Normal and High-Strength R/C Deep Beams under Pure Torsion and Codes Evaluation.

Document Type : Research Studies

Author

Structural Engineering Department., Faculty of Engineering., El-Mansoura University., Mansoura., Egypt

Abstract

Fourteen reinforced concrete deep beams were tested under pure torsion in order to evaluate the torsion design provisions of ACI 318-02 Building Code, the Egyptian code (ECCS-2001), the New Zealand code (NZS 3101-95), and the Eurocode 2 (EC-2) when applied to High Strength Concrete (HSC) deep beams. The results of these tests have been used to compare the torsional behavior of reinforced deep beams constructed from Normal-Strength Concrete (NSC with characteristic cube compressive strength fcu of about 35 MPa) and HSC (with fcu of about 81 MPa). The main parameters examined in this study were the design compressive strength, the provided transverse reinforcement ratio, the quantity of longitudinal and skin reinforcement and the size of the tested beams in the form of the tested span to total height ratio (L/h=1.0, 2.0 and 3.0). The results showed that the reserve in the torsional strength of the HSC deep beams aster cracking is considerably less than that of the similar NSC deep beams. The cracking torsional strength of the tested NSC deep beans is about 38-54% of the measured ultimate torsional strength, while the same ratio for the similar HSC deep beams is about 57-77% of the measured ultimate strength. The design torsional strength equations of the four international codes considered in this study were safe and conservative when applied to NSC and HSC deep beams. The predictions of the ultimate torsional strength of the deep beams according to the method of ACI 318-02 and using a value of the angle between the concrete struts and the longitudinal axis of the beam θ equal to 45 deg may give a conservative results less than that calculated using this angle between 30 and 60 deg. 

Main Subjects

Files

Share

How to cite

Statistics