Influence of Loading Rate on Shear Failure Resistance of RC Beams

Abstract:

The aim of this study was to investigate the dynamic shear failure behavior of RC beams under rapid loading through an experimental study. Thus, rapid loading test for 48 RC beams was performed, in which shear span-to-depth ratio, shear reinforcement ratio and loading rate were variable. The RC beams exhibited diagonal tension failure, shear compression failure and flexural failure depending mainly on the shear span-to-depth ratio and the shear reinforcement ratio. The influence of loading rate on the maximum resistance is more significant for the RC beams failed in shear than for those failed in flexure.

• Periodical: Applied Mechanics and Materials (Volume 82)
• Pages: 229-234
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.82.229
• Online since: July 2011
• Authors: Takashi Fukuda, Shotaro Sanuki, Masaki Miyakawa, Kazunori Fujikake
• Keywords: Dynamic Shear Failure, Dynamic Shear Resistance, Loading Rate, RC Beam

References

[1] Hughes, G., and Beeby, A. W.: Investigation of the effect of impact loading on concrete beams, The Structural Engineer, 60B (3), pp.45-52, 1982.

[2] Bresler, B. and MacGregor, J. G.: Review of Concrete Beams Failing in Shear, Journal of Structural Division, ASCE, Vol.93, No. ST1, pp.343-372, 1967.

DOI: 10.1061/jsdeag.0001586

[3] Japan Society of Civil Engineers (JSCE) (2002). " Standard Specifications for Concrete Structures 2002", Structual Performance Verification (in Japanese) Table 1 Test case detail Designation Shear span ratio Shear reinforcement ratio pw[%] Loading rate [m/s] Designation Shear span ratio Shear reinforcement ratio pw[%] Loading rate [m/s] RC1S0S 1.90 0 4.0×10-4 RC3S0S 3.33 0 4.0×10-4 RC1S0L 4.0×10-2 RC3S0L 4.0×10-2 RC1S0M 4.0×10-1 RC3S0M 4.0×10-1 RC1S0H 2.0×100 RC3S0H 2.0×100 RC1S42S 0.42 4.0×10-4 RC3S42S 0.12 4.0×10-4 RC1S42L 4.0×10-2 RC3S42L 4.0×10-2 RC1S42M 4.0×10-1 RC3S42M 4.0×10-1 RC1S42H 2.0×100 RC3S42H 2.0×100 RC1S84S 0.84 4.0×10-4 RC3S84S 0.60 4.0×10-4 RC1S84L 4.0×10-2 RC3S84L 4.0×10-2 RC1S84M 4.0×10-1 RC3S84M 4.0×10-1 RC1S84H 2.0×100 RC3S84H 2.0×100 RC1 S Shear span - to - depth ratio RC 1 = 1 . 90 % RC 3 = 3 . 33 % Shear reinforcement ratio S 0 = 0 % S 12 = 0 . 12 % S 42 = 0 . 42 % S 60 = 0 . 60 % S 84 = 0 . 84 % Loading rate S = 4 . 0 × 10 - 4 m / s L = 4 . 0 × 10 - 2 m / s M = 4 . 0 × 10 - 1 m / s H = 2 . 0 × 10 0 m / s S42 Fig.1 Test case designation (a) RC1 (b) RC3 Fig.2 RC beam specimen detail Table 2 Flexure and shear resistances of RC beams Specimen Flexure reinforcement ratio[%] Shear reinforcement ratio[%] Design flexural resistance[kN] Design shear resistance[kN] Safety margin of shear strength Expected failure mode RC3S0 2.46 0 121.8 66.8 0.55 Shear RC3S12 0.12 86.5 0.71 Shear RC3S60 0.60 165.1 1.36 Flexure RC1S0 0 213.1 121.0 0.57 Shear RC1S42 0.42 189.8 0.89 Shear RC1S84 0.84 230.0 1.08 Flexure Fig.3 Servo-controlled rapid loading machine Fig.4 Arrangement of strain gages for reinforcing bars Fig.5 Arrangement of concrete strain gages and accelerometers Fig.6 Typical failure modes of RC beams (c) RC1S84 (b) RC1S42 (a) RC1S0 (f) RC3S60 (e) RC3S12 (d) RC3S0 Fig.7 Load–midspan deflection relationships of RC specimens (b) RC3 (a) RC1 Fig.8 Relationship between loading rate and dynamic increase ratio of max. resistance