP/steel wire composite rebars.In this study,180 pull-out specimens were tested to investigate the effect of rebar rib spacing,rebar diameter,embedded length,Concrete compressive strength,Concrete Cover Thickness,and Concrete cast depth on bond behavior,and the bond-slip curves were obtained for each specimen.Based on the existing bond-slip constitutive models worldwidely,one new bond-slip constitutive model was proposed according to the analysis of bond failure,bond-slip mechanism,and loading process of GFRP/steel wire composite rebar.The newly built bond-slip constitutive model was compared with the test results and existing bond-slip models.It is explicit in physical concept and simple in form,and fits the whole loading process of GFRP ribbed rebar and the test results well.

  • experimental study and design recommendation on Concrete Cover Thickness of gfrp steel wire composite rebars
    Journal of Building Structures, 2009
    Co-Authors: O U Jinping
    Abstract:

    The Concrete Cover Thickness of GFRP/steel wire composite rebar in Concrete structures is critical to the safety,serviceability and durability of the structures.Using the pull-out test,69 specimens were tested to measure the bond strength,the slip both at the loaded and free ends,and to calculate the load-slip relationship curves.The test parameters were the GFRP/steel wire composite rebar diameter,Concrete compressive strength,and the Concrete Cover Thickness.Based on the analysis of the test results,the critical value of slip at both loaded and free ends and the critical value of bond strength were obtained,and the design recommendation on Concrete Cover Thickness of Concrete structures reinforced with GFRP/steel wire composite rebars was suggested.The test results and design recommendation can provide theoretical basis and references to the practical applications of the GFRP/steel wire composite rebars and to establishment of the related criterions.

Michel Ghosn - One of the best experts on this subject based on the ideXlab platform.

  • chloride induced corrosion of reinforced Concrete bridge decks
    Cement and Concrete Research, 2002
    Co-Authors: M K Kassir, Michel Ghosn
    Abstract:

    Abstract A closed-form solution is developed to predict the corrosion initiation time of reinforced Concrete bridge decks using measured time varying surface chloride accumulations. The data base for the surface chlorides are core measurements at a shallow depth below the surface of 15 bridge decks in the snow belt region. The data base was collected during the bridges' biennial inspections over a period of 15 years. Regression analysis is used to represent the surface chlorides by an exponential variation with time. The time predicted to initiate corrosion is computed for different values of the effective diffusion coefficient and the Concrete Cover Thickness. The results are compared to the constant surface accumulation model commonly used in the literature. As expected, the corrosion initiation based on constant chloride accumulation at the surface is faster (in some case by up to 100%) than the initiation time calculated from actual chloride concentration data. Such results are useful for the realistic estimation of the service lives of bridge decks and for scheduling bridge deck maintenance and rehabilitation programs.

Leila Cristina Meneghetti - One of the best experts on this subject based on the ideXlab platform.

  • chloride accelerated test influence of silica fume water binder ratio and Concrete Cover Thickness
    Revista IBRACON de Estruturas e Materiais, 2013
    Co-Authors: Elias Pereira, A Resende, M H F De Medeiros, Leila Cristina Meneghetti
    Abstract:

    In developed countries like the UK, France, Italy and Germany, it is estimated that spending on maintenance and repair is practically the same as investment in new constructions. Therefore, this paper aims to study different ways of interfering in the corrosion kinetic using an accelerated corrosion test - CAIM, that simulates the chloride attack. The three variables are: Concrete Cover Thickness, use of silica fume and the water/binder ratio. It was found, by analysis of variance of the weight loss of the steel bars and chloride content in the Concrete Cover Thickness, there is significant influence of the three variables. Also, the results indicate that the addition of silica fume is the path to improve the corrosion protection of low water/binder ratio Concretes (like 0.4) and elevation of the Concrete Cover Thickness is the most effective solution to increase protection of high water/binder ratio Concrete (above 0.5).

  • chloride accelerated test influence of silica fume water binder ratio and Concrete Cover Thickness ensaio acelerado por cloretos efeito da silica ativa relacao agua aglomerante e espessura de cobrimento do concreto
    2013
    Co-Authors: Elias Pereira, A Resende, M H F De Medeiros, Leila Cristina Meneghetti
    Abstract:

    In developed countries like the UK, France, Italy and Germany, it is estimated that spending on maintenance and repair is practically the same as investment in new constructions. Therefore, this paper aims to study different ways of interfering in the corrosion kinetic using an accelerated corrosion test – CAIM, that simulates the chloride attack. The three variables are: Concrete Cover Thickness, use of silica fume and the water/ binder ratio. It was found, by analysis of variance of the weight loss of the steel bars and chloride content in the Concrete Cover Thickness, there is significant influence of the three variables. Also, the results indicate that the addition of silica fume is the path to improve the corrosion protection of low water/binder ratio Concretes (like 0.4) and elevation of the Concrete Cover Thickness is the most effective solution to increase protection of high water/binder ratio Concrete (above 0.5).