الفهرس 
AbstractOnly 14 pages are availabe for public view
 |  | from | 171 |  |  |
| | | from | 171 | | |
Abstract
Torsion can be a significant action in many structural members that are part of
civil engineering infrastructure. Curved bridges, spiral stair cases, eccentrically loaded
box girder bridges, cantilevered slabs and spandrel beams under gravity loads exhibit
torsional forces. Most of the recent researches study the behavior of fiber reinforced
polymer (FRP) strengthened reinforced concrete beams subjected to torsional loads
.Many analytical and experimental methods were introduced for evaluation of the
torsional capacity of FRP, but developing the common method of reinforcement
(longitudinal or transverse) to improve the torsional resistance of RC structural
elements had paid less attention, hence comes the importance of this thesis which offer
a new technique of reinforcing RC beams so that to over come the cease of additional
loads resistance.
This technique based on nsmg the capacity of RC elements subjected to
torsional loading which develops shear stresses by using transverse in different
configuration, the shape of the stirrups was ellipsoidal and spiral. The effect of other
parameters such as variation in longitudinal steel amount and fiber addition was also
investigated.
The main objective of this study is to give better understanding of the torsional
behavior of rectangular reinforced concrete beams reinforced with different transverse
steel configurations.
The experimental program involves testing twenty one reinforced concrete beams
with Rectangular cross section to study their torsional behavior. Three beams were kept
as control beams. The rest of the twenty one beams were divided into six groups.
Groups (G 1, G2 and G3), contains three beams each, of ellipsoidal, spiral stirrups
configuration and different longitudinal reinforcement amount respectively. Groups
(G4, G5 and G6) identical to the previous groups in -addition to this certain volume
percentage of polypropylene fiber were added to concrete mixture.
The most important variables studied in this research were different transverse
scheme, longitudinal reinforcement amount and the addition of polypropylene fiber to
the mixture. The beams dimension and surface preparation were nearly identical. All
beams were tested under identical loading condition. During the tests, cracking loads,
ultimate torsional loads and angle of twist were measured.