Self-consolidating concrete in congested sections: Mixture characteristics and assessment of performance

摘要

>Eight planar 6-in.-thick ?— 6-ft-deep ?— 6-ft-wide (150 mm ?— 1.8 m ?— 1.8 m) wall sections and eight 13-ft- long (4.0 m) bulb-tee (BT-72) beam sections, all with highly congested reinforcement, were fabricated in two precast concrete plants using self-consolidating concrete (SCC). The compressive strengths of cores, taken at different locations on each of the walls and beams, were compared to determine whether proper- ties varied with location. Also, the specimens were cut vertically at different locations to assess segregation of the SCC throughout the depth and length of the elements. Analysis included the use of digital image analysis. While conventional SCC testing by slump flow, U-flow, and L-box methods suggested that most of the mixtures were of good quality, this research showed that such test methods were not sufficient for predicting a mixturea€?s performance in congested sections. Only construction of mock-up sections showed the true self-consolidating performance in congested sections.>References>1. Do, Nam, Blake Stanton, and W. Micah Hale. 2006. High Strength SCC Mixtures for Prestressed Bridge Girders. In Proceedings PCI National Bridge Conference, Grapevine, TX, October 2006.  CD-ROM. >2. Burgueno, Rigoberto, and David Bendert. 2006. Experimental Evaluation and Field-Monitoring of Self-Compacting Concrete Prestressed Box Beams for Demonstration Bridge. In Proceedings PCI  National Bridge Conference, Grapevine, TX, October 2006.  CD-ROM.>3. American Concrete Institute (ACI) Committee 237.2007. Self-Consolidating Concrete. ACI 237R-07. Farmington Hills, MI: ACI. >4. Hughes, D. G., G. F. Knight, and E. F. Manski. 2002. Self-Consolidating Concrete: Case Studies Show Benefits to Precast Concrete Producers. In First North American Conference on the Design and  Use of Self- Consolidating Concrete, pp. 361-366. Chicago, IL: Hanley-Wood LLC. >5. Hughes, J. J. 2002. Evaluation of Self-Consolidating Concrete Summary Report. In First North American Conference on the Design and Use of Self-Consolidating  Concrete, pp. 259-265. Chicago, IL: Hanley- Wood LLC. >6. Ozyildirim, C., and S. Lane. 2003. Evaluation of Self- Consolidating Concrete. Final report for the Virginia  Transportation Research Council, Charlottesville, VA, target="_blank" title="www.virginiadot.org/vtrc/main/online_reports/pdf/03-r13.pdf" href="http://www.virginiadot.org/vtrc/main/online_reports/pdf/03-r13.pdf">www.virginiadot.org/vtrc/main/online_reports/pdf/03-r13.pdf. >7. PCI. 2003. Guidelines for Self-Consolidating Concrete in Precast/Prestressed Concrete Institute Member Plants. TR-6-03. Chicago, IL: PCI. >8. Ramage, Brooke, Lawrence Kahn, and Kimberly Kurtis. 2004. Evaluation of Self-Consolidating Concrete for Bridge Structure Applications: Laboratory Investigation. Research report 04-2, p. 263,  School of Civil & Environmental Engineering, Georgia Institute of Technology, Atlanta, GA.  >9. target="_blank" title="ASTM C33-05" href="http://dx.doi.org/10.1520/c0033-07 ">ASTM C33-05. Standard Specification for Concrete Aggregates. In Annual Book of ASTM Standards, American Society for Testing and Materials. West Conshohocken, PA: ASTM International. >10. PCI Bridge Design Manual Steering Committee. 1999. Precast Prestressed Concrete Bridge Design Manual. MNL-133. Chicago, IL: PCI. >11. Horta, Alen. 2005. Evaluation of Self-Consolidating Concrete for Bridge Structure Applications. Mastera€?s thesis, p. 228, Georgia Institute of Technology, Atlanta, GA. >12. target="_blank" title="ASTM C42-05" href=" http://dx.doi.org/10.1520/c0042_c0042m-10 ">ASTM C42-05. Standard Test Method of Obtaining and Testing Drilled Cores and Sawed Beams of Concrete. In Annual Book of ASTM Standards, American Society for Testing and Materials. West  onshohocken,  PA: ASTM International.>13. Walker, Hollis N. 1992. Petr