Nonlinear Strut-Tie Model Analysis of Pre-Tensioned Concrete Deep Beams

Abstract

To date, many studies have been conducted for the analysis and design of disturbed regions. However, prestressed concrete deep beams have not been the subject of much dedicated effort. This paper presents an evaluation of the behavior and strength of two pre-tensioned concrete deep beams tested to shear failure using a nonlinear strut-tie model approach. In this approach, the effective prestressing forces represented by equivalent external loads are gradually introduced along tendon's transfer length in the nearest strut-tie model joints, the friction at the interface of main diagonal shear cracks is modeled by diagonal struts along the direction of the cracks in strut-tie model, and additional positioning of concrete ties at the place of steel ties is incorporated. Through strut-tie model analysis of pre-tensioned concrete deep beams, the nonlinear strut-tie model approach proved to present effective solutions for predicting the essential aspects of the behavior and strength of pre-tensioned concrete deep beams.

Keywords

pre-tensioned concrete deep beam strut-tie model transfer length aggregate interlock

References

Alshegeir

(1992). Analysis and Design of Disturbed Regions with Strut-Tie Models, Ph. D. Thesis, School of Civil Engineering, Purdue University, West Lafayette, Indiana, USA, 274 pp.

Alshegeir

and Ramirez

J.A.

(1992). “Strut-Tie approach in pretensioned deep beams”, ACI Structural Journal, Vol. 89, No. 3, pp. 296–304.

Burdet

(1990). Analysis and Design of Anchorage Zones in Post-Tensioned Concrete Bridge, Ph. D. Thesis, The University of Texas, Austin, Texas, USA, 432 pp.

Hanson

N.W.

and Kaar

P.H.

(1959). “Flexural bond tests of pretensioned prestressed beams”, ACI Journal, Vol. 30, No. 7, pp. 783–802.

Kaufman

M.K.

and Ramirez

J.A.

(1989). Structural Behavior of High Strength Concrete Prestressed I-Beams, Report No. FHWA, IN JHRP-88/6, Joint Highway Research Project, Purdue University, West Lafayette, Indiana, USA, 228 pp.

Schlaich

Schaefer

and Jennewein

(1987). “Towards a consistent design of structural concrete”, Journal of the Prestressed Concrete Institute, Vol. 32, pp. 74–150.

Siao

W.B.

(1993). “Strut-and-tie model for shear behavior in deep beams and pile caps failing in diagonal splitting”, ACI Structural Journal, Vol. 90, No. 4, pp. 356–363.

Siao

W.B.

(1994). “Shear strength of short reinforced concrete walls, corbels, and deep beams”, ACI Structural Journal, Vol. 91, No. 2, pp. 123–133.

Yun

Y.M.

and Ramirez

J.A.

(1996). “Strength of struts and nodes in strut-tie model”, Journal of Structural Engineering, ASCE, Vol. 122, No. 1, pp. 20–29.

10.

Yun

Y.M.

(2000). “Computer graphics for nonlinear strut-tie model approach”, Journal of Computing in Civil Engineering, ASCE, Vol. 14, No. 2, pp. 127–133.

11.

Yun

Y.M.

(2000). Design and Analysis of 2-D Structural Concrete with Strut-Tie Model, Ph. D. Thesis, School of Civil Engineering, Purdue University, West Lafayette, Indiana, USA, 247 pp.

12.

Yun

Y.M.

(2000). “Nonlinear strut-tie model approach for structural concrete”, ACI Structural Journal, Vol. 97, No. 4, pp. 581–590.

13.

Yun

Y.M.

(2004). “Evaluation of ultimate strength of post-tensioned anchorage zones”, International Journal of Advances in Concrete Technology, Accepted for Publication.