لرؤية بعض المقاطع - إضغط الرابطين أدناه

 

 http://www.youtube.com/DRMALHAJ

 

http://vimeo.com/user2803847/videos

dr mohammed alhaj

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• MY SEMINAR AT DUBAI ON FEB. 1998
• my_seminar_at_AL-QASEEM_-_march_2008/
  
• MY SEMINAR AT DUBAI ON APRIL 2008
• MY SEMINAR AT KFUPM IN DAHRAN - SAUDI ARABI 2009

 

 

The summery of my papers and seminars at Dubai, Qatar, Saudi Arabia, Egypt and USA. I explained the following: 

I am trying hard to encourage Saudi Arabia and the Arabian Gulf States to adopt the American standard in the states that had similar environment (i.e. California , Nevada , Texas and Florida ), as used by their FDOT, TDOT, NDOT and CDO. Also ACI 318. Dubai municipality had the best standard in the middle east because the researcher at Dubai had adopted the specifications of FDOT, Florida, USA and Australia because it had similar environment to Dubai.

 In the last seminars and papers at Dubai, Qatar, Saudi Arabia, Egypt and USA, I explained the following:

1- The higher international cost of corrosion repair and corrosion control (NASA and NACE figures). I mentioned that the use of bad quality of Ordinary Portland cement only can lead to these problems. The corrosion and deterioration of structures can be reduced by using blended cement (i.e. Fuel Ash, Slag and Natural Pozzolana (roman concrete from volcanic ash).

 2- I discussed the summary of my PhD results and conclusion at UK on 2003.In my PhD at UK, I studied the effect of cement type and the interface on the durability and corrosion of the steel bars embedded in different cement types immersed in tidal zone of sulphate, chloride or sabkha (marine) solution.

Moreover, I measured the corrosion potentials, corrosion currents and polarization of the bars embedded in OPC (0.45), SRPC (0.45), PFA30, GGBS 70 and OPC (0.6). To compare the corrosion results with  Long-Term Durability of concrete, many cubes cast from different Cement Types were tested at 3, 7, 14, 28, 90, 200, and 800 days for Unit Weight, Pulse Velocity, Compressive Strength And Initial Absorption Test and Chloride Content. The best durability results on my PhD were from blended concrete PFA and Slag.

3- I explained the disadvantages of using Sulphate resistance. I quoted Prof Rasheeduzzafar, Prof. Omar Al-Amoudi , Prof. Adam Neville and Ted and Walker who stated that the big mistake that we had in Saudi and Gulf States   is using SRPC (Type V) cement in our marine, chloride-rich environment.

The use of Type 5 in USA is 0.5% according to PCI, USA, but in Saudi Arabia, Qatar and some Arabian Gulf States the contractores and builders in all reinforced concrete in contact with or without seawater!!!!!

 SRPC - British Standard 4027 : 1996 ‘Sulfate-resisting Portland cement’ Sulfate-resisting cement is specified in concrete for certain sulfate exposure classes as described in Irish Standard I.S. EN 206-1:2002. It stated that  (The use of SRPC is not recommended in BS 6349 Part 1 ‘Maritime structures’ for reinforced concrete in contact with seawater.) The problem that in Saudi and arbian gulf most consultants still specify SRPC (Type 5) to be used in all reinforced concrete in contact with seawater!!!!!

4- In my seminars, I explained some problems associated with using (10-16%) micro silica in hot and marine areas (i.e. Saudi and USA) with higher heat of hydration and higher plastic shrinkage cracks that lead to chloride penetration.

We had a lot of corrosion few years after using micro-silica in humid and hot marine environment in Jeddah, Saudi Arabia.

5- I had discussed in my seminars, the benefits of using natural pozzolana (ASTM c-595 type N) in projects and construction (i.e. higher durability and workability, higher slump and setting time, freedom from segregation and less bleeding, longer service life, energy saving, Co2 emission reduction, a reduction in lung cancer, heat insulation, water retention, water reduction, united nation and ALFAW approval, LEED and Green Building recognition).

6- I had presented some photos with facts from the U.S. and Saudi Arabia showing the fast failure of epoxy coated rebars embedded in concrete in hot and marine environment. I quoted Prof Alberto A. Sagüés for his grateful research on the failure of ECR.

Prof Alberto A. Sagüés, USF, TAMPA, FLORIDA, USA was the first professor who discovered the early failure of epoxy-coated bar at Florida Keys at 1996. At that time I was in my second year of my PhD at University of Surrey, UK.  I was waiting for epoxy coated bars from Allied coating to study the effect of the coating on the corrosion control.  After few months of waiting the ECR bars, Allied coated company had apologized to me, since they closed out their business. The important reason for their closure in UK was the results of Prof Alberto A. Sagüés research at USF about the above research about early failure of epoxy-coated bar at Florida Keys at 1996.

7- Finally, I showed in my seminars, a sample of Zinc coated bar or multi-coated metallic bars (DCR) as an alternative to ECR. I explained that one of the important benefits of Zinc is that it will act as a scarified anode to protect the steel.

Also I need to do more research about the benefits of zinc coated bars in Saudi Arabia and Arabian Gulf States.

Best Wishes,

 DR Mohammed Alhaj Hussein, PhD 
        
Adviser and Consultant for green cement Constructions, Projects, Corrosion control and Concrete Quality

 USA  Address :

Dr Mohammed Alhaj Hussein

Tel :  001-813-508-5350

m@dralhaj.com

www.dralahj.com

 

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الصور التالية تبين صور عينات الدكتوراه التي بدأت بفحصها ودراستها منذ عام 1995م وحتى عام 2003 م

والتي توضح سرعة تأكل حديد التسليح المدفون في خرسانة مقاومة للكبريتات مقارنة القسم الأخر من الحديد المدفون في أسمنت بورتلاندي عادي مع تعريضهما لنفس النسبة العالية من أملاح الكلور لمدة سبع سنوات 

This photo shows the forms of bonding specimen during my PhD. University of Surrey, Guildford, UK. 1997. The steel bars were embedded in one or two cement types to study the effect of specifications in Saudi Arabia that specified OPC for the reinforced concrete parts above the ground and SRPC for the the reinforced concrete parts under the ground.

C1= OPC cement

C2= SRPC or OPC type v.

 

 

This photo shows the forms of bonding specimen during my PhD. University of Surrey, Guildford, UK. 1997. The steel bars were embedded in one or two cement types to study the effect of specifications in Saudi Arabia that specified OPC for the reinforced concrete parts above the ground and SRPC for the the reinforced concrete parts under the ground.

One type of cement was cast in one part of specimen, then the same or different type of cement was cast in the following day.

C1= OPC cement

C2= SRPC or OPC type v.

 

 

This photo shows the forms of bonding specimen during my PhD. University of Surrey, Guildford, UK. 1997. The steel bars were embedded in one or two cement types to study the effect of specifications in Saudi Arabia that specified OPC for the reinforced concrete parts above the ground and SRPC for the the reinforced concrete parts under the ground.

One type of cement was cast in one part of specimen, then the same or different type of cement was cast in the following day.

C1= OPC cement (W/C=0.45) 

C2= SRPC cement OPC type v (W/C=0.45)  

B= OPC cement (W/C=0.60) 

 

All bonding specimens were exposed to splash zone (wetting and drying cycles).

The following solutions were used from 1997-2002

1- molar Na2So4 -

2- molar NaCl 

3- combnations of NaCl+Na2So4 (Sabkha solution)

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The following photos show the disadvantage of using cement (Type v = SRPC) in chloride and marine environment in Saudi Arabia.

The macro-cell corrosion was increased due to the wrong specifications in Saudi Arabia that allow the use of two different cement types with different C3A and different chemical and physical properties in the same element in the building.

The steel bar embedded in OPC cement will act as cathode and the steel bar embedded in SRPC cement will act as anode.

N.B. No corrosion in the part of steel bar that embedded in OPC cement, whilst sever corrosion can be seen at the other part of steel bar embedded in SRPC cement.

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 This photo shows bonding specimen during my PhD. University of Surrey, Guildford, UK. 2002

All bonding specimens were exposed to splash zone (wetting and drying cycles).

The macro-cell corrosion was increased due to the wrong specifications that allow the use of the same cement types with different w/c ratio in the same element in the building, that lead to different chemical and physical properties along the steel bars.

The steel bar embedded in OPC cement (w/c=0.45) will act as cathode and the steel bar embedded in OPC cement (w/c=0.60) will act as anode.

N.B. No corrosion in the part of steel bar that embedded in OPC cement (w/c=0.45), whilst sever corrosion can be seen at the other part of steel bar embedded in OPC cement (w/c=0.60) .

 

C1= OPC cement (W/C=0.45) 

B= OPC cement (W/C=0.60) 

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This photo shows bonding specimen during my PhD. University of Surrey, Guildford, UK. 2002

All bonding specimens were exposed to splash zone (wetting and drying cycles).

The macro-cell corrosion was increased due to the wrong specifications that allow the use of two different cement types even with same w/c ratio in the same element in the building, that lead to different chemical and physical properties along the steel bars.

The steel bar embedded in OPC cement (w/c=0.45) will act as cathode and the steel bar embedded in SRPC cement (w/c=0.45) will act as anode.

N.B. No corrosion in the part of steel bar that embedded in OPC cement (w/c=0.45), whilst sever corrosion can be seen at the other part of steel bar embedded in SRPC cement (w/c=0.45) .

 C1= OPC cement (W/C=0.45) 

C2= SRPC cement OPC type v (W/C=0.45)  

 

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This photo shows bonding specimen during my PhD. University of Surrey, Guildford, UK. 2002

All bonding specimens were exposed to splash zone (wetting and drying cycles).

The macro-cell corrosion was increased due to the wrong specifications that allow the use of two same cement types with different w/c ratio in the same element in the building, that lead to different chemical and physical properties along the steel bars.

The steel bar embedded in OPC cement (w/c=0.45) will act as cathode and the steel bar embedded in OPC cement (w/c=0.60) will act as anode.

N.B. No corrosion in the part of steel bar that embedded in OPC cement (w/c=0.45), whilst sever corrosion can be seen at the other part of steel bar embedded in OPC cement (w/c=0.60) .

 

C1= OPC cement (W/C=0.45) 

B= OPC cement (W/C=0.60) 

 

 

 

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 الإستشاري الدكتور المهندس محمد تاج الدين الحاج حسين بعد نجاحه في امتحان شهادة الدكتوراه في الهندسة المدنية من جامعة ساري بمدينة جيلدفورد جنوب لندن - بريطانيا- منتصف سبتمبر 2003 م

ويبدو من اليمين

1- الممتحن الخارجي البرفسور عمر سعيد باغبيرة العمودي  من جامعة الملك فهد للبترول والمعادن - الظهران - السعودية

2- الممتحن الداخلي وهو برفسور بريطاني من أصل يوناني ويعمل كرئيس لقسم الهندسة المدنية بجامعة ساري

 3- البرفسور المشرف العام على الرسالة وهو مسلم بريطاني ويعمل محاضراً بقسم الهندسة المدنية واسمه مايك ملهورن 

 4 - البرفسور المشرف الثاني على الرسالة وهو بريطاني من أصل نيجيري ويعمل محاضراً بقسم الهندسة المدنية واسمه ساني نوباني

 

 

 الإستشاري الدكتور المهندس محمد تاج الدين الحاج حسين بجانب الدكتور فيصل غرغاب بعد نجاحهما في امتحان شهادة الدكتوراه في الهندسة المدنية من جامعة ساري بمدينة جيلدفورد جنوب لندن - بريطانيا- نهاية سبتمبر 2003 م

 البرفسور عمر سعيد باغبيرة العمودي مع ولدي عاصم قبل سفره للسعودية قرب بحيرة جامعة ساري بمدينة جيلدفورد في بريطانيا

نهاية سمبتمبر 2003 م 

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 Corrosion Cost

• •        National growth and economical implications are closely related to the adequacy of the infrastructures.
• •        The total corrosion cost has been reported to cost the USA between $ 250-400 billion / year  (NASA 2003) and the UK £ 1.5 trillions / year. 
• •        The total corrosion cost include :

  Overall maintenance program for infrastructure facilities   

  and marine installations, corrosion control, training and education.

  

 

Preventative Strategies: Non-technical

• •         Increase awareness of large corrosion costs

       and potential savings.

• •         Change the misconception that nothing can be done about corrosion.
• •         Change policies, regulations, standards (Saudi Building Code that is dependent totally on ACI, USA.), and management practices to increase corrosion savings through corrosion control management
• •         Improve education and training of staff in recognition of corrosion control (NACE courses and certificates)

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Preventative Strategies: Technical

Advance design practices for better corrosion management to avoid deterioration. a number of variable options include:

• Good mix design (w/c < 0.4)
• Adequate cover to rebar (50-120 mm )
• Good site practice (Workability, Compaction, Curing 14-28 days)
• Anti-corrosion coatings : –
  1. Fusion bonded epoxy-coated rebars (failed in Florida and other US states after few years. It had been removed from UK market since 1996.

Alternative REBAR coating are been used in DOT in

USA

after failure of epoxy coated bars.

       b) Sealers or Silane for the concrete surface

• Cement Type - Blended cements (Local natural Pozzolan around Madina or SLAG a waste products from iron steel factories. Fuel ash from electricity plants in Saudi Arabia ).ALL these are used now in Worldwide depend on the availability on their areas.
• Corrosion-inhibiting admixtures and Polymer admixtures for concrete
• Alternative Reinforcements
• Cathodic Protection CP technologies
• Non-destructive monitoring techniques
• Non-corrosive Deicers in cold weather

 

 

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 Qualifications:

2003 - PhD in Corrosion and Durability of Reinforced Concrete using four different types of cements, University of Surrey , UK

1986 - BSC in Civil Engineering, King Abdul-Aziz University , Saudi Arabia

Certifications:

2008- NRMCA Environmental Management and Green Star for Ready Mix concrete, USA

2006 – FDOT Earthwork construction Inspector, USA

2006 - ACI & FDOT Concrete Laboratory Testing Inspector, USA

2006 - ACI Concrete Strength Testing Technician, USA

2006 - ACI & FDOT Concrete Field Testing Technician and Inspector, USA

2004 – NACE Corrosion Technologist, USA

2004 – NACE Corrosion Technician, USA

2004 – NACE Cathodic Protection Tester, USA

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www.almadinapress.com