الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Concrete is the key building material used for construction activities and
development projects throughout the world. Portland cement is ordinarily used as
the main binder to produce concrete; however, it is not an enviro-friendly material
as the production of Portland cement depletes natural resources and results in the
emission of a large amount of greenhouse gases. Therefore, geopolymer concrete
(GPC) has received considerable attention in recent years because of its
significant environmental benefits where it utilizes solid industrial
aluminosilicate-based waste materials, such as fly ash (FA), rice husk ash, silica
fume, or ground granulated blast furnace slag (GGBFS) to produce a low-cost
and environmentally friendly material as an alternative to Portland cement. Heatcured
GPCs have been studied extensively to establish their properties and it has
been found that they can achieve comparable and, in some cases, better properties
than ordinary Portland cement concrete. However, very few attempts to assess
the properties of ambient-cured GPC are reported in the literature.
The main objective of this research is to investigate the efficiency of using ecofriendly
pozzolanic materials (GGBFS + FA) to create GPC under ambient curing
conditions and investigate the effect of main parameters on the fresh, hardened,
and durability characteristics of the produced GPC.
The experimental program consists of two main phases: the first phase
investigates the fresh and hardened properties of ambient-cured GGBFS-FAbased
GPC. Nine mixes (designed by Taguchi method) were carried out
considering the four most effective parameters: GGBFS to FA ratio, binder
content, sodium silicate (SS) to sodium hydroxide (SH) ratio, and activator
molarity (M). Slump test was conducted to investigate the workability of fresh
concrete while compression test, splitting test, and flexure test were conducted to
investigate the hardened properties. The second phase investigates the durability
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characteristics (sulphate acid resistance, water absorption, and chloride
penetration) throughout carrying out six mixes considering the effect of
GGBFS:FA ratio and SH (M).
The experimental results of the first phase showed that using GGBFS as 100% of
binder content could increase the mechanical properties at the expense of
workability which can be improved using fly ash as a ratio of binder content.
However, the test results of the second phase showed that increasing the
proportion of GGBFS content compared to FA content as well as utilizing the
lower SH (M) lead to enhancing the microstructure and the homogeneity of the
GPC, therefore enhancing the durability of the GPC In contrast, increasing FA
content leads to increase in sulphate resistance.
Keywords: Mechanical Properties; Geopolymer concrete; Slag; Fly ash;
Ambient curing; Taguchi method