الفهرس 
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Abstract
Concrete is considered the main component in the field of building and construction, and the most important characteristics that distinguishes it, its high compressive strength, durability and also availability. The most important component involved in the concrete industry is Portland cement, which is the basis for its manufacture Cement (PC) manufacture produces a considerable amount of carbon dioxide emissions, as 1 ton of cement releases more than 1 ton of carbon dioxide CO2, and that huge amount of CO2 increase temperature and aid in global warming. Cement also consumes for its industry great amounts of energy and raw materials like limestone. There are solutions that have been suggested for the purpose to make eco-friendly concrete to save natural resource and reduce the use of energy in cement industry to decrease CO2 emissions. Geopolymer concrete (GPC) is a new special type of concrete which is eco-friendly construction material that produced by totally replacing the PC and also it is considered as the 3rd generation of binders, following PC and lime. Many researchers believe that the Geopolymer concrete will be the future concrete because of the absence of cement in its mixtures as cement could be totally replaces with a pozzolanic material like Fly Ash (FA) and activated by an alkaline solution. The use of GPC still limited in the construction field because it is difficult to control the heat curing in site. And going with the way to decrease the unit weigh of the concrete, it is possible to create concrete with density under 2000 kg/m3, as lightweight concrete can help to reduce the impact of the force caused by earthquakes on buildings and it can improve thermal insulation and sound absorption. It can be prepared by using lightweight aggregates like pumice stone or adding foaming agents like aluminum powder or air entraining admixtures. This thesis studies the effect of pumice stone and aluminum powder (AP) on geopolymer concrete to create lightweight and foamed concretes and mortar. Pumice stone is added as a coarse aggregate for light weight geopolymer concrete mixtures with 70%, 65% and 60% of the total weight of the aggregates of each group of mixtures which are three groups. Aluminum powder was added as an admixture to foamed geopolymer mixtures with the following ratios to FA (0.2%–0.4%–0.6%–0.8%–1%–1.2%–1.4%–1.5%). To study the properties of fresh, hardened concrete, durability and unit weight, fresh properties were studied by slump test for concretes prepared with pumice stone and slump flow for mixtures prepared with aluminum powder. The mechanical properties were investigated by compressive strength, splitting tensile strength for all mixtures and flexure strength for concrete mixtures. IV Durability properties were investigated by applying heigh temperatures at 200℃, 400℃, 600℃ and 800℃ to obtain the residual compressive strength and the percentage of the weight loss after exposing samples to the mentioned elevated temperatures, ultrasonic pulse velocity (UPV), permeability and sorpitivity. And through the aforementioned tests, it was concluded that the lowest value of slump was equal 150 mm at (M 1-1) for mixtures in which pumice stone was used as a coarse aggregate and for the slump flow, the smallest value was 55 mm for foamed concrete mixtures with aluminum powder and 105 mm for mortar mixtures prepared using aluminum powder. For the dry density and mechanical properties, mix (M 3-3) achieved the lowest dry density=1654 kg/m3, through mixtures prepared with pumice stone, while mix (M 1-1) is the mixture that has the greatest values all over the mixtures prepared with pumice stone, as its dry density = 1826 kg/m3, compressive strength = 21.7 and 24.2 MPa after 7 and 28 days respectively, splitting tensile strength = 3.88 MPa, and flexure strength = 1.8 MPa. Moving to foamed mixtures, aluminum powder dose of 1.5% FA (the biggest percent of AP) for the both concrete and mortar mixtures gave the smallest dry density with 1821 and 1600 kg/m3 for concrete and mortar respectively, while when AP = 0.2% FA (the biggest percent of AP), mechanical properties achieved their greatest values for the both foamed concrete and mortar, as compressive strength for foamed concrete = 14 and 17 MPA after 7 and 28 days respectively, 11.6 and 13 MPa for foamed mortar mixtures after 7 and 28 days respectively. Splitting tensile strength = 2.86 and 2.375 MPa for foamed concrete and mortar respectively, and flexure strength = 1.378 MPa for foamed concrete. Then, by moving to the durability properties, the tests showed that, for the elevated temperature test, the residual compressive resistance showed for pumice stone mixtures, compressive strength for all mixtures increased than their values after 28 days after exposing to all elevated temperatures except mix (M 3-3), its compressive strength after exposing to 800℃ reduced than after 28 days. But this did not happen in foamed mixtures, whether it was concrete or mortar, as in foamed concrete mixtures, by exposure to elevated temperatures, compressive strength after exposure to 200℃ increased from its value after 28 days, and after exposure to 400℃, compressive strength increased than its value after 28 days for mixtures with the highest percent of aluminum powder (M 1.2 – M 1.4 – M 1.5) with residual compressive strength (105.4% – 106.6% – 108.1%) respectively and decreased at the rest of mixtures, and then decreased also for all mixtures after exposure to 600℃ and 800℃. And in foamed mortar mixtures, by exposure to elevated temperatures, compressive strength after exposure to 200℃ increased from its value after 28 days for all mixtures but after exposure to V 400℃, compressive strength for the following mixtures also increased than their values after 28 days (M (0.2m), M (0.4m), M (0.6m) and M (0.8m)) with residual compressive strength equals 112.3%, 104.16%, 112.1% and 110% respectively. Moving to UPV test that was made to know the quality of each mixture, for pumice stone mixtures, the best mixtures were (M 3-3), followed by mix (M 2-3), followed by mix (M 1-2), as these mixtures have the lowest content of pumice stone. The best mixture for foamed concrete was mix (M 0.2), it was excellent mix as it has the less pores, and the best mixture for foamed mortar samples was mix (M 0.2m) because it contains the less voids. For the permeability test, when applied to pumice stone mixtures results showed that mixtures that contain the greatest percent of pumice stone which is a permeable material are the mixtures has the greatest value of permeability, these greatest values are 10, 9.4 and 9 mm for the mixtures M (1-1), M (2-1) and M (3-1). But all mixes with aluminum powder whether it was concrete or mortar were fully penetrated with water for all aluminum powder percentages. And finally, for sorbitivity test, results showed for pumice stone samples, samples in case of greatest percent of pumice stone exhibited the greatest sorptivity than other mixtures. And for foamed concrete and mortar, it is noticed that with the increase of AP percent, sorpitivity increases.