Development of PosMent

Transcription

1 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 POSCO Environment & By-Product Group 0/9

2 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) POSCO H-Steel Import CAGR 4 % Seoul POSCO H-Steel POSCO `11 `12 `13 `14 `15 `16(E) `17(E) `20 GBFS production will be increased based on steel production plan * GBFS : Granulated Blast Furnace Slag Source: Korea Cement Association, POSCO 1/9

3 2. Blast Furnace Slag Utilization Most of BFS is used as cementitious materials in Korea < BFS Utilization in Korea, 2015 > < Field Application > Civil use 10.4% Fertilizer 2.1% Road base 1.9% Etc. 0.9% Air-cooled 14.0% Granulated 86.0% Slag cement Concrete aggregate Fertilizer Embankment Cement or Powder 84.7% Asphalt concrete Anti-slip aggregate Source: Korea Iron & Steel Association 2/9

4 3. Development of PosMent The slag-rich & high-function slag cement Background - driven by the need of human society to reduce the CO 2 emissions Slag Cement Status Strength Lower CO 2 emission by utilizing GBFS in cement which typically contains 40% Offer high ultimate strength, good resistance to chemical attack Weakness Relatively lower early-age compressive strength and higher amount of drying shrinkage in comparison to Ordinary Portland Cement(OPC) 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% Cement Slag Alkali-activator (utilizing steelmaking slag) Ordinary Portland Cement 95% Slag Cement 60% PosMent 40% 40% 5% 55% 5% Max < Raw materials depending on the type of cement > 3/9

5 3. Development of PosMent Mechanism - the alkali-activator is mainly composed of Ca(OH) 2, CaO Al 2 O 3 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 < Formation of ettringite during the hydration of PosMent > Solution Anhydrite SO 2- OH - OH - 4 Ca 2+ Ca 2+ OH - Al 3+ Ca 2+ Al 3+ Free lime C 3 A / C 12 A 7 Ca 2+ Anhydrite Solution AFt(ettringite) Free lime C 3 A / C 12 A 7 Benefit * 3CaO Al 2 O 3 + 3CaSO 4 2H 2 O + 26H 2 O 3CaO Al 2 O 3 3CaSO 4 32H 2 O (ettringite) - 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

6 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) 30% 5/9

7 3. Development of PosMent Supply System By-product Activator manufactory Alkali activator Slag cement manufactory PosMent Ready-Mixed Concrete factory GBFS Future Plan - commercial scale expansion Year PosMent manufacture company Seoul E (Stage 1) +2 (Stage 2) - make up for the weak points *decrease shrinkage, reduce hydration heat, increase early strength etc. 6/9

8 4. Field Application of PosMent Residential Building Construction Features Bird's-eye view Area Floor/ Height Building: 36,000m 2 Gross Floor: 662,000m 2 Landmark Tower (101F, 412m) Residential Tower (A: 85F, 340m, B: 85F, 333m) Basement 5F Seoul Busan Completion 2020 (` ) (` ) 7/9

9 4. Field Application of PosMent Residential Building Construction Seoul Incheon Busan < Incheon Song-Do Greenwork, `12 > < Incheon Masterwiew, `12 > < Busan Centum foret, `13 > 8/9

10 4. Field Application of PosMent Non-Residential Construction Gwangyang Seoul Pohang Busan < Gwangyang SNG Silo, `12 > < Pohang Light Source,`12 > < Busan Nulcha Bridge,`14 > < East-Sea Fish Banks,`14 > < Gwangyang Harbor Caisson, `13 > < Seoul Ring Expressway, `14 > 9/9

11 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 (cm 2 /g) 4,000 ~ 6,000 6,000 ~ 8,000 8,000 ~ 10,000 7 d 55 min. 75 min. 95 min. Slag Activity 28 d 75 min. 95 min. 105 min. Index, (%) 91 d 95 min. 105 min. 105 min. Flow value ratio (%) 95 min. 95 min. 90 min. MgO (%) 10.0 max. SO 3 (%) 4.0 max. Ignition loss (%) 3.0 max. Chloride ion (%) 0.02 max. Quality of Slag Cement (KS L 5210) Class 1 Class 2 Class 3 GGBFS content (%) 5~30 30~60 60~70 SO 3 (%) 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 (cm 2 /g) 3,000 min. 3,000 min. 3,300 min. Stability Autoclave (%) 0.2 max. 0.2 max. 0.2 max. Le chatelier ( mm ) 10 max. 10 max. 10 max. Setting Initial setting (min) 45 min. 60 min. 60 min. Final setting (hr) 7 max. 10 max. 10 max. Compressive strength (N/mm 2 ) 3 d 12.5 min min. 7.5 min. 7 d 22.5 min min min. 28 d 42.5 min min min. Back Attachment 1/1