Proceedings of the World Congress on Civil, Structural, and Environmental Engineering, Apr 1, 2024
Pervious concrete is a special type of concrete that addresses critical environmental issues and ... more Pervious concrete is a special type of concrete that addresses critical environmental issues and supports green, sustainable construction. In such concrete, little or no sand is employed in the mix in order to allow the formation of considerable void content leading to high permeability. In this study, seven pervious concrete mixes made with recycled coarse aggregate and containing different amount of natural fine aggregate are tested in the laboratory for their strength. The source of the coarse aggregate is demolished old concrete buildings in the United Arab Emirates. One of the mixes contains 100% natural coarse aggregate without natural sand, another 100% recycled coarse aggregate without natural sand, and the remaining 5 mixes include both recycled coarse aggregate and fine natural aggregate such that the amount of fine-to-coarse aggregate is 1.5-11.7%. Results of the study revealed that that the use of recycled coarse aggregate in pervious concrete without fine aggregate reduced the compressive strength by 36% and tensile strength by 57%. Replacing 4.7% of the recycled coarse aggregate with natural sand in such concrete helped in restoring the compressive strength to the level of the control mix that contained natural coarse aggregate. Likewise, replacing 11.7% of the recycled coarse aggregate with natural sand in concrete mix aided in restoring the split cylinder tensile strength to the level of the control mix that contained natural coarse aggregate. There is a relationship between compressive and tensile strengths, of which a lower bound can be reasonably predicted by models proposed for pervious concrete in the literature. The study confirms the feasibility of using recycled aggregate in pervious concrete mixes if about 10% natural fine aggregate is utilized in the mix as replacement of the recycled coarse aggregate.
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Papers by Magdi Elemam
conditions on the intensity of ground shaking of major cities in United Arab Emirates
(UAE) including Abu Dhabi, Dubai, and Sharjah, and their surrounding areas. Two time
histories for each city were chosen based on the target response spectrum that was obtained
from results of probabilistic seismic hazard analysis conducted in previous study for UAE.
Subsurface geotechnical data from more than hundred different sites were used to evaluate
the effect of local site conditions on ground response during earthquake. Dynamic properties
of soil for selected soil profiles have been generated, and one-dimensional site
response analysis has been conducted. Results are presented in terms of response spectral
accelerations (RSA) for different site classes in each city. RSA results indicated that the
surficial deposits in the studied areas have the ability to amplify earthquake ground motion
significantly with peak amplification at relatively narrow frequency range of 1.5–5 Hz
(0.2–0.67-s period). This frequency range was found to be a representative of the predominant
frequency ranges of the site classes under consideration. At higher frequencies,
slight amplification, and in some cases slight attenuation, is observed. Design response
spectra for each site class in each city were developed based on the results of site response
analysis. The developed design response spectra were compared with spectrum currently
used in each city, and the modified site coefficient is presented.
growth which is coupled with the increase in seismic activity in the surroundings.
Previous studies presents significant variations in their results whereas some recent studies
although very detailed focus on only few cities. This study reviews the results of previous
studies and presents new findings for the whole of UAE based on the improved source model
and use of next generation attenuation (NGA) equations. The peak ground accelerations,
spectral accelerations and deaggregation of hazard for major cities are presented. Moreover,
the breakdown of the range of mapped spectral accelerations (S0.2 and S1) is proposed to form
the basis for the development of site amplification factors in subsequent studies. The results
of this study indicate almost similar values of ground motion compared to some recently
published studies and smaller values compared to some earlier studies.
conditions on the intensity of ground shaking of major cities in United Arab Emirates
(UAE) including Abu Dhabi, Dubai, and Sharjah, and their surrounding areas. Two time
histories for each city were chosen based on the target response spectrum that was obtained
from results of probabilistic seismic hazard analysis conducted in previous study for UAE.
Subsurface geotechnical data from more than hundred different sites were used to evaluate
the effect of local site conditions on ground response during earthquake. Dynamic properties
of soil for selected soil profiles have been generated, and one-dimensional site
response analysis has been conducted. Results are presented in terms of response spectral
accelerations (RSA) for different site classes in each city. RSA results indicated that the
surficial deposits in the studied areas have the ability to amplify earthquake ground motion
significantly with peak amplification at relatively narrow frequency range of 1.5–5 Hz
(0.2–0.67-s period). This frequency range was found to be a representative of the predominant
frequency ranges of the site classes under consideration. At higher frequencies,
slight amplification, and in some cases slight attenuation, is observed. Design response
spectra for each site class in each city were developed based on the results of site response
analysis. The developed design response spectra were compared with spectrum currently
used in each city, and the modified site coefficient is presented.
growth which is coupled with the increase in seismic activity in the surroundings.
Previous studies presents significant variations in their results whereas some recent studies
although very detailed focus on only few cities. This study reviews the results of previous
studies and presents new findings for the whole of UAE based on the improved source model
and use of next generation attenuation (NGA) equations. The peak ground accelerations,
spectral accelerations and deaggregation of hazard for major cities are presented. Moreover,
the breakdown of the range of mapped spectral accelerations (S0.2 and S1) is proposed to form
the basis for the development of site amplification factors in subsequent studies. The results
of this study indicate almost similar values of ground motion compared to some recently
published studies and smaller values compared to some earlier studies.