الفهرس 
CHAPTER 1 INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Concrete is one of the most popular extensively used construction materials in the world. The concrete industry produces approximately 12 billion tones of concrete and uses about 1.6 billion tones of Portland cement worldwide each year, locally, the annual production of cement in Egypt was 42.8 million ton at 2016, while the consumed electric power was 18.9% of the total consumed energy in the industrial production activities, and the consumed fuel in the cement industry was 36.1% of the total consumed fuel in the industrial production activities, according to the latest statistics issued by Central Agency for Public Mobilization and Statistics. Portland cement production is one of the most energy intensive of all industrial manufacturing process. Portland cement is not only the most energy intensive materials of construction but it is also responsible for large amount of greenhouse gas (carbon dioxide). the manufacture of one ton of cement approximately 1.0 ton of CO2 are launched into the atmosphere. The cement industry account for 5-8% of worldwide CO2 emission. To reduce the environmental impact of cement industries metakaolin and other pozzolanic materials are used to replace part of cement. Using the metakaolin in the concrete industry has received considerable attention in the recent years. Although Egypt have a large reserve of kaolin , the metakaolin is not widely produced and used in the concrete industry due to the lack of adequate local experiments and studies. The objectives of the study are: investigate the effect of using the metakaolin on the fresh and hardened concrete mixes, identify the optimum replacement of metakaolin to the concrete mixes, compare the performance of the metakaolin with the silica fume, studying the environmental impacts of using the metakaolin considering the consumed energy and CO2 release comparing to Portland cement. The study was carried out in two parts, the first part practical and divided into three phases, the first phase is to obtain the metakaolin from a local source and to verify the calcinations process of kaolin through the mineral composition using X-ray diffraction (XRD) test, the chemical composition using X-ray flurescence (XRF) test and particle size analysis test were carried out to compare with the standard specifications requirement, the second phase is to investigate the effect of using metakaolin as a cement partially replacement with ratios from 0 to 20% on the properties of the fresh and hardened concrete mixes, the third phase is to investigate the effect of using metakaolin as a mineral additive with addition ratios from 0 to 15% on the properties of the fresh and hardened concrete mixes. Slump test of the different concrete mixes conducted to explore the effect of incorporating metakaolin on fresh concrete properties. Compressive strength test, splitting tensile strength test and flexural strength test conducted to investigate the effect on hardened concrete properties. The second part is theoretical by analyzing data and test results and comparing with the reference concrete mix and silica fume mix, then studying the environmental impact of using the metakaolin in concrete in terms of carbon emission and energy consumption. The experimental results showed using the local metakaolin is considered an effective pozzolanic materials enhanced the workability of the fresh concrete at the used w/c = 0.56, superplasticizer dose 1.77%, and enhanced the mechanical properties of the metakaolin concrete compared to the control mix and nearly the same as silica fume mix. The optimum replacement level of the cement with the metakaolin was 15%. The enhancing in the concrete compressive strength was 10%. The optimum dosage of metakaolin as a mineral addition to the concrete mix was 15% of cement content (compared to 5% and 10%). The environmental benefits are reducing CO2 emissions with 12.38% and energy saving with 5.56% compared to that control mix. At present the market price of silica fume is about 7" ~ "8 times that of metakaolin, therefore using of metakaolin provides major economic benefits compared to silica fume.