Ultimate Capacity of Undercut Fasteners Installed in Heat-Damaged Concrete
Publication: Journal of Structural Engineering
Volume 146, Issue 11
Abstract
The ultimate behavior and bearing capacity of undercut fasteners installed in heat-damaged concrete are investigated in this paper in which the results of a rather comprehensive research project are presented. Sixty-one fasteners (shank diameter ) are tested under a pull-out force after being installed in as many preheated and postdrilled slabs made of three different concretes: (1) a low-strength concrete (LSC), ; (2) a normal-strength concrete (NSC), ; and (3) a high-performance concrete (HPC), . Besides room temperature, five reference temperatures (between 200°C and 450°C at a prefixed distance from the heated surface) are considered to represent as many values of the fire duration prior to the instalment of the fastener. Four values of the embedment depth (45%, 60%, 80%, and 100% of the embedment suggested by the ) are investigated. In all cases, except in the virgin unheated specimens, the failure is caused by the thermally-damaged concrete, with the formation of a conical crack. Two finite-element (FE) models are formulated, based on linear-elastic fracture mechanics (LEFM) and on nonlinear fracture mechanics (NLFM), respectively, and their results are shown to envelop the test results. A third simple model based on linear fracture mechanics is also developed to quantify the extra loss of capacity induced by real fires in which the heating rate is one order of magnitude higher than in the electric furnaces generally used in the labs. Last but not least, to have information on the ultimate load associated with the possible formation of a conical crack, even in those cases in which the collapse due to shank yielding precedes concrete-cone failure (typically in high-grade virgin or undamaged specimens), the well-known concrete capacity method (CC-method) is modified to incorporate the maximum aggregate size, which plays a substantial role in crack mechanics.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
Italcementi Group—C.T.G. (Bergamo, Italy, now part of Heidelberg Cement Group) and CIS-E (Int. Center for the Constructions in Europe, Politecnico di Milano, Milan, Italy) are thanked for the financial support provided to this project on the Mechanical Behavior of Post-Installed Undercut Fasteners in Fir (2004–2014).
References
ACI (American Concrete Institute). 2001. Evaluating the performance of post-installed mechanical fasteners in concrete and commentary. ACI 355.2/ACI 355.2R. Farmington Hills, MI: ACI.
Bamonte, P., and P. G. Gambarova. 2005. “Residual behavior of undercut fasteners subjected to high temperatures.” In Vol. 2 of Proc., Int. fib Symposium “Keep Concrete Attractive,” edited by G. Balázs and A. Borosnyói, 1156–1163. Budapest, Hungary: Publishing Company of Budapest Univ. of Technology and Economics.
Bamonte, P., P. G. Gambarova, M. Bruni, and L. Rossini. 2007. “Ultimate capacity of undercut fasteners installed in thermally-damaged high-performance concrete.” In Vol. 3 of Proc., 6th Int. Conf. on Fracture Mechanics of Concrete and Concrete Structures “FraMCoS-6,” 1729–1736. London: Taylor & Francis.
Bamonte, P., P. G. Gambarova, A. Gorla, and A. Niglia. 2006. “Residual capacity of undercut fasteners installed in thermally-damaged concrete.” In Vol. 1 of Proc., 2nd Int. fib Congress, 234–235. Naples, Italy: fib Italia.
Cattaneo, S., and G. Guerrini. 2004. “Mechanical fasteners installed in high-performance fiber-reinforced concrete.” [In Italian.] In Proc. Nat. Conf. of the Italian Society for R/C and P/C Structures—AICAP, 101–112. Rome: Associazione Italiana Cemento Armato e Precompresso.
CEB. 1994. Fastenings to concrete and masonry structures. State-of-the-art report, bulletin d’information no. 216. London: Thomas Telford.
CEB. 1997. Design of fastenings in concrete. Design guide—Parts 1,2,3, bulletin d’information no. 233. London: Thomas Telford.
CEB-FIB. 1991. Model code 1990. London: Thomas Telford.
CEN (European Committee for Standardization). 2018. Eurocode 2: Design of concrete structures—Part 4: Design of fastenings for use in concrete. EN 1992-4. Brussels, Belgium: CEN.
Cheng, F. P., V. K. R. Kodur, and T. C. Wang. 2004. “Stress-strain curves for high strength concrete at elevated temperatures.” J. Mater. Civ. Eng. 16 (1): 84–90. https://doi.org/10.1061/(ASCE)0899-1561(2004)16:1(84).
Cook, R. A., D. M. Collins, R. E. Klingner, and D. Polyzois. 1992. “Load-deflection behavior of cast-in-place and retrofit concrete anchors.” ACI Struct. J. 89 (6): 639–649.
Elfgren, L., U. Ohlsson, and K. Gylltoft. 1989. “Anchor bolts analysed with fracture mechanics.” In Fracture of concrete and rock, edited by S. Shah and S. Swartz, 269–275. New York: Springer.
Eligehausen, R., J. Kožar, J. Ožbolt, and G. Periskic. 2005. “Transient thermal 3-D FE analysis of headed stud anchors exposed to fire.” In Proc., Int. Workshop “Fire Design of Concrete Structures: What now? What next?” edited by P. G. Gambarova, R. Felicetti, A. Meda, and P. Riva, 185–198. Brescia, Italy: Starrylink.
Eligehausen, R., and J. Ožbolt. 1998. Size effect in design of fastenings. Special volume on “Mechanics of quasi-brittle materials and structures,” edited by G. Pijaudier-Cabot, Z. Bittnar, and B. Gérard, 95–118. Paris: HERMES.
Felicetti, R., and P. G. Gambarova. 1998. “Effects of high temperature on the residual compressive strength of high-strength siliceous concretes.” ACI Mater. J. 95 (4): 395–406.
Fuchs, W., R. Eligehausen, and J. Breen. 1985. “Concrete capacity design (CCD) approach for fastening to concrete.” ACI Struct. J. 92 (1): 73–94.
Hlavička, J., and E. Lublóy. 2018. “Concrete cone failure of bonded anchors in thermally-damaged concrete.” Constr. Build. Mater. 171 (May): 588–597. https://doi.org/10.1016/j.conbuildmat.2018.03.148.
Hoehler, M. S., and R. Eligehausen. 2008. “Behavior and testing of anchors in simulated seismic cracks.” ACI Struct. J. 105 (3): 348–357.
ISO. 1999. Fire resistance tests—Elements of buildings construction, Part-1 General requirements. ISO 834-1. Geneva, Switzerland: International Organization for Standardization.
Muciaccia, G., A. Consiglio, and G. Rosati. 2016. “Behavior and design of post-installed rebar connections under temperature.” In Vol. 711 of Key engineering materials, 783–790. Baech, Switzerland: Trans Tech Publications.
Phan, L. T., and N. J. Carino. 2002. “Effects of test conditions and mixture proportions on behavior of high-strength concrete exposed to high temperatures.” ACI Mater. J. 99 (1): 54–66.
Pinoteau, N., J. V. Heck, P. H. Rivillon, P. Pimienta, T. Guillet, and S. Rémond. 2013. “Prediction of failure of a cantilever–wall connection using post-installed rebars under thermal loading.” Eng. Struct. 56 (Nov): 1607–1619. https://doi.org/10.1016/j.engstruct.2013.07.028.
Reick, M. 2001. “Fire behavior of fasteners embedded in a concrete mass and subjected to a pull-out force.” Ph.D. dissertation, News of the Dept. of Building Materials—IWB, Univ. of Stuttgart.
RILEM. 1985. Behavior of concrete at high temperatures: RILEM-Committee 44-PHT, edited by U. Schneider, 122. Kassel, Germany: Dept. of Civil Engineering, Gesamthochschule Kassel.
Sawade, G. 1994. “An energy-based material model to describe the load-bearing behaviour of concrete in tension.” [In German.] Ph.D. dissertation, Institut für Werkstoffe im Bauwesen, Univ. of Stuttgart.
Tian, K., J. Ožbolt, G. Periškić, and J. Hofmann. 2018a. “Concrete edge failure of single-headed stud anchors exposed to fire and loaded in shear: Experimental and numerical study.” Fire Saf. J. 100 (Sep): 32–44. https://doi.org/10.1016/j.firesaf.2018.07.001.
Tian, K., J. Ožbolt, A. Sharma, and J. Hofmann. 2018b. “Experimental study on concrete edge failure of single headed stud anchors after fire exposure.” Fire Saf. J. 96 (Mar): 176–188. https://doi.org/10.1016/j.firesaf.2018.01.005.
Zhang, B., and N. Bicanic. 2002. “Residual fracture toughness of normal- and high-strength gravel concrete after heating to 600°C.” ACI Mater. J. 99 (3): 217–226.
Information & Authors
Information
Published In
Copyright
©2020 American Society of Civil Engineers.
History
Received: Apr 15, 2019
Accepted: Feb 24, 2020
Published online: Aug 18, 2020
Published in print: Nov 1, 2020
Discussion open until: Jan 18, 2021
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.