Structural performance of fiber reinforced cementitious plinths in precast girder bridges

  • Received : 2020.11.27
  • Accepted : 2022.02.11
  • Published : 2022.05.10


Steel laminated elastomeric bearings are commonly used in bridge structures to control displacements and rotations and transfer forces from the superstructure to the substructure. Proper knowledge of design, fabrication and erection procedures is important to ensure stability and adequate structural performance during the lifetime of the bridge. Difference in elevations sometimes leads to large size gaps between the bearing and the girder which makes the grout thickness that is commonly used for leveling deviate beyond standards. This paper investigates the structural response of High Strength Fiber Reinforced Cementitious (HSFRC) thin plinths that are used to close gaps between bearing pads and precast girders. An experimental program was developed for this purpose where HSFRC plinths of different size were cast and tested under vertical loads that simulate bridge loading in service. The structural performance of the plinths was closely monitored during testing, mainly crack propagation, vertical reaction and displacement. Analytically, the HSFRC plinth was analyzed using the beam on elastic foundation theory as the supporting elastomeric bearing pads are highly compressible. Closed form solutions were derived for induced displacement and forces and comparisons were made between analytical and experimental results. Finally, recommendations were made to facilitate the practical use of HSFRC plinths in bridge construction based on its enhanced load carrying capacity in shear and flexure.



The authors are indebted to SODAMCO WEBER for providing the cementitious grout, for Spajic for providing the steel fibers and for Ocean Rubber Factory for providing the steel laminated elastomeric bearing pads. They also would like to acknowledge the contributions of Miroslav Tepacevic from Al-Meraikhi precast in this research.


  1. AASHTO (2017), American Association of State Highway and Transportation Officials, LRFD Bridge Design Specifications 8th Edition, Washington, USA.
  2. AASHTO (2017a), American Association of State Highway and Transportation Officials, LRFD Bridge Construction Specifications, 4th Edition, Washington, USA.
  3. Abohadima, S., Taha, M. and Abdeen, M.A.M. (2015), "General analysis of Timoshenko beams on elastic foundation", Math. Prob. Eng., 2015, Article ID 182523.
  4. Akhazhanov, S., Omarbekova, N., Mergenbekova, A., Zhunussova, G. and Abdykeshova, D. (2020), "Analytical solution of beams on elastic foundation", GEOMATE J., 19(73), 193-200.
  5. Al Osta, M.A. (2018), "Exploitation of ultrahigh-performance fibre-reinforced concrete for the strengthening of concrete structural members", Adv. Civil Eng., 2018, Article ID 8678124.
  6. British Standards Institution (2004), BS EN 10204:2004, British Standards, Metallic Products: Types of Inspection Documents United Kingdom.
  7. British Standards Institution (2005), BS EN 1337-3:2005, British Standards, Structural Bearings, Elastomeric Bearings, United Kingdom.
  8. Gergess, A. and Zahia-Douaihy, E. (2020), "Effects of elastomeric bearing stiffness on the structural behavior of bonded link-slabs", Transp. Res. Record, 2674(4), 428-443.
  9. Gergess, A.N., Shaikh Al Shabab, M. and Massouh, R. (2020), "Repair of severely damaged RC beams with high strength cementitious grout", Transp. Res. Record, 2674(6), 372-384.
  10. Girija-Vallabhan, C.V. and Das, Y.C. (1988), "Parametric study of beams on elastic foundations", J. Eng. Mech., 114(12), 2072-2083.
  11. Graybeal, B. (2018), Properties and Behavior of UHPC-Class Materials, No. FHWAHRT-18-036, Federal Highway Administration, Office of Infrastructure Research and Development, Washington, D.C.
  12. Hetenyi, M. (1946), Beams on Elastic Foundations: Theory with Applications in the Fields of Civil and Mechanical Engineering, University of Michigan Press, Ann Arbor, Michigan, USA.
  13. Luo, W., Yong, X. and Xiao-Qing, Z. (2018), "A general closed-form solution to a Timoshenko beam on elastic foundation under moving harmonics line load", Struct. Eng. Mech., 66(3), 387-397.
  14. Morteza, A. and Reza, A. (2013), "Inspection, condition evaluation and replacement of elastomeric bearings in road bridges", Struct. Infrastr. Eng., 9(9), 918-934.
  15. Safdar, M., Matsumoto, T. and Kakuma, K. (2016), "Flexural behavior of reinforced concrete beams repaired with ultra-high performance fiber reinforced concrete", Sci. Direct, 157, 448-460.
  16. Shokrieh, M. and Heidari-Rarani, M. (2011), "A comparative study for beams on elastic foundation models to analysis of mode-I delamination in DCB specimens", Struct. Eng. Mech., 3(2), 149-162.
  17. Young, W., Budynas, R. and Sadegh, A. (2012), Roark's Formulas for Stress and Strain, 8th Edition, The McGraw-Hill Companies, Inc., USA.