Topic Highlights Building / Construction Materials Rebar Manufacturing Process Environmental Aspects

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

Resources