Engineering and Technology Journal

This study deals with, experimentally, the effect of flange dimensions on shear
behavior of normal strength concrete (NSC) and self-compacting concrete (SCC)
double Tee beams.
Twelve beam specimens as well as a series of control specimens are tested. The
beam specimens were divided into two groups (based on concrete type) and each
group are divided into five subgroups (based on flange dimensions).The webs
dimensions, beam depth, beam length, spacing between webs, longitudinal
(tension) reinforcement and transverse reinforcement (stirrups) were kept constant
in all beam specimens.
Experimental results showed that the ultimate capacity increased about (6%-
12) and (9%-20) when the flange width (dimensions) increased from (320mm) to
(450mm) for NSC and SCC respectively. Presence of large compression flange
lead to increase the stiffness of tested beams due to contribution of additional
concrete parts, and this leads to increase in carrying capacity.

Reactive powder concrete (RPC) is a new type of ultra-high strength and high ductility concrete first developed in the 1990's in France. It is recognized as a revolutionary material that provides a combination of ductility, durability, and high strength. In this research work the nonlinear f ini t e element investigation on the behavior of RPC
beams is presented. This investigation is carried out in order to get a better understanding of their behavior throughout the entire loading history. Also, a numerical parametric study was carried out on the RPC beams to investigate the influence of fibrous concrete compressive strength ( ) cf f ¢ , tensile reinforcement ratio ( ) w r , fiber content ( Vf ) and shear span to effective depth ratio (a/d) on the shear behavior and ultimate load capacity of these beams.
The three- dimensional 20-node brick elements are used to model the concrete, while the reinforcing bars are modeled as axial members embedded within the concrete brick elements. The compressive behavior of concrete is simulated by an elastic-plastic work-hardening model followed by a perfectly plastic response, which terminated at the onset of crushing. In tension, a fixed smeared crack model has been
used.

This paper presents results of an experimental investigation involving eight
tests on 1800mm long reinforced concrete (RC) beams strengthened in shear with
externally bolted carbon fiber reinforced polymer (CFRP) composites. The overall
objective of this study was to investigate the shear performance and failure modes
of RC beams strengthened with externally fixed carbon FRP (CFRP) manufactured
U-warp strips and the specific goal was to keep the CFRP strips working till the
beam reaches its flexural failure because in most of the previous researches the
CFRPs debonded from the concrete surface and the failure (separation) happened
in the concrete. The variables investigated within this program included: CFRP
spacing and number of CFRP layers. The experimental results indicated that the
contribution of externally fixed CFRP strips to the shear capacity is significant and
depends on the variables investigated. In all the beam specimens (with end
anchorage) the debonding was not observed.

This research work presents a nonlinear finite element investigation on the
behavior of reinforced concrete beams with a small amount of web reinforcement under
shear. This investigation is carried out in order to get a better understanding of their
behavior throughout the entire loading history.
The three- dimensional 20-node brick elements are used to model the concrete, while
the reinforcing bars are modeled as axial members embedded within the concrete brick
elements. The compressive behavior of concrete is simulated by an elastic-plastic
work-hardening model followed by a perfectly plastic response, which terminated at
the onset of crushing. In tension, a fixed smeared crack model has been used.