الفهرس 
Semi-Flexible PavementOnly 14 pages are availabe for public view
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Abstract
The most common pavement that is widely used is flexible bituminous pavement or also known as asphalt pavement. It consists of asphalt as a binder mixed with a certain aggregate gradation to form a durable surface material lay down to sustain traffic loads. Bitumen is flexible and elastic which is why the total pavement structure deflects under loading. Asphalt supply in the Egyptian market decreases due to the increasing volume of road construction projects in the current decade. Consequently, increasing the local asphalt prices. Another problem has been observed on many newly constructed Egyptian roads, that is the rutting distress due to the increasing of the axle loads accompanied by the increasing of goods. On the other hand, rigid pavement performance for resisting rutting is the best while the construction cost of it is more than the flexible pavement. In addition to the long-time which concrete pavement take to establish and maintain. The ideal solution of all these problems is to have a wearing course handling these issues. Thus, this solution is having asphaltic mixtures with lower asphalt content and high resistance to the rutting distress. This study aims to design special type of surface layers with these needs. The construction of new pavements is the need of nowadays in all over the world. This work introduces a surface layer which consists of semi-flexible
material. This new pavement provides advantages of other pavement types like concrete pavement and asphalt pavement. Such type of pavement has a good resistance to percolation of water to the foundation as the surface course becomes impermeable. Such type of pavement is called as a semi-flexible pavement (SFP) or grouted macadam (GM) or resin modified pavement (RMP). This pavement should be properly studied in order to use it for pavement construction. To achieve the aim of study, grouting technique of highly permeable asphalt mixtures was used. Crushed siliceous-limestone and limestone, and silica-lime filler were used to prepare highly permeable asphalt mixtures. Asphalt contents of these mixes were determined theoretically and checked visually in laboratory. Marshall stability, Marshall flow and indirect tensile strength tests were conducted to define grouted asphalt mixtures properties. The same tests were conducted on crushed siliceous-limestone open-graded surface mix of (2C) gradation (Egyptian Standards for Roads) for comparison purposes. Prisms representing grout mixes were prepared by using ordinary Portland cement (OPC) and crushed fine sand as well as some concrete additives with different ratios. Silica fume, fly ash used as powder solid case. Despite, superplasticizer was added as a liquid. These additives were used for improving the grout performance (strength and workability). Water was used for mixing all the solid grout materials. By analyzing the study results, positive effect of grouting technique using a mixture of (1:1) OPC to crushed fine sand with adding small percent of silica fume and superplasticizer is concluded. Grouted asphalt mixtures require asphalt content less than the required percent for ungrouted open asphalt mixtures (mix 2C). It also achieves improvement of rutting resistance through increasing stability and indirect tensile strength (ITS) by about three times and more compared to open asphalt mixtures.