In-Situ Evaluation of Two Concrete Slab Systems. I: Load Determination and Loading Procedure
This article is a reply.
VIEW THE ORIGINAL ARTICLEThis article has a reply.
VIEW THE REPLYPublication: Journal of Performance of Constructed Facilities
Volume 22, Issue 4
Abstract
The primary objective of in-situ load testing is to assess the safety and serviceability of an existing structural system with respect to a particular load effect. At this time, the most appropriate loading level and procedure, as well as the associated evaluation criteria are being reconsidered in light of technological advances in construction methods, analytical tools, and monitoring instrumentation. The in-situ load test method for reinforced concrete systems described in the ACI Building Code Requirements for Structural Concrete, namely the 24–h load test method and its evaluation criteria, has been in use for several decades, but may no longer serve the needs of contemporary construction and engineering practices. As a result, other load test methodologies and associated evaluation criteria are under development. This paper and a companion paper describe the rationale and application of an alternative approach to the determination of load level, loading procedure, instrumentation requirements, evaluation criteria and outcomes for two field projects. The first case study is relative to a posttensioned concrete slab where many areas were characterized by tendon and reinforcement misplacement, resulting in inadequate flexural strength and inadequate shear/flexure transfer at column/slab intersections. The second case study is the structural evaluation of a typical floor bay of a two-way reinforced concrete slab system, presenting distributed cracking at the positive and negative moment regions. Finite-element-method models were created for both structures to aid the load test design. The numerical models validated the field observations.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The ACI Concrete Research Council, the NSF Industry/University Cooperative Research Center on Repair of Buildings and Bridges with Composites and the UMR–University Transportation Center on Advanced Materials are gratefully acknowledged for their financial support to the research. Yizhuo Chen assisted with the load tests and data reduction and his assistance is greatly appreciated.
References
American Concrete Institute (ACI). (1920). “Standard building regulations for the use of reinforced concrete,” Standard Specification No. 23, Detroit.
American Concrete Institute (ACI). (1936). “Building code regulations for reinforced concrete.” ACI 501-36T, Detroit.
American Concrete Institute (ACI). (2004). “Strength evaluation of existing concrete buildings.” ACI 437R-03, ACI Committee 437, Farmington Hills, Mich.
American Concrete Institute (ACI). (2005). “Building code requirements for structural concrete.” ACI 318–05, Farmington Hills, Mich.
American Concrete Institute (ACI). (2007). “Test load magnitude, protocol and acceptance criteria.” ACI 437.1R-07, ACI Committee 437, Farmington Hills, Mich.
ASME. (2004a). “Section V—Nondestructive examination.” Boiler and pressure vessel code, New York.
ASME. (2004b). “Section X—Fiber-reinforced plastic pressure vessels.” Boiler and Pressure Vessel Code, New York.
ASTM. (2006). “Standard terminology for nondestructive examinations.” ASTM E 1316 06a, West Conshohocken, Pa.
Birkmire, W. (1894). Skeleton construction in buildings, Wiley, New York.
Bungey, J. (1989). The testing of concrete in structures, 2nd Ed., Chapman and Hall, New York.
Casadei, P., Parretti, R. Nanni, A. and Heinze, T. (2005), “In-situ load testing of parking garage RC slabs: Comparison between and cyclic load testing.” Pract. Period. Struct. Des. Constr., 10(1), 40–48.
Computers and Structures, Inc. (2000). SAP 2000, Version II, Berkeley, Calif.
FitzSimons, N., and Longinow, A. (1975). “Guidance for load tests of buildings.” J. Struct. Div., 101(7), 1367–1380.
Galati, N., Casadei, P., Lopez, A., and Nanni, A. (2004). “Load test evaluation of Augspurger ramp parking garage, Buffalo, N.Y.” Rep. No. 04-50, Center for Infrastructure Engineering Studies, Univ. of Missouri-Rolla, Rolla, Mo.
Galati, N., and Nanni, A. (2006). “Load testing of two post-tensioned concrete slabs at garage A. Windsor on the Plaza, Kansas City, Mo.” Final Rep., Prepared for Simpson Gumpertz & Heger Inc., Univ. of Missouri-Rolla, Rolla, Mo.
Galati, N., and Nanni, A. (2007). “In-situ structural evaluation of a two-way RC slab at the National Institute of Health, Bethesda, Maryland.” Final Rep., Prepared for Simpson Gumpertz & Heger Inc., Univ. of Missouri-Rolla, Rolla, Mo.
Gold, W. J., and Nanni, A. (1998). “In-situ load testing to evaluate new repair techniques.” Proc., NIST Workshop on Standards Development for the Use of FRP for the Rehabilitation of Concrete and Masonry Structures, Tucson, Ariz., NISTR 6288, D. Duthinh, ed., Feb. 1999, 3-102/112.
Mettemeyer, M., and Nanni, A. (1999). “Guidelines for rapid load testing of concrete structural members.” Rep. No. 99-5, Center for Infrastructure Engineering Studies, Univ. of Missouri-Rolla, Rolla, Mo.
Nanni, A., and Gold, W. (1998a). “Evaluating CFRP strengthening systems in-situ.” Concrete Repair Bull., Int. Concrete Repair Ins., 11(1), 12–14.
Nanni, A., and Gold, W. J. (1998b). “Strength assessment of external FRP reinforcement.” Concr. Int., 20(6), 39–42.
NDIS 2421. (2000). “Recommended practice for in situ monitoring of concrete structures by acoustic emission.” Japanese Society for Non-Destructive Inspection.
RILEM Technical Committee 20-TBS. (1984). “General recommendation for statical loading test of load-bearing concrete structures in situ (TBS2).” RILEM technical recommendations for the testing and use of construction materials, E & FN Spon, London, 379–385.
Ziehl, P. H., Galati, N., Nanni, A., and Tumialan, J. G. (2008). “In situ evaluation of two concrete slab systems. II: Evaluation criteria and outcomes.” J. Perform. Constr. Facil., 22(4), 217–227.
Information & Authors
Information
Published In
Journal of Performance of Constructed Facilities
Volume 22 • Issue 4 • August 2008
Pages: 207 - 216
Copyright
© 2008 American Society of Civil Engineers.
History
Received: Sep 10, 2007
Accepted: Jan 15, 2008
Published online: Aug 1, 2008
Published in print: Aug 2008
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.