الفهرس 
Chapter (1) IntroductionOnly 14 pages are availabe for public view
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Abstract
Bituminous mixes are most commonly used all over the world in flexible pavement construction. Bituminous mixtures consist of asphalt or bitumen (used as a binder) and mineral aggregate which are mixed together, laid down in layers and then compacted. Under normal circumstances, conventional bituminous pavements – if designed and executed properly – perform quite satisfactorily but the performance of bituminous mixes is very poor under various situations. Today’s asphaltic concrete pavements are expected to perform better due to the daily increase in volume traffic, increased loads and increased variations in daily or seasonal temperature over what has been experienced in the past. In addition, the performance of bituminous pavements is found to be very poor in moisture induced situations. Considering this, a lot of work has been done on use of additives in bituminous mixtures and modification of bitumen. Researchers have indicated that the addition of polymers to asphalt binders helps to increase the interfacial cohesiveness of the bond between the aggregate and the binder which can enhance many properties of the asphalt pavements to help meet these increased demands. However, the additive that is to be used for modification of mix or binder should satisfy both the strength requirements as well as the financial aspects.
Plastic wastes are everywhere in today’s lifestyle and are growing rapidly specially in a developing country like Egypt. As these are non-biodegradable, there is a major problem posed to the society with regard to the management of these plastic wastes. The reclaimed plastics originally made of polymers. Low-density polyethylene (LDPE) and high-density polyethylene (HDPE) have been observed to modify bitumen. In the present study, an attempt has been made to use recycled plastic wastes in wet form – mixing as a percentage of the total mixture weight – with the aggregates in its liquid status. Detailed study on the effects of these locally wastes on bituminous mixes has been made in this study.
The polyethylene additions are used as stabilizer in hot mix asphalt (HMA) mixes to fulfil the desired requirements of paving mixes. Optimum bitumen content and optimum polymer content have been derived by using Marshall procedure. Considering optimum bitumen content and optimum polymer content, the HMA mixes have been prepared and different performance tests like static indirect tensile strength test (IDT), moisture damage test, dynamic modulus test, and flow number test have been carried out to evaluate the effects of polymers as a stabilizer on mix properties. It is concluded from present study that addition of polymers to mixes improve the mix properties like stability, shear strength and permanent deformation.