الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Cement concrete is the most extensively used construction material. In this view waste materials disposed from industries and or pozzolana materials containing reactive silica or alumina are used in cement. Metakaolin looks to be a promising supplementary cementitious material for high performance concrete. Cement is a popular material in construction all over the world but Carbon dioxide emission is the largest atmospheric pollutant of cement. Therefore, researchers must develop new materials, such as an alternative to cement such as supplementary cementitious materials, SCM.
The experimental test program was designed to achieve the research objectives of study. The program consists of two phase.
Phase I was designed to produce concrete mixes for Normal Concrete, concrete with flay ash, silica fume and concrete with matakaolin , in different content of cement.
Phase II was designed to produce concrete mixes for High performance Concrete, concrete with flay ash, silica fume and concrete with matakaolin , in different content of cement .
In the experimental work, the fresh concrete properties (slump test) and the hardened concrete properties (compressive strength, tensile strength, flexural strength, modulus of elasticity and permeability) were carried out. A total of teweenty six concrete mixtures were performed with different cement contents of 300Kg/m3 or 500Kg/m3 at W/C = 0.3 , the amount of water was adjusted according to cementitious materials content ( cement + fly ash , silica fume or metakaolin) ,the superplasticizer dosage was added by weight from cementitous materials ( cement + fly ash or metakaolin) to achieve the required level of workability defined by a slump value of 10± 2 cm.
At this experimental works, cement is replaced by (0%, 5%, 10%, 15% and 20%) from metakaolin or silica fume or fly ash by weight of used cement. The content of cementitious materials in all mixes for Phase I was used 300Kg/m3, for Phase II was used 500 Kg/m3 and the water/binder materials ratio (w/b) equal 0.3. Performances of metakaolin mixes were compared with control mix, silica fume mixes and fly ash mixes. Mk concrete mixes showed a better consistency than other mixes of experimental program. The compressive strength and other hardened properties of concrete with Mk were higher than that of reference concrete.
The test results showed that a FA content or SF content of about 15% by replacement of cement gave concrete with the optimum strengths. The test results showed that a Mk content of about 10% by replacement of cement gave concrete with the optimum strengths. As the replacement levels was increased, the mechanical properties of the silica fume concrete increased at all ages similarly to that of the metakaolin and fly ash concrete.
The results showed that using Mk in concrete mixes increased the residual compressive and flexural strength after exposure to elevated temperatures than mixes containing SF or FA. The results showed that the replacement materials to all mixes improves the performance of the produced blended concrete when exposed to elevated temperatures up to 100 oC. SF concrete mixes showed a better compressive strength after immersion in sodium sulfate solution at 28, 90 and 150 days than Mk, FA and control concrete mixes.