الفهرس 
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Abstract
Geopolymer concrete is a special type of concrete with no cement content in the
mixture. Since the manufacture of cement requires much energy and produces an
immense amount of carbon dioxide gas causing serious environmental harm, therefore
adopting the use of geopolymer concrete is considered an environmentally friendly and
sustainable construction approach. This thesis addresses geopolymer concrete cast and
cured at room temperature, with the aim of investigating experimentally and
numerically the structural behavior of geopolymer concrete beams and the possibility
of enhancing the flexural behavior through use of different reinforcement schemes and
ratios. An experimental program was conducted where mixes were designed and cast
for traditional and geopolymer concrete prepared at room temperature, then laboratory
determination of the mechanical properties was carried out. Ten beams having
dimensions 2000x250x150 mm, were cast consisting of two traditional concrete beams
and eight geopolymer concrete beams with different reinforcement systems and ratios:
steel bars, glass fiber-reinforced polymer (GFRP) bars, as well as addition of steel or
polypropylene fibers to the mix. The beams are tested in four-point bending until
failure; results and observations regarding deflections, cracking loads, ultimate loads,
crack pattern and failure modes are presented and discussed. Further, numerical
modeling and nonlinear analysis are made for the experimentally tested beams using
the commercial software ANSYS 2021-R1 and analytical evaluation is made for the
beams ultimate flexural capacity. The research findings demonstrate that production of
geopolymer concrete cured at room temperature is a promising strategy for reducing
the consumption of cement, thereby considered beneficial to the environment. The
ductility was generally improved for geopolymer concrete beams compared to normal
reinforced concrete beams, though slight increase of ultimate load by 8.78% and 1.54%
was obtained for geopolymer concrete beams reinforced with steel of GFRP bars,
respectively, compared to normal concrete beams. Geopolymer beams reinforced by
GFRP bars showed more crack formed and wider cracks than steel reinforced
geopolymer beams, the crack width and ultimate load increase with increase of GFRP
reinforcement ratio. Addition of dispersed steel or polypropylene fibers increased the
failure load of GFRP-reinforced geopolymer concrete beams by 10.49% and 8.10%,
respectively. The numerical results showed close agreement with the experimental results, validating the adopted numerical modeling approach and encouraging its
application for analysis and design of sustainable geopolymer concrete beams.
Keywords: Geopolymer concrete; RC beams; GFRP reinforcement; numerical modeling;
finite elements; ANSYS.