Development of PosMent(A Type of Slag-rich Cement)

1. Cement Consumption & GBFS Production in Korea

2. Blast Furnace Slag Utilization

3. Development of PosMent

- Background, Concept, Mechanism, Benefits, Performances, Supply system & Future plan

4. Field Application of PosMent

- Residential Building & Non-residential Construction

Attachment : Korean Industrial Standard

2016. 11. 15

POSCO Environment & By-Product Group0/9

1. Cement Consumption & GBFS Production

Cement Consumption in Korea reached 49 Mt in 2015

but is forecasted to decrease at more than 10.0% until 2020

Cement

Consumption

(in M tons)

GBFS

Production

(in M tons)

44.6

10.0

`11

6.7

2.1

1.2

43.9

11.5

`12

8.0

2.4

1.1

45.2

12.2

`13

8.8

2.7

0.7

43.7

13.9

`14

9.0

3.8

1.1

49.1

14.8

`15

9.8

3.8

1.2

48.1

14.9

`16(E)

9.9

3.9

1.1

43.7

15.4

`17(E)

10.7

3.9

0.8

`20

Source: Korea Cement Association, POSCO

CAGR 4 %

POSCOH-SteelImport

* GBFS : Granulated Blast Furnace Slag

POSCO

Seoul

POSCO

H-Steel

※ GBFS production will be increased based on steel production plan

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2. Blast Furnace Slag Utilization

Most of BFS is used as cementitious materials in Korea

Source: Korea Iron & Steel Association

Cement or Powder84.7%

Fertilizer2.1%

Civil use10.4%

Road base1.9%

Etc.0.9%

86.0%

14.0%

Air-cooled

Granulated

< BFS Utilization in Korea, 2015 >

2/9

Slag cement Fertilizer

Concrete aggregate

Asphalt concrete Anti-slip aggregate

< Field Application >

Embankment

3. Development of PosMent

The slag-rich & high-function slag cement

■ Background

- driven by the need of human society to reduce the CO2 emissions

■ Concept

- the alkali-activator primarily manufactured by steelmaking slag has been adopted

- by adding a small amount of it, the slag content in cement is increased up to 55 wt%

Slag Cement Status

Strength • Lower CO2 emission by utilizing GBFS in cement which typically contains 40%

Weakness •Relatively lower early-age compressive strength and higher amount of drying shrinkage in comparison to Ordinary Portland Cement(OPC)

•Offer high ultimate strength, good resistance to chemical attack

5%MaxOrdinary Portland Cement

40%Slag Cement

55%PosMent

95%

60%

40%

Cement Slag Alkali-activator (utilizing steelmaking slag)

5%

< Raw materials depending

on the type of cement >

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3. Development of PosMent

■ Mechanism

- the alkali-activator is mainly composed of Ca(OH)2, CaO∙Al2O3 compound and anhydrite

- this composite creates ettringite hydrate, which increases early strength of concrete during hydration of PosMent

- the formation of ettringite hydrate in concrete structure acts as an expansive additive and decreases drying shrinkage of concrete

Anhydrite

Free lime C3A / C12A7

Ca2+

SO42-

Ca2+

Al3+Ca2+

Ca2+

OH-

OH-

OH-Solution

Al3+

Anhydrite

Free lime C3A / C12A7

Solution

AFt(ettringite)

< Formation of ettringite during the hydration of PosMent >

■ Benefit

- found the profitable way to reuse of steelmaking slag as an alkali-activator (up to 5% to cement)

- accelerate early-age compressive strength of concrete (similar to OPC)

- reduce drying shrinkage crack (around 30% vs. slag cement)

- reduce carbon dioxide emissions (around 60% vs. OPC)

4/9

* 3CaO∙Al2O3 + 3CaSO4∙2H2O + 26H2O 3CaO∙Al2O3∙3CaSO4∙32H2O (ettringite)

3. Development of PosMent

■ Performance

- early-age compressive strengths in the range from 11.0 to 12.9 MPa were obtained at 3 days depending on the application of slag concentration (similar to OPC or slag cement)

*activator increases the rate of early cement hydration so that the cement sets faster

- exhibits significantly lower drying shrinkage crack than conventional slag cement by ettringite creation and expansion effect (less than 30% of slag cement)

5/9

30%

3. Development of PosMent

■ Supply System

Alkali activatorBy-product

PosMentReady-Mixed

Concrete factory

GBFS

Activator manufactorySlag cement manufactory

■ Future Plan

- commercial scale expansion

- make up for the weak points*decrease shrinkage, reduce hydration heat,

increase early strength etc.

2016 4

2016.E

+2 (Stage 2)2017

+2 (Stage 1)

PosMent manufacture companyYearSeoul

6/9

4. Field Application of PosMent

■ Residential Building Construction

Features Bird's-eye view

AreaBuilding: 36,000m2

Gross Floor: 662,000m2

Floor/

Height

Landmark Tower (101F, 412m)

Residential Tower

(A: 85F, 340m, B: 85F, 333m)

Basement 5F

Completion 2020

(`15.12.10)(`15.12.9)

7/9

Seoul

Busan

Incheon

Seoul

Busan

< IncheonSong-Do Greenwork, ̀ 12 > < Incheon Masterwiew, `12 > < Busan Centum foret, `13 >

8/9

4. Field Application of PosMent

■ Residential Building Construction

Gwangyang

Seoul

Pohang

< Gwangyang SNG Silo, `12 > < Pohang Light Source ,`12 > < Busan Nulcha Bridge ,`14 >

Busan

< East-Sea Fish Banks ,`14 >

< Gwangyang Harbor Caisson, `13 > < Seoul Ring Expressway, `14 >

9/9

4. Field Application of PosMent

■ Non-Residential Construction

☞Back

Attachment 1/1

Attachment. Korean industrial standard

■ Quality of Ground Granulated Blast-furnace Slag (KS F 2563)

Class 3 Class 2 Class 1

Specific gravity 2.8 min.

Surface area (cm2/g) 4,000 ~ 6,000 6,000 ~ 8,000 8,000 ~ 10,000

Slag Activity Index, (%)

7 d 55 min. 75 min. 95 min.

28 d 75 min. 95 min. 105 min.

91 d 95 min. 105 min. 105 min.

Flow value ratio (%) 95 min. 95 min. 90 min.

MgO (%) 10.0 max.

SO3 (%) 4.0 max.

Ignition loss (%) 3.0 max.

Chloride ion (%) 0.02 max.

Class 1 Class 2 Class 3

GGBFS content (%) 5~30 30~60 60~70

SO3 (%) 3.0 max. 4.0 max. 4.5 max.

MgO (%) 5.0 max. 6.0 max. 6.0 max.

Ignition loss (%) 3.0 max. 3.0 max. 3.0 max.

Surface area (cm2/g) 3,000 min. 3,000 min. 3,300 min.

StabilityAutoclave (%) 0.2 max. 0.2 max. 0.2 max.

Le chatelier (㎜) 10 max. 10 max. 10 max.

SettingInitial setting (min) 45 min. 60 min. 60 min.

Final setting (hr) 7 max. 10 max. 10 max.

Compressive strength(N/mm2)

3 d 12.5 min. 10.0 min. 7.5 min.

7 d 22.5 min. 17.5 min. 15.0 min.

28 d 42.5 min. 42.5 min. 40.0 min.

■ Quality of Slag Cement (KS L 5210)