This research presents an empirical study about the behavior of High Strength Concrete
beams under the static cyclic loading. It determines the influence of cyclic loading on the
moment capacity and deflection of HSC beams. A comparison of the mome
nt capacity and
deflection in both kinds of loading (monotonic and cyclic loading) were achieved.
High Strength Concrete mixture was designed, based on the specifications of the American
code ACI 211.4R-93. Thirty six concrete beams were prepared, nine of them were tested
under monotonic loading and the rest of beams were tested under cyclic loading. The
cyclic loading was performed for (5,10,15) cycles, at a range from zero to 65%, 75%, 85%
of the minimum expected monotonic load.
The results showed that the cyclic loading have positive effect on the flexural behavior of
HSC members, whereas the moment capacity increased and the deflection decreased,
especially at a range from zero to 75% of the minimum expected monotonic load, when
the number of cycles was 5,10,15.
This paper presents structural
analysis in using ANSYS programme for modeling of heat load then
comparison between the analytical results and experimental results is
performed .
The paper presents some of the results from a large experimental program undertakenat the Department of Civil Engineering of Damascus University. The project aims to study the ability to reinforce and strengthen the concrete by bars from Epoxy polymer reinforced with glass fibers (GFRP) and compared with reinforce concrete by steel bars in terms of mechanical properties.
Slabs are considered one of the most exposed elements to disasters and deformities
that can be clear to the viewer. These deformities are reflected as sign of defects that
appear clearly on big slabs. So, here comes the importance of applying and d
esigning
accurate slabs.
The purpose of this research is stating the need for persistent efforts to get a better
form of the slabs in order to increase their ability to be able to carry any outside extra
weights without the appearance of any deformities that might take place during the period
of investing the building. When deformities happen, they have bad effect on the beauty
and main function (purpose) of the building.
This research includes an experimental study for the real applicable slabs under our
supervision, in addition to a theoretical study about the deflection appearing on the slabs
by taking into consideration the plastic specifications of the concrete and the formation of
cracks.
This research aims at constructing reflexive deflections in the slabs during the
construction period and measuring the actual deformities and watching them through a
period of time, then comparing them with the theoretical expected deformities.
The findings that we could get at the end of our research are supposed to play a main
role in choosing the best design for the mandate slabs and at the same time getting the best
value for the reflexive deflection that can be used in the slab to make it better functionally
and to increase its ability to resist the outside applied weights. We hope this is just a start
for more research in this field.
The equipment of reinforced concrete by using native materials
(cement-aggregates-steel) in ideal conditions help us producing
concrete that consummate the Syrian Arab Code conditions, but
these are not found in Engineering Structure workshop that
have
affection of characters used materials in one hand, and these
behavior in the common work with steel –Structural behavior of
Engineering member espial in serviceability stage, that may be
expose accepted limits in other hand . So it is necessary to correct
the Syrian Arab Code's formulas of deformation and finding
suitable mathematical factors and formulas that insure structural
safety for reinforced concrete members under bending moment that casted in structure workshop circumstances in Syrian Arab
Republic.
The mixed use of steel bars and carbon rods in concrete beams can offer beams with different behaviour from that of steel reinforcement only. This paper studies the case of reinforcing concrete beams with two layers of bars, and the main parameters
investigated are the proportion and the distribution of carbon rods in the cross-section. Four groups containing 12 beams are tested, and each is reinforced with 4 bars located in two layers. The first group includes three control beams reinforced with steel bars, while the second includes three beams reinforced with carbon bars. Each of the third and fourth groups includes three beams reinforced with two steel bars and two carbon bars, whereas in the third group, steel bars are located above carbon ones, but in the fourth group, steel bars are located under carbon ones. Concrete beams reinforced with carbon rods in the second group exhibit a higher load carrying capacity and deflections, compared with other beams. However, the beams in the third and fourth groups have approximately the same load carrying capacity and the same behaviour up to the load level equal to 75% of their load carrying capacity. But after that, the beams in the fourth group become more deformed, compared with those of the third group.
Esthetic orthodontic archwires (fiber reinforced composite archwires) are
considered as the latest addition to orthodontic's world, and the load deflection rate is thought to be the
most important mechanical property of archwires which has strong e
ffect clinically, and this property is
affected by the cross section diameter and the material's type, for these reasons this study aims to
investigate the effect of the material's type and the cross section diameter of orthodontic archwires on the
load deflection rate of fiber reinforced composite(FRC) archwires with a diameter of 0.014 inch and
0.016 inch which are suitable for the leveling and alignment stage, and to compare these new materials
with Nickel titanium(NiTi) archwires .
