Post on 17-Jan-2016
transcript
Topic Highlights
Building / Construction Materials
Rebar
Manufacturing Process
Environmental Aspects
• Stainless Steel Rebar
• Fiber Reinforced Polymer
• Carbon Steel Rebar
Rebar Materials
Rebar Materials
• Stainless Steel Rebar– Excellence corrosion resistance;– well known properties; widely used in
marine & corrosive environments;– Well developed standards;– Very high initial costs $;– Critical structure only;
Rebar Materials• Fiber Reinforced Polymer FRP
– Impervious to chloride ion and chemical attack;• Good for aqueous environments;• E.g. salt storage facilities, bridge decks, floating mar
ine dock…
– Nonmetallic properties Transparent to magnetic fields and radio frequencies;
• E.g. Hospital MRI rooms, compass calibration pads, high V cable concrete…
– Higher TS than steel can be archived;– ¼ wt of steel reinforcement;– Carbon FRP, Glass FRP, Aramid FRP are ava
ilable;
FRP Barriers
• Lack of well established standards• Mechanical properties and bond
characteristic;• Manufacturing standards
– Type & volume of fiber and resin;– Fiber orientation;– QC standards;
• NO in-site fabrications are allowed– E.g. bending, welding..
Carbon Steel Rebar• Carbon Steel Rebar
– Well known properties and well developed standards;– Widely used in various environments;– Widely used in various specifications;
• e.g. epoxy coating, galvanizing, perstressed…etc.
– Easy manufacturing and market availability;– Low costs $;
• Low Carbon Steel Rebar C <0.25%
Low Carbon Steel Rebar• HK Standard: CS2:1995
– Frame on BS4449:1988;– Tensile Strength 460 N/mm2;
• Standards Developments:– BS4449:2005 ; Grade B500; – Macau 第 64/96/M 號法令 ; Grade 500;– GB 1499-1998 ; HRB335 & HRB400, rare in HRB500; (under drafting of GB1499.2-XXXX version)– CS is under reviewing;
• Manufacturing process, Regional based:– Hot roll bar:
• V, Nb alloying high cost;• No further thermal processing required, natural air cooling;• e.g. Japan, USA, China
– Quenched bar:• Low alloying elements, No V, Nb lower cost;• Water quenching and tempering required;• e.g. Europe, Turkey, South Asia, China
• Blast Furnace Route– Iron ore– High Energy consumptions– More pollutants
• Electric Arc Furnace EAF Route– Scrap– Relatively low energy consumptions– Steam line process– 100% recycle of Scraps– Compact in size
Steel Manufacturing Route
Blast Furnace Route
•Iron Ore
•Coke
•Small amount of Scrap
Electrical Arc Furnace EAF Route
•Scrap
Basic Oxygen Furnace BOF
Ladle Furnace
Casting m/c
Steel Making Route
Rolling Operations
Reheating Furnace EBROS Rolling Quenching
Cooling Bed
ShearBars
Cold Charging From Billet stock
Hot Charging from CCM
Tuen Mun Mill Operations
RHF EBROS Rolling QuenchingCooling Bed
ShearBars
Electricity Consumption
Cooling Water
Scrapped bars
Fuel Consumption
Environmental Aspects• Resource Recycling
– Scrap for Electric Arc Furnace– Sewage treatment system
• Conserving natural resources– Water treatment plant– Reduce electricity demand
• Protecting marine environment– Marine Pollution Equipment
• Minimizing waste– EBROS – minimize wastage
Cooling Water Treatment Plant
• Operations involved Direct water cooling;• Operations involved Indirect water cooli
ng;• In house treatment plant 100% servic
e water recycling;• No discharge of service water to environ
ments; • 1998 in Operations
Cooling Water Treatment System
Machineries /Equipments
Chemical Treatments
Storage tanks
Sand Filters
SettlementDegreasing
Sea Water
Plate Type Heat Exchangers
Minimized Scrap Rolling• Innovative operation of Endless Bar Rolling S
ystem EBROS;• Infinitive long billets rolling = no excessive cu
tting materials;• Exact Multiple of Finishing Length;• Rolling process save head and tail cuts , abo
ut -4% of rolling material;• Perform cut-to-length orders; Reduce civil site cutting scraps• 2001 in Operations
Endless Bar ROlling System
Welding Stage
Welded Joint
Deburred & Rolled Joint
D.C. 9 V
12000 Amp
Endless Bar ROlling System
Discontinuous-Conical elongation of the Joint NO weak point in finishing material !
Rolling Direction
Endless Bar ROlling System
Exact multiple length
Minimized Scrap
Save you fabrication time !
Save your material cost !
Save $
• THANK YOU !
Environments Developments
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