Browse > Article
http://dx.doi.org/10.4334/JKCI.2014.26.5.615

Measurement and Prediction of Long-term Deflection of Flat Plate Affected by Construction Load  

Hwang, Hyeon-Jong (Dept. of Architecture, Seoul National University)
Park, Hong-Gun (Dept. of Architecture, Seoul National University)
Hong, Geon-Ho (Dept. of Architectural Engineering, Hoseo University)
Kim, Jae-Yo (Dept. of Architectural Engineering, Kwangwoon University)
Kim, Yong-Nam (Housing Eng. Team, Samsung Engineering and Construction)
Publication Information
Journal of the Korea Concrete Institute / v.26, no.5, 2014 , pp. 615-625 More about this Journal
Abstract
Excessive long-term slab deflection caused by construction load is a critical issue for the design of concrete slabs, as long span flat plates become popular for tall buildings. In the present study, the effect of construction load causing early slab cracking on the long-term deflection was theoretically studied. On the basis of the result, a numerical analysis method was developed to predict the long-term deflection of flat plates. In the proposed method, immediate deflection due to slab cracking and long-term effect of creep and shrinkage were considered. To verify the construction load effect, long-term slab deflections were measured in actual flat plate buildings under construction. The results showed that the immediate deflection due to the construction load increased significantly the long-term deflection. The proposed method was used to predict the deflections of the buildings. The results were compared with the measurement results. The predictions agree well with the long-term deflections of flat plate affected by construction load.
Keywords
flat plate; construction load; cracking; long-term deflection;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
연도 인용수 순위
1 Mosallam K. H., and Chen W. F., "Determining Shoring Loads for Reinforced Concrete Construction," ACI Structural Journal, Vol. 88, No. 3, 1991, pp. 340-350.
2 Gardner, N. J., and Fu, H. C., "Effects of High Construction Loads on the Long-Term Deflections of Flat Slabs," ACI Structural Journal, Vol. 84, No. 3, 1987, pp. 349-360.
3 Kang, S. H., Choi, K. K., and Park, H. G., "Minimum Thickness Requirements of Flat Plate Affected by Construction Load," Journal of the Korean Concrete Institute, Vol. 15, No. 5, 2003, pp. 650-661.   과학기술학회마을   DOI   ScienceOn
4 Kim, J. Y., "Applications of Practical Analysis Scheme for Evaluating Effects of Over-Loads during Construction on Deflections of Flat Plate System," Journal of the CSEIK, Vol. 22, No. 1, 2009, pp. 25-34.   과학기술학회마을
5 ACI Committee 347, "Guide for Shoring/Reshoring of Concrete Multistory Buildings (ACI 347.2R-05)," American Concrete Institute, Farmington Hills, MI, 2005, pp. 18.
6 Grundy, P., and Kabaila, A., "Construction Loads on Slab with Shored Formwork in Multistory Buildings," ACI Journal, Vol. 60, No. 12, 1963, pp. 1729-1738.
7 Liu, X., Chen, W. F., and Bowman, M. D., "Construction Load Analysis for Concrete Structures," Journal of Structural Engineering, ASCE, Vol. 111, No. 5, pp. 1019-1036.
8 El-Shahhat, A. M., and Chen, W. F., "Improved Analysis of Shore-Slab Interaction," ACI Structural Journal, Vol. 89, No. 5, 1992, pp. 528-537.
9 Park, H.G., Hwang, H.J., Hong, G.H., Kim, Y.N., and Kim, J.Y., "Slab Construction Load Affected by Shore Stiffness and Concrete Cracking," ACI Structural Journal, Vol. 108, No. 6, 2011, pp. 679-688.
10 Lee, J.I. and Scanlon, M.A., "Effect of Early Age Loading on Time-Dependent Deflection and Shrinkage Restraint Cracking of Slabs with Low Reinforcement Ratios," ACI Special Publication, SP-246, 2007, pp. 149-166.
11 ACI Committee 318, "Building Code Requirements for Structural Concrete and Commentary (ACI 318-11)," American Concrete Institute, Farmington Hills, MI, 2011, pp. 473.
12 Vollum, R.L., Moss, R.M., and Hossain, T.R., "Slab Deflections in the Cardington in-situ Concrete Frame Building," Magazine of Concrete Research, Vol. 54, No. 1, 2002, pp. 23-34.   DOI   ScienceOn
13 Hossain, T.R. and Vollum, R.L., "Prediction of Slab Deflections and Validation Against Cardington Data," Proceedings of the Institution of Civil Engineers, Structures and Buildings, Vol. 152, No. 3, 2002, pp. 235-248.   DOI   ScienceOn
14 CEB-FIP, "CEB-FIP Model Code 1990, Design Code," Comite Euro-International, Thomas Telford, London, UK, 1993, pp. 437.
15 Hossain, T.R., Vollum, R., and Ahmed, S.U., "Deflection Estimation of Reinforced Concrete Flat Plates Using ACI Method," ACI Structural Journal, Vol. 108, No. 4, 2011, pp. 405-413.
16 Mehta, P.K. and Monteiro, P.J.M., "Concrete: Microstructure, Properties, and Materials, third edition," McGraw-Hill, New York, 2006, pp. 63-65.
17 BS EN, "Eurocode 2: Design of Concrete Structures," British Strandards, UK, 2004, pp. 225.
18 Bischoff, P.H. and Scanlon, A., "Effective Moment of Inertia for Calculating Deflections of Concrete Members Containing Steel Reinforcement and Fiber-Reinforced Polymer Reinforcement," ACI Structural Journal, Vol. 104, No. 8, 2007, pp. 68-75.
19 Carino, N.J. and Lew, H.S., "Temperature Effects on Strength- Maturity Relations of Mortar," ACI Journal, Proceedings, Vol. 80, No. 3, 1983, pp. 177-182.
20 Park, H.G., Hwang, H.J., Hong, G.H., Kim, Y.N., and Kim, J.Y., "Immediate and Long-Term Deflections of Reinforced Concrete Slabs Affected by Early-Age Loading and Low Temperature," ACI Structural Journal, Vol. 109, No. 3, 2012, pp. 413-422.
21 Fikry, A.M. and Thomas, C., "Development of a Model for the Effective Moment of Inertia of One-Way Reinforcement Concrete Elements," ACI Structural Journal, Vol. 95, No. 4, 1998, pp. 444-455.
22 Neville, A.M., "Recovery of Creep and Observations on the Mechanism of Creep of Concrete," Applied Scientific Research, Vol. 9, No. 1, 1960, pp. 71-84.   DOI
23 ACI Committee 209, "Prediction of Creep, Shrinkage, and Temperature Effects in Concrete Structures (ACI 209R-92)," American Concrete Institute, Farmington Hills, MI, 1992, pp. 47.