Shear Strength and Behavior of High Strength Reinforced Concrete Beams without Stirrups

Jalal Ahmad Saeed, Abbas Mohammed Abubaker [Department of Civil Engineering - University of Sulaimani]

Received : 15/03/2015, Accepted : 20/12/2015

DOI Link:


This paper presents test results of twelve high strength reinforced concrete (HSRC) beams without stirrups which were tested to investigate their shear strength and behavior under loading. The shear behavior, ultimate load-carrying capacity, and mode of failure are presented. The applicability the ACI 318M-11, Modified Zsutty, and Sudheer et al, the influences of shear span to effective depth ratio (a/d) and compressive strength (fc') on their shear strength are also presented. It is found that, In general, with increasing each of compressive strength and (a/d) ratio the failure loads and consequently the shear strength of the beams didn't increase significantly. It is also found that ACI 318 M-11 overestimates for some test results (unsafe) while Sudheer et al equation underestimates for all test results excessively. However, Modified Zsutty equation underestimates the tested values for all the tested beams and could estimate shear capacity satisfactorily within a reasonable factor of safety. A regression equation was proposed and it was found to be more reliable and safe in predicting shear strength of high strength reinforced concrete beams.

KEYWORDS: shear strength, high strength. Stirrups


1. ACI committee 363.2R -98," Guide to Quality Control and Testing of High-Strength Concrete", Reported by ACI Committee 363, American Concrete institute, 1998.

2. Attaullah Shah, "Evaluation of Shear Strength of High Strength Concrete Beams", PhD thesis , University of Engineering & Technology Taxila Pakistan ,June 2009,p(19-20, 25, 37-42, 246-248).

3. ASTM Designation C150 -04, "Standard Specification for Portland Cement", Annual Book of ASTM Standard, Vol. 04 ,May 2004.

4. ASTM Designation C1240 -03, " Standard Specification for Use of Silica Fume as a Mineral Admixture in Hydraulic- Cement Concrete, Mortar, and Grout", Annual Book of ASTM Standard, Vol. 04, October 2005.

5. ASTM Designation C33 -03, " Standard Specification for Concrete Aggregates", Annual Book of ASTM Standard, Vol. 04, October 2005.

6. ACI 318M-11," Building Code Requirements for Structural Concrete (ACI 318M-11), An ACI Standard and Commentary", American Concrete institute,2011.

7. BS1881-116,"Method For Determination Of Compressive Strength Of Concrete Cubes", British Standard, 1983.

8. ASTM Designation C496/C496M-04," Standard Test Method for Splitting Tensile Strength of Cylindrical Concrete Specimens", Annual Book of ASTM Standard, Vol. 04, October 2005.

9. Faisal F. Wafa, Samir A. Ashour and Ghazi S. Hasanain, " Shear Behavior Of Reinforced High Strength Concrete Beams Without Shear Reinforcement", Engineering Journal of Qatar University, Vol. 7, 1994, p(91 - 113).

10. Sudheer Reddy.L, Ramana Rao .N.V, Gunneswara Rao T.D, "Shear Resistance of High Strength Concrete Beams Without Shear Reinforcement", International Journal of Civil and Structural Engineering, Volume 1, No 1, 2010,p(101-113).

11. Imran A Bukhari and Saeed Ahmad, " Evaluation of Shear Strength of High-Strength Concrete Beams without Stirrups", The Arabian Journal for Science and Engineering, Volume 33, No.2B, Oct. 2008, pp (321– 335).