The effect of using nanomaterials on the durability of concrete / Marium Mohamed Fathi Mohamed Mahmoud Eid ; Supervised Osama Abd ElGhafour Hodhod , El Saaid Ibrahim Zaki

Thesis (M.Sc.) - Cairo University - Faculty of Engineering - Department of Civil Engineering

Studies have highlighted the potential use of pozzolanic materials formed naturally or existed as by-product as supplementary cementing materials (SCMs) in micro or nano size because substitution of cement partially can enhance concrete{u2019} mechanical properties. Hence, production of cement which is considered one of the main sources of carbon dioxide emission and energy intensive can be minimized. Definition of durability of concrete as per American Concrete Institute (ACI) Committee 201 can be given as its resistance to the action of weathering; the attack by chemicals, and the process of abrasion or any other deterioration processes. The degree of durability differs from one concrete to other due to environmental exposure and desired properties. There are many measurements that can determine efficiency of concrete durability such as mechanical strength, aggressive media resistance, fire exposure resistance, creep, shrinkage and permeability. This thesis aims to study the effect of using nano materials such as nano Bentonite (NB) and hybrid nano particles of two different materials such as nano Kaoline (NK)+ nano Bentonite NB on concrete durability due to normal and aggressive condition. Different mixes of test cubes 10x10x10 cm were made with various amounts of NB of percentage 10%, 15%, 20%, 25% and 30% partial substitution of cement by weight. First samples group (15 test cubes) were subjected to normal curing and tested after (7, 28, 60, 90 and 180 days), while the second group of samples (15 test cubes) were subjected to sulfuric acid of concentration 0.2 N where N is the normality of Sulfuric acid H2SO4) and tested after the same ages. Concrete specimens (18 test cubes10x10x10 cm) using hybrid Nano particles of NK and NB of percentage 10% and 12% and 14% respectively as partial substitution of cement in terms of weight using (40% NK and 60% NB) were cast. 50% of the samples were exposed to normal curing and the rest of samples were exposed to aggressive curing same as NB samples. All samples were prepared in Laboratory and results were compared to control mix. To evaluate the permeability coefficient 5 cubes 15x15x15 cm with various different percentages of NB and 3 cubes 15x15x15 cm of hybrid (NB+NK) were cast and tested.

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