Title: Shear Strength of Sand-Lightweight Concrete Deep Beams with Steel Fibers

Author(s): Sergio Garcia, Allonso Pereira, and Rodrigo Pierott

Publication: Structural Journal

Volume: 118

Issue: 2

Appears on pages(s): 203-214

Keywords: deep beams; sand-lightweight; shear; steel fibers

DOI: 10.14359/51729347

Date: 3/1/2021

Abstract:
Six deep beams without transversal reinforcement made of sand-lightweight concrete and six deep beams made of sand-lightweight concrete with 1.0% of steel fibers were tested and compared with conventional concrete deep beams with and without fibers. The shear-span to deep beam height ratio (a/h) was 0.5, 0.8, and 1.0. The cross section heights were 400, 600, and 700 mm (15.7, 23.6, and 27.6 in.). The deep beams were tested to failure under a four-point bending test, using a hydraulic actuator with 500 kN (674 kip) capacity load cell. After testing, it was concluded that the shear-strength values were smaller in larger span deep beams. The presence of steel fibers increased the maximum strength and contributed quantify to the strength to diagonal cracking. The maximum shear load in steel fiber deep beams increased by approximately 16%. The size effect was more significant in sand-lightweight concrete deep beams. Besides, it was proposed a coefficient to validate the cracking strut-and-tie model (CSTM) to evaluate the applicability in deep beams of sand-lightweight concrete with and without steel fibers and the experimental maximum shear predictions are compared according to some codes for sand-lightweight concrete deep beams and by codes and some codes and researchers for sand lightweight concrete deep beams with steel fibers.