Browsing by Author "Mohammed Ismail"

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Improving the performance of damaged FBECR in chloride-contaminated concrete
(Saudi Digital Library) Mohammed Ismail
ﺘﻡ ﺇﺠﺭﺍﺀ ﻫﺫﻩ ﺍﻟﺩﺭﺍﺴﺔ ﻟﺘﺤﺩﻴﺩ ﺍﺜﺭ ﺍﻟﺨﺩﻭﺵ ﻋﻠﻰ ﻁﺒﻘﺔ ﻁـﻼﺀ ﻗـﻀﺒﺎﻥ ﺤﺩﻴـﺩ ﺍﻟﺘﺴﻠﻴﺢ ﺍﻟﻤﻁﻠﻴﺔ ﺒﻤﺎﺩﺓ ﺍﻷﻴﺒﻭﻜﺴﻲ ﻋﻨﺩ ﺍﺴﺘﺨﺩﺍﻡ ﺨﺭﺴﺎﻨﺔ ﺍﺴﻤﻨﺕ ﻋﺎﺩﻱ ﻭﺨﺭﺴﺎﻨﺔ ﺍﺴﻤﻨﺕ ﻤﺨﻠﻭﻁ ﺒﻤﻭﺍﺩ ﺇﻀ ﺎﻓﻴﺔ ﻤﺜل ﺴﻠﻴﻜﺎﻓﻴﻭﻡ ، ﻓﻼﻱ ﺃﺵ ﻭ ﺒﻼﺴﺕ ﻓﺭﻨﺱ ﺴﻼﻕ . ﺃﻴﻀﺎ ﺘﻡ ﺘﺤﺩﻴﺩ ٢±٢٣) ﺍﺜﺭ ﺍﻟﺘﻌﺭﺽ ﻟﺩﺭﺠﺎﺕ ﺍﻟﺤﺭﺍﺭﺓ ﺍﻟﻤﺨﺘﻠﻔﺔ ،٣٥±٢ ٢±٤٨ ﻭ ، ﺩﺭﺠﺔ ﻤﺌﻭﻴﺔ ( ﻋﻠﻰ ﻤﻌﺩل ﺘﺂﻜل ﺍﻟﺤﺩﻴﺩ . ﺘﻤﺕ ﻤﻘﺎﺭﻨﺔ ﺍﻟﺘﺂﻜل ﻨﺘﻴﺠﺔ ﻟﺼﺩﺃ ﺍﻟﺤﺩﻴـﺩ ﻓـﻲ ﺍﻟﻘـﻀﺒﺎﻥ ﺍﻟﻤﻁﻠﻴـﺔ ﻭﻤﻘﺎﺭﻨﺔ ﺒﺎﻟﺘﺂﻜل ﻓﻲ ﺍﻟﻘﻀﺒﺎﻥ ﺍﻟﻐﻴﺭ ﻤﻁﻠﻴﺔ ﺒﻭﺍﺴﻁﺔ ﻗﻴﺎﺱ ﺸ ﺩﺓ ﺍﻟﺠﻬﺩ ﺍﻟﻜﻬﺭﺒﺎﺌ ﻲ ﻟﻠﺘﻴـﺎﺭ ﺍﻟﻨﺎﺘﺞ ﻋﻥ ﺍﻟﺼﺩﺃ ﻭﺃﻴﻀﺎ ﺸﺩﺓ ﺍﻟﺘﻴﺎﺭ ﺍﻟﻜﻬﺭﺒﺎﺌ ﻲ ﺨﻼل ﻓﺘﺭﺍﺕ ﺯﻤﻨﻴﺔ ﻤﻨﺘﻅﻤﺔ . ﺃﻅﻬـﺭﺕ ﻨﺘﺎﺌﺞ ﻗﻴﺎﺱ ﺸﺩﺓ ﺍﻟﺘﻴﺎﺭ ﺍﻥ ﺍﻟﻘﻀﺒﺎﻥ ﺍﻟﺘﻲ ﻟﻡ ﺘﺘﻌﺭﺽ ﻟﺨﺩﻭﺵ ﻓﻲ ﺴﻁﺢ ﺍﻟﻁﻼﺀ ﻜ ﺎﻨـﺕ %٢ ﺨﺎﻤﻠﺔ ﻓﻲ ﻜل ﺒﻴﺌﺎﺕ ﺍﻟﻜﻠﻭﺭ ﺤﺘﻰ ﻨﺴﺒﺔ ﺘﺭﻜﻴﺯ ﻭ ٤٨ ﺘﻌﺭﻴﻀﻬﺎ ﻟﺩﺭﺠـﺔ ﺤـﺭﺍﺭﺓ ﺩﺭﺠﺔ ﻤﺌﻭﻴﺔ .ﺒﻴﻤﻨ ﺎ ﻭﺠﺩ ﺇﻥ ﺍﻟﺼﺩﺃ ﻓﻲ ﺍﻟﻘﻀﺒﺎﻥ ﺍﻟﺘﻲ ﺘﻌﺭﻀﺕ ﻟﺨﺩﻭﺵ ﻓﻲ ﺍﻟﻁﻼﺀ ﻴﺯﻴﺩ ﺒﺯﻴﺎﺩﺓ ﻜﻤﻴﺔ ﺍﻟﺨﺩﻭﺵ ﻭ ﺩﺭﺠﺔ ﺍﻟﺤﺭﺍﺭﺓ ﻭﺘﺭﻜﻴﺯ ﺍﻟﻜﻠﻭﺭ ﻓﻲ ﺍﻟﻌﻴﻨﺔ . ﻭﻗـﺩ ﻭﺠـﺩ ﺇﻥ ﺃﺩﺍﺀ ﺍﻟﻘﻀﺒﺎﻥ ﺍﻟﻤﻁﻠﻴﺔ ﺒﺎﻷﻴﺒﻭﻜﺴﻲ ٤٨ ﻜﺎﻥ ﻤﺭﻀﻲ ﻓﻲ ﺩﺭﺠﺔ ﺍﻟﺤﺭﺍﺭﺓ ﺩﺭﺠﺔ ﻤﺌﻭﻴﺔ ﻭﺤﺘـﻰ %ﺍﻟﺨﺭﺴﺎﻨﺔ ٢ ﻨﺴﺒﺔ ﺘﺭﻜﻴﺯ ﻤﻥ ﺍﻟﻜﻠﻭﺭ ﻓﻲ ﺨﻠﻁﺔ .
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Improving the performance of damaged FBECR in chloride-contaminated concrete
(Saudi Digital Library) Mohammed Ismail
This study was conducted to evaluate the effect of surface damage on corrosion resistance of fusion bonded epoxy coated (FBEC) steel bars cast in plain and blended cement concretes. The effect of exposure temperature (23±2, 35±2 and 48±2) on the rate of corrosion was also evaluated. The effect of these parameters on the corrosion of FBEC bars was compared with the corrosion of mild steel bars by exposing the concrete specimens prepared with them and measuring corrosion potentials and corrosion current density at regular intervals. The corrosion current density measurements indicated that the defect-free FBEC bars were in a passive condition in all blended cements concrete specimens with up to 2% chloride, by weight of cement, even when they were exposed to 48. The corrosion current density in concrete specimen with black and damaged FBEC steel bars increased with an increase in the exposure temperature and the chloride contamination. The long-term performance of FBEC steel bars exposed to 48 was satisfactory in the silica fume cement concrete specimens admixed with up to 2% chloride, by weight of cement.
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