Effects of Ground Granulated Blast Furnace Slag in Portland Cement ...

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CEMENTC 6000 ength, psi Compressive Str 5000 4000 3000 2000 C.0.L C.30.L C.50.L C.0.I C.30.I C.50.I 1000 2 3 4 5 6 7 8 10 1 2 3 4 5 6 7 8 10 2 2 3 4 5 Age, days Figure 10. Compressive strength trend line for specimens using cement C (Key: cement type, GGBFS %, aggregate type (L= limestone, I = igneous) CEMENTD 8000 Compressive Strength, psi 6000 4000 2000 D.0.L D. 30. L D. 50. L D.0.I D.30.I D. 50.I 0 2 3 4 5 6 7 8 10 1 2 3 4 5 6 7 8 10 2 2 3 4 5 Age, days Figure 11. Compressive strength trend line for specimens using cement D (Key: cement type, GGBFS %, aggregate type (L= limestone, I = igneous) 19
Table 12. Average compressive strength for all cement and aggregate types Compressive Stre ngth Test 0% 30% 50% Day GGBFS GGBFS GGBFS 3 3036 2290 1690 7 3579 2931 2579 14 4038 3552 3445 28 4400 4159 4047 56 4713 4514 4477 365 5428 5226 5072 The rate of strength g ain is important becau se it strongly influ ences the delay between completion of paving and road opening. WisDOT requires a compressive strength of 3000 psi to open to traffic (DOT 2004). Table 13 shows by age when the mixes would reach the standard of 3000 psi assuming laboratory curing conditions. In approximately 3 days, OPC will reach 3000 psi providing confirmation of provision 415.3.17.1 of the WisDOT Construction Specification. For A-S mix designs, WisDOT requires 7 days before opening to traffic. Table 13 reveals an average of 7-8 days to reach 3000 psi for 30% GGBFS levels but with certain cement brands the strength development may be slower. GGBFS usage at 50% generally requires 10 to 11 days on average to reach 3000 psi but again with certain cements the time required exceeded 2 weeks. The current 7-day requirement in WisDOT Construction Specification 415.3.17.1 is insufficient for 50% levels of GGBFS but it is important to note all of these results are based on w/cm = 0.45. WisDOT Construction Specification provision 415.3.17.1 uses a 0.6 factor for curing days at 40°F. This would translate to 5 days of required curing for OPC. Table 12 suggests that 11 to 18 days are required for strength to reach 3000 psi. For Grade A-S mixes the 40 degree curing temperature would dictate 12 days of curing but Table 13 suggests that 20 to 49 days is required to reach 3000 psi depending on GGBFS level and aggregate type. Table 14 confirms the late strength gain characteristics of GGBFS. After 3 days all the GGBFS concretes had less than 95% of the ordinary concrete strength. However, only three cases of less than 95% strength existed after 56 days. The averaged compressive data for each mix can be found in Appendix VI. 5.5 Deicer Scaling Resistance Test Results ASTM C672 stipulates that a visual rating of the scaling blocks be made every 5 cycles to determine the effect of deicing agents. The visual rating is a subjective measure with a scale of 0 to 5. This prompted development of a procedure that weighed the scaled material washed from the block surface to give an objective measure of the deicing chemical effects. Recall that 2 different cements were used with 3 different cement replacement levels with 2 different aggregates and 4 different curing regimes. Tables 15 and 16 list the actual levels of wash-off scaling material after 50 and 100 cycles of freeze-thaw exposure respectively. As 20
Page 1 and 2: Wisconsin Highway Research Program
Page 3 and 4: Acknowledgments The authors gratefu
Page 5 and 6: Executive Summary Project Summary G
Page 7 and 8: cement brands. The mix proportions
Page 9 and 10: Table of Contents Acknowledgements
Page 11 and 12: agree that GGBFS will result in hig
Page 13 and 14: Table 3. Test Matrix for Deicer Sca
Page 15 and 16: The batches in both phases were pre
Page 17 and 18: The second alteration to ASTM C672
Page 19 and 20: commercial laboratory for particle
Page 21 and 22: 140.0 120.0 Activity Index 100.0 80
Page 23 and 24: Table 8. ASTM C989 Reference Cement
Page 25 and 26: Table 11. Composition of the Deicer
Page 27: CEMENTA 6000 Compressive Strength,
Page 31 and 32: Table 14. Compressive Strength as a
Page 33 and 34: Influence of Curing Method on Deice
Page 35 and 36: washoff50L Washoff (g/sq m) A.50.L.
Page 37 and 38: approximately 25% to 30% correspond
Page 39 and 40: Table 17. 56-Day Shrinkage for Ceme
Page 41 and 42: strengthave C ompre ssiv e St reng
Page 43 and 44: APPENDIX I - BIBLIOGRAPHY ACI Commi
Page 45 and 46: Miura, Takashi, and Ichiro Iwaki.
Page 47 and 48: APPENDIX II - SYNTHESIS OF BIBLIOGR
Page 49 and 50: Autogenous shrinkage increa sed as
Page 51 and 52: APPENDIX III - AGGREGATE GRADATIONS
Page 53 and 54: Table IV. 2 Portland Cement Chemica
Page 55 and 56: Interview 1 on July 1, 2002 with Mi
Page 57 and 58: • The Wabasha Bridge in St Paul i
Page 59 and 60: Table VI. 2 Air Unadjusted Compress
Page 61 and 62: VII.1 VISUAL RATINGS APPENDI X VII
Page 63 and 64: M6 Cement C, 3 Block Average # Cycl
Page 65 and 66: VII.3 WASH OFF DATA 3 Block Average
Page 67 and 68: 3 Block Average Washoff - M6 Cement
Page 69 and 70: 3 Block Average Washoff - M2 Cement
Page 71: 3 Block Average Washoff - M6 Cement

Effects of Ground Granulated Blast Furnace Slag in Portland Cement ...

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