1. Study on Practicability Assessment of Asphalt Concrete With BOF SLAG Speaker:Fang-Chih Chang Department of Civil Engineering National Central University Chung-Li,Taiwan Republic of China May 10,2000

2. Contents zIntroduction zExperimental Design and Experimental Program zTest Results and Analysis zConclusion

3. Introduction(1/2) zEnvironmental Protection zThe Residual Products of Industry zDisposal and Recycling zThe Lack of Natural Aggregate zMillions of Tons of Slag each year

4. Introduction(2/2) zHigh Temperate zHumidity zGround Water Levels zAutomobiles and Heavy Truck zAim : Improve the Destruction of Structure z Provide a Substitute for Natural Gravel

5. Experimental Design and Experimental Program zEXPERIMENTAL DESIGN zEXPERIMENTAL PROGRAM

6. Experimental Design zEvaluate the Feasibility of BOF Slag in Substitute for Natural Gravel zMarshall Test Machine 、 Superpave Gyration Compactor(SGC) and Cantabrian Test zLong-term Behavior of BOF Slag Asphalt Concrete

7. Experimental Program zAggregate zAsphalt zTest Flow Chart

8. Aggregate zBOF Slag--China Hi-Ment Corporation zNatural Gravel--Stream zIn Marshall test, one gradation was selected, a Taiwan Highway Bureau, typical of a dense graded aggregate, having a 3/4 in., maximum size. zIn SHRP, we used the graded aggregate of Superpave, having a 3/4 in., maximum size.

9. 4C Dense Graded Curve

10. Asphalt zAsphalt cement with a viscosity grade of AC- 20, which is a product of the China Petroleum Company, was selected for use in this study. TestTest ResultSpecification Penetration (25 ℃， 0.1mm) 6260-70 135 ℃ Viscosity (poises) 3.86— 60 ℃ Viscosity (poises) 22432000±400 Softening point ( ℃ ) 48.4— Ductility (cm) 100 以上 —

11. Test Flow Chart(1/2) Basic Properties tests: Penetration, Viscosity, Softening point, Ductility test Selected gradation Basic Properties: Mineralogical characteristics, Specific gravity, Soundness Los Angeles abrasion test Asphalt Concrete Mixtures AsphaltGravel

12. Test Flow Chart(2/2) Asphalt Concrete Mixtures Marshall MixtureSHRPOGFCCantabrian Resilient modulus Indirect tensile strength Rutting Water sensitivity test Stripping test Residual stability value Resilient modulus Indirect tensile strength Permeable test Durability test Skidding test Permeable test Skidding test

13. Test Results and Analysis zPhysical Properties Tests zPerformance Properties Tests

14. Physical Properties Tests

15. Basic Physical Properties Tests *According to ASTM

16. The Petrographic Examination of Gravel According to ASTM C295-90

17. Performance Properties Tests z Marshall stability test z The Gradation of SHRP z Drainage Pavement Test

18. Marshall Stability Test zAI MS-2 mixture design method z4C dense-graded of the Taiwan Highway Bureau zMarshall stability test zThe Sensitivity of Water, Specimens with water,60 ℃, 24 hours

19. The Results of Marshall Stability

20. The Gradation of SHRP zIt will be better by using the below gradation of restriction zone, in order to avoid resulting the gradation of frailness(Tender Mix). zWe attempted to find the gradation which was fit for natural gravel (N), BOF (B), and partial BOF (BN).

21. The Curve of Attempted Gradation of SHRP

22. SHRP Performance zThe test of residual strength of indirect tensile is according to ASTM D4867. zRutting test was carried out in the temperature of 60 ℃ which was imitative the pavement in summer.

23. Residual Strength of Indirect Tensile before water and after water

24. The Result of Rutting Test In 60 ℃

25. Drainage Pavement Test(1/2) zInadequate surface drainage is frequently a primary cause of the pavement distresses that necessitate reconstruction. zOGFC and PA -- a large number of voids and a large percentage of coarse aggregate zInfluence the Safety and Vision of the movement of vehicles.

26. Drainage Pavement Test(2/2) zPerformance of PA concrete pavement with BOF Slag zAging --cause loss of the flexibility of pavement zAging -- increases the ability of displacement resistance.

27. The Results of Indirect Tensile in 25 ℃

28. The Air Void of PA

29. The Permeable Coefficient of PA

30. Conclusion zHigher percentage of calcia (CaO) in BOF composition can increase the glue between aggregate and asphalt binder and thus reduce the phenomenon of stripping. zThe performance of BOF slag is better than natural gravel in asphalt concrete.

31. Conclusion zBOF slag can be utilized in paving construction, it can not only save the cost of paving materials and maintenance, but reduce the destruction of industrial by-product to environment and fill the bill of sustainable development.

32. Suggestion zIn the follow-up research, it is important to pay attention to the effect of expansion in BOF. zWe will proceed the research of using BOF in base and Subbase with fly ash. zWe must take account of the entire economical cost when we use BOF slag in asphalt concrete.

33. THE END  Thanks Ping-Chuan Lin and Tung-Yuan Chang of China Hi-Ment Corporation for providing help of the research. Thanks for your attention!