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

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washoff30i Washoff (g/sq m) 1500 1000 A.30.I.WET A.30.I.DRY A.30.I.WAX A.30.I.RESIN C.30.I.WET C.30.I.DRY C.30.I.WAX C.30.I.RESIN 500 0 0 20 40 60 80 100 cycle Figure 13. Washoff quantities with 30% GGBFS and igneous coarse aggregate subject to different curing regimes. Curing methods had a pronounced effect with the 50% GGBFS concretes (Fig 14 and Table 15). Air dry curing was the most effective method to minimize scaling and surprisingly wet curing provided the least protection. As Fig. 14 illustrates, the curing method became more important as replacement level increased, which was also found by Afrani and Rogers (Afrani & Rogers 1994). The deicer scaling performance of GGBFS concretes depended significantly on the combination of the replacement level, aggregate type, cement type and the type of curing. By most standards, GGBFS concrete scaling became unacceptable regardless of conditions at the 50% replacement level. It is apparent that the mechanism that provides a surface resistant to scaling is fundamentally different for GGBFS concrete. 25
washoff50L Washoff (g/sq m) A.50.L.WET A.50.L.DRY A.50.L.WAX A.50.L.RESIN C.50.L.WET 2500 C.50.L.DRY C.50.L.WAX C.50.L.RESIN 2000 1500 1000 500 0 0 20 40 60 80 100 cycle Figure 14. Washoff quantities with 50% GGBFS and igneous coarse aggregate subject to different curing regimes. Influence of Replacement Level on Deicer Scaling Resistance As GGBFS replacement rises so does the severity of scaling (Fig. 15, Tables 15 and 16). This held true across different aggregates, curing methods, and cements. At 30% GGBFS usage, scaling was 3 to 6 times greater than OPC scaling when limestone aggregates were used and approximately 2 times greater than OPC scaling when igneous aggregates were used. At 50% replacement, scaling was 7 to 20 times that of OPC concrete with limestone aggregates and 3 to 6 times that of OPC with igneous aggregates. Many curves of the GGBFS concretes showed an initial period (0 to 10 cycles) of little scaling followed by a high rate of scaling and then the curves settled into a rate that resembled the ordinary portland concretes. This trend is most visible at the 50% replacement level and seems to depend upon use of GGBFS because it did not occur with most of the 0% mixes. The scaling phenomenon of the GGBFS mixes has been addressed by Stark and Ludwig. They also showed that GGBFS concrete had a high rate of scaling followed by a break point in which the scaling became similar to that of ordinary concrete. They hypothesized that the heavy initial scaling was caused by carbonation of the concrete surface during initial curing. The calcium carbonate in the outer surface was dissolved by the action of the frost and chloride of the deicer salt which causes the scaling. After the carbonated layer is dissolved, the high rate of scaling subsides. SEM tests support this hypothesis (Stark 26
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 and 28: CEMENTA 6000 Compressive Strength,
Page 29 and 30: Table 12. Average compressive stren
Page 31 and 32: Table 14. Compressive Strength as a
Page 33: Influence of Curing Method on Deice
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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