| الملخص | The State of Qatar is continuously suffering from the high temperature and humidity
which take place most of the year. This can deteriorate and reduce the lifecycle of the
reinforced concrete (RC) structures and may increase the possibilities of the corrosion.
Recently, composite materials science was developed and produced new non-corrosive
composite material like fiber reinforced polymers (FRP). The natural properties of the
FRP bars such as low density with high strength, lightweight material, lower lifecycle
cost, and corrosion resistance made it preferable reinforcement material in the
construction.
Ever since FRP has been used in different concrete elements. However, in continuous
beams, the moment redistribution between hogging and sagging sections are still under
investigation due to the brittle property of the FRP bars.
The aim of this study is to investigate numerically the impact of using basalt macro
fibers (BMF) combined with basalt fiber reinforced polymer (BFRP) bars on the
moment redistribution of continuous concrete beams.
The study is focusing mainly on using the finite element analysis (FEA) to investigate
the moment redistribution in continuous beams reinforced with BFRP bars. Different
FE models were simulated using ABAQUS 6-14 software. They were successfully
calibrated using experimental data for flexural testing of continuous RC beams
conducted in the Qatar University structural lab. The FE models were verified through the stress-strain diagrams in which they were matching within the accepted range. The
simulated beams were two spans with a size of 200 x 300 x 2000 mm each.
An extensive parametric study was conducted using 144 simulated beams to figure out
the key parameters that affect the moment redistribution. The parameters taken into
consideration were the BMF volume fraction (0%, 0.75% and 1.5%), stirrups spacing
(80 mm, 100 mm and 120 mm), and BFRP bars reinforcement ratio (0.6, 1.0, 1.8
and 2.8).
In addition, statistical regression analysis was performed using Minitab 17 software to
generate a formula for calculating the moment redistribution.
The FE results showed a significant improvement in the moment redistribution when
both top and bottom reinforcement are over-reinforced. Also, the results showed that
BMFs have positive effect on the moment redistribution. On the other hand, it revealed
that there is no significant effects of stirrups spacing on the moment redistribution. |
