Yousif H.A.,University of Technology, Iraq |
Yousif H.A.,Building Research Center |
Al-Hadeethi F.F.,Applied Scientific Research |
Al-Nabilsy B.,Conformity and Quality Institutional Company |
Abdelhadi A.N.,Applied Scientific Research
International Journal of Corrosion | Year: 2014
A research work was carried out to investigate the effectiveness of high-strength self-compacting concrete (SF-R) in controlling corrosion of embedded steel. Reinforced concrete cylinders and plain cubes were subjected to 5% NaCl solution. Slump flow, J-ring, V-funnel, compressive strength, electrical resistance, and electrochemical tests were conducted. Corrosion resisting characteristics of steel were examined by monitoring corrosion potential, polarization resistance, corrosion currents, and Tafel plots. The relationship between corrosion current density and corrosion potential was established. Results were compared with characteristics of a grade 40 MPa reference concrete (R) and grade 70 MPa conventional self-compacting concrete (SP). Results indicated that at 270 days of exposure, the corrosion currents for steel in SF-R were 63- and 16-fold lower compared to those of steel in R and SP concretes, respectively. This concrete showed a considerable increase in electrical resistance and compressive strength of 96 MPa at 28 days of exposure. Relying on corrosion risk classification based on corrosion current densities and corrosion potentials, the steel in SF-R concrete is definitely in the passive condition. The splendid durability performance of steel in SF-R concrete linked to adorable self-compacting features could furnish numerous opportunities for future structural applications in severe environmental conditions. © 2014 Hana A. Yousif et al.
Kim Y.,University of Tokyo |
Kabeyasawa T.,University of Tokyo |
Matsumori T.,Hyogo Earthquake Engineering Research Center |
Kabeyasawa T.,Building Research Center
Earthquake Engineering and Structural Dynamics | Year: 2012
A full-scale shake table test on a six-story reinforced concrete wall frame structure was carried out at E-Defense, the world's largest three-dimensional earthquake simulation facility, in January 2006. Story collapse induced from shear failure of shear critical members (e.g., short columns and shear walls) was successfully produced in the test. Insights gained into the seismic behavior of a full-scale specimen subjected to severe earthquake loads are presented in this paper. To reproduce the collapse process of the specimen and evaluate the ability of analytical tools to predict post-peak behavior, numerical simulation was also conducted, modeling the seismic behavior of each member with different kinds of models, which differ primarily in their ability to simulate strength decay. Simulated results showed good agreement with the strength-degrading features observed in post-peak regions where shear failure of members and concentrated deformation occurred in the first story. The simulated results tended to underestimate observed values such as maximum base shear and maximum displacement. The effects of member model characteristics, torsional response, and earthquake load dimensions (i.e., three-dimensional effects) on the collapse process of the specimen were also investigated through comprehensive dynamic analyses, which highlighted the following seismic characteristics of the full-scale specimen: (i) a model that is incapable of simulating a specimen's strength deterioration is inadequate to simulate the post-peak behavior of the specimen; (ii) the torsional response generated from uniaxial eccentricity in the longitudinal direction was more significant in the elastic range than in the inelastic range; and (iii) three-dimensional earthquake loads (X-Y-Z axes) generated larger maximum displacement than any other loading cases such as two-dimensional (X-Y or Y-Z axes) or one-dimensional (Y axis only) excitation. © 2011 John Wiley & Sons, Ltd..
Khellafi A.M.,Ziane Achour University of Djelfa |
Harichane Z.,University of Hassiba Ben Bouali Chlef |
Afra H.,Building Research Center |
Sadouki A.,University of Hassiba Ben Bouali Chlef
International Journal of Geotechnical Earthquake Engineering | Year: 2013
On May 21st, 2003, the north Algeria was stricken by a 6.8 magnitude earthquake which was felt over a distance of 250 km from the epicenter, which is localized in Mediterranean Sea at 10 km from the coast. During this event, several ground accelerations were recorded by the instrumentation network of the National Center of Applied Research in Earthquake Engineering (CGS). The records analysis revealed an important difference in peak ground acceleration (PGA) between two close stations (0.58g and 0.33g, respectively, in East-West direction) at about 20 km from the earthquake epicenter. Also, two other record stations, located in the Mitidja basin, at about 29 km and 86 km from the earthquake epicenter, respectively, showed a high level of acceleration: PGAs of 0.54g and 0.16g. So, the authors attempt in this paper to analyze these records through the characteristics of strong ground motions, the effects of different parameters such as damping ratios, soil conditions and epicentral distance on normalized response spectra. Also, the quantification of site effects during this earthquake is analyzed. Then, the authors compare the near-field mean response spectra obtained during this earthquake with the Algerian seismic design spectra (RPA99 - 2003 version) and with two other well-known design spectra: Eurocode 8 and UBC97 in order to contribute to the future revision of RPA99. Copyright © 2013 IGI Global.
Harichane Z.,University of Hassiba Ben Bouali Chlef |
Chehat A.,University of Hassiba Ben Bouali Chlef |
Afra H.,Building Research Center
Electronic Journal of Geotechnical Engineering | Year: 2011
In order to take into account the non linear behaviour of soils in an earthquake response analysis, a visco-elasto-plastic model is used. The present study consists, firstly, in a rheological modelling of the soil material, assuming a completely undrained condition. Then, a space representation is done by using linear one-dimensional finite elements with two nodes. Damping is taken into account by the Rayleigh's damping matrix. The seismic response is obtained in terms of accelerations at the free surface of each soil profile of the two studied sites: Garner Valley site (USA) and Dar El Beida site (Algeria), to base rock excitations. The soil profile behavior is influenced by the damping matrix model and the vibration level. © 2011 ejge.