الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
In the last years, researches succeed in producing light weight concrete with purpose of reduce the dead load of structural elements, thus reducing the costs of whole structure through allowing the designer to reduce the dimensions of structural elements and therefore reducing the amount of steel reinforcing, as well as improving the purposes of thermal and acoustic insulation.
Light weight concrete can be produced by one or more of the following methods such as producing finless concrete that consists of cement, water and coarse aggregate. Another method is by using lightweight aggregate, or by inserting gas or air bubbles into concrete mixture or adding foam materials for the mixture. In this study, lightweight concrete is produced by using zeolite as an aggregate and bubble generating agent by heated zeolite sample for 2 hr at ᵒC. and study the effect of calcined zeolite on the properties of light weight concrete. where zeolite has pozzolanic characteristics and can improve the properties of concrete. Many researchers have conducted deep studies on how to enhance the properties of concrete and reported that using pozzolanic materials proved to be effective in promoting its strength due to their pozzolanic reaction which reacts with excess calcium hydroxide (CH) forming extra calcium silicate hydrate (C-S-H) gel which enhances the interfacial transition zone (ITZ) among aggregates and cement blends resulting in promoting concrete strengths. Zeolites are crystalline alumina silicates with uniform pores, channels and cavities, this cavities occupied by cations of different elements. In this study, coarse aggregates were replaced with coarse zeolite larger than or equal to 5 mm and fine aggregates were
replaced with fine zeolite less than 5 mm. and thus concrete contains cement, water, superplasticizer and zeolite (coarse and fine). A laboratory study was conducted to determine the effect of zeolite on the production of lightweight concrete on both the properties of fresh concrete (by produce test of workability).and the properties of hardened concrete (by produce tests such as compressive strength, tensile strength, flexural strength, bond strength, sorpativity test , ultrasonic pulse velocity . Using different percentages up to The results have shown several important conclusions. Usage of calcined zeolite decreases the unit weight of concrete. Relatively lower specific gravities (2.1) pore structures of zeolite could be attributed to unit weight reductions. As well as the ability of zeolite to generate bubbles within the concrete mix. And showed improvement in physical and mechanical properties when increase the amount of coarse aggregates (coarse zeolite) and reduce the amount of fine aggregates (fine zeolite). Compressive strength, flexural strength, tensile strength and bond strength. And therefore affects the strength negatively. Results of compressive strength showed that Zeolite has high pozzolanic effect where the ratio between compressive strength at 7 days and 28 days was 2.7 and the ratio between compressive strength at 90 days and 28 days was 1.27.
Key Words: Natural zeolite, clinoptilolite, Light Weight Concrete, Compressive strength, flexural strength, tensile strength, bubble generating.