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http://dx.doi.org/10.12989/sem.2017.61.6.711

Effect of cover depth and rebar diameter on shrinkage behavior of ultra-high-performance fiber-reinforced concrete slabs  

Yoo, Doo-Yeol (Department of Architectural Engineering, Hanyang University)
Kwon, Ki-Yeon (Structural Systems & Site Evaluation Department, Korea Institute of Nuclear Safety)
Yang, Jun-Mo (Steel Structure Research Group, POSCO)
Yoon, Young-Soo (School of Civil, Environmental and Architectural Engineering, Korea University)
Publication Information
Structural Engineering and Mechanics / v.61, no.6, 2017 , pp. 711-719 More about this Journal
Abstract
This study investigates the effects of reinforcing bar diameter and cover depth on the shrinkage behavior of restrained ultra-high-performance fiber-reinforced concrete (UHPFRC) slabs. For this, twelve large-sized UHPFRC slabs with three different rebar diameters ($d_b=9.5$, 15.9, and 22.2 mm) and four different cover depths (h=5, 10, 20, and 30 mm) were fabricated. In addition, a large-sized UHPFRC slab without steel rebar was fabricated for evaluating degree of restraint. Test results revealed that the uses of steel rebar with a large diameter, leading to a larger reinforcement ratio, and a low cover depth are unfavorable regarding the restrained shrinkage performance of UHPFRC slabs, since a larger rebar diameter and a lower cover depth result in a higher degree of restraint. The shrinkage strain near the exposed surface was high because of water evaporation. However, below a depth of 18 mm, the shrinkage strain was seldom influenced by the cover depth; this was because of the very dense microstructure of UHPFRC. Finally, owing to their superior tensile strength, all UHPFRC slabs with steel rebars tested in this study showed no shrinkage cracks until 30 days.
Keywords
ultra-high-performance fiber-reinforced concrete; slab; shrinkage; degree of restraint; steel rebar; cover depth; rebar diameter;
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  • Reference
1 Aïtcin, P.C. (1999), "Demystifying autogenous shrinkage", Concrete Int. 21(11), 54-56.
2 American Society for Testing and Materials (ASTM) (2007), ASTM C 1437 Standard test method for flow of hydraulic cement mortar, Annual book of ASTM standards, ASTM, West Conshohocken, PA.
3 American Society for Testing and Materials (ASTM) (2008), ASTM C 403 Standard test method for time of setting of concrete mixture by penetration resistance, Annual book of ASTM standards, ASTM, West Conshohocken, PA.
4 American Society for Testing and Materials (ASTM) (2008), ASTM C 157/C 157M Standard test method for length change of hardened hydraulic-cement mortar and concrete, Annual book of ASTM standards, ASTM, West Conshohocken, PA.
5 Chang-Wen, M., Qian, T., Wei, S. and Jia-Ping, L. (2007), "Water consumption of the early-age paste and the determination of "time-zero" of self-desiccation shrinkage", Cement Concrete Res., 37(11), 1496-1501.   DOI
6 Chen, H.L.R. and Choi, J.H. (2011), "Analysis of shrinkage and thermal stresses in concrete slabs reinforced with GFRP rebars", J. Mater. Civil Eng., 23(5), 612-627.   DOI
7 Graybeal, B.A. (2008), "Flexural behavior of an ultrahighperformance concrete I-girder", J. Bridge Eng., 13(6), 602-610.   DOI
8 Habel, K., Charron, J.P., Denarie, E. and Bruhwiler, E. (2006), "Autogenous deformations and viscoelasticity of UHPFRC in structures. Part 1: Experimental results", Mag. Concr. Res., 58(3), 135-145.   DOI
9 Yoo, D.Y., Park, J.J., Kim, S.W. and Yoon, Y.S. (2013), "Early age setting, shrinkage and tensile characteristics of ultra high performance fiber reinforced concrete", Const. Build. Mater., 41, 427-438.   DOI
10 Yoo, D.Y., Banthia, N. and Yoon, Y.S. (2015), "Effectiveness of shrinkage-reducing admixture in reducing autogenous shrinkage stress of ultra-high-performance fiber-reinforced concrete", Cement Concrete Compos., 64, 27-36.   DOI
11 Yoo, D.Y., Park, J.J., Kim, S.W. and Yoon, Y.S. (2014b), Influence of reinforcing bar type on autogenous shrinkage stress and bond behavior of ultra high performance fiber reinforced concrete," Cement Concrete Compos., 48, 150-161.   DOI
12 Yoo, D.Y., Park, J.J., Kim, S.W. and Yoon, Y.S. (2014c), "Combined effect of expansive and shrinkage-reducing admixtures on the properties of ultra high performance fiberreinforced concrete", J. Compos. Mater., 48(16), 1981-1991.   DOI
13 Jiang, C., Yang, Y., Wang, Y., Zhou, Y. and Ma, C. (2014), "Autogenous shrinkage of high performance concrete containing mineral admixtures under different curing temperatures", Constr. Build. Mater., 61, 260-269.   DOI
14 Hossain, A.B. and Weiss, W.J. (2004), "Assessing residual stress development and stress relaxation in restrained concrete ring specimens", Cement Concrete Compos., 26(5), 531-540.   DOI
15 Japan Concrete Institute (JCI) (1999), Committee report, In: Tazawa E, editor, Autogenous shrinkage of concrete, E&FN Spon.
16 Japan Society of Civil Engineers (JSCE) (2004), Recommendations for design and construction of ultra-high strength fiber reinforced concrete structures (Draft), Japan Society of Civil Engineers, Tokyo, Japan.
17 Kamen, A., Denarie, E. and Bruhwiler, E. (2007), "Thermal effects on physico-mechanical properties of ultra-high-performance fiber-reinforced concrete", ACI Mater. J., 104(4), 415-423.
18 AFGC (2013), Ultra high performance fibre-reinforced concretes. Interim Recommendations, AFGC Publication, France.
19 Yoo, D.Y., Shin, H.O., Yang, J.M. and Yoon, Y.S. (2014a), "Material and bond properties of ultra high performance fiber reinforced concrete with micro steel fibers", Compos. Part B-Eng., 58, 122-133.   DOI
20 Yoo, D.Y., Yoon, Y.S. and Banthia, N. (2017), "Ultra-highperformance fiber-reinforced concrete: Shrinkage strain development at early ages and potential for cracking", J. Test. Eval., doi: http://dx.doi.org/10.1520/JTE20160114. (in Press)   DOI
21 Park, J.J., Yoo, D.Y., Kim, S.W. and Yoon, Y.S. (2014), "Benefits of using expansive and shrinkage reducing agents in ultra-highperformance concrete for volume stability", Mag. Concrete Res., 66(14), 745-750.   DOI
22 Kim, Y.J., Park, S.Y., Park, J.S. and Kim, B.S. (2013), "State-ofthe-art of UHPC applications in the World", Korean Soc. of Civil Eng., 61(2), 39-50. (in Korean)
23 Kobler, M. and Sobek, W. (2008), "The introduction of high forces into tine-walled UHPC elements by the use of implants", Proceedings of the Second International Symposium on Ultra High Performance Concrete, Kassel, Germany, 683-690.
24 Park, J.J., Yoo, D.Y., Kim, S.W. and Yoon, Y.S. (2013), "Drying shrinkage cracking characteristics of ultra-high-performance fibre reinforced concrete with expansive and shrinkage reducing agents", Mag. Concrete Res., 65(4), 248-256.   DOI
25 Perry, V. and Weiss, G. (2009), "Innovative field cast UHPC joints for precast bridge decks-Design, prototype testing and projects", Proceedings of the International Workshop on Ultra High Performance Fibre Reinforced Concrete, Designing and Building with UHPFRC: State of the Art Development, Marseille, France, AFGC/fib.
26 Sant, G., Lothenbach, B., Juilland, P., Le Saout, G., Weiss, J. and Scrivener, K. (2011), "The origin of early age expansions induced in cementitious materials containing shrinkage reducing admixtures", Cement Concrete Res., 41(3), 218-229.   DOI
27 Rajabipour, F., Sant, G. and Weiss, J. (2008), "Interactions between shrinkage reducing admixtures (SRA) and cement paste's pore solution", Cement Concrete Res., 38(5), 606-615.   DOI
28 Richard, P. and Cheyrezy, M. (1995), "Composition of reactive powder concretes", Cement Concrete Res., 25(7), 1501-1511.   DOI
29 Saleem, M.A., Mirmiran, A., Xia, J. and Mackie, K. (2011), "Ultra-high-performance concrete bridge deck reinforced with high-strength steel", ACI Struct. J., 108(5), 601-609.