Evaluate the Effect of Waste Ground Rubber Tire Powder in Hot Mix Asphalt
In the present study, the effect of waste ground rubber tire powder (WGRTP) modifier on various mechanical properties such as Marshall stability, flow, Marshall quotient (MQ), bulk specific gravity, air voids, voids filled with bitumen (VFB) and percent voids in compacted mineral aggregates (VMA) of asphalt mixture has been evaluated. The Marshall tests of the polymer modified asphalt mixture, prepared through dry process, indicated the optimum waste polymer modifier content to be 5% by weight of mix. The waste polymer modified asphalt mix containing 5% WGRTP showed considerable improvement in various mechanical properties of the mix compared to the conventional asphalt mixture. The appropriate amount of the added WGRTP was found to be 5% by weight of aggregate. This percentage results in the maximum level of stability. Keywords—Hot mix asphalt; Waste ground rubber tire powder; Dry process; Marshall test method
Effect of polyester resin additive on the properties of asphalt binders and mixtures
Abstract The properties of AC-5 control asphalt binder, mixture containing the same asphalt were compared with the properties of AC-10 asphalt binder modified by 0.75%, 1%, 2%, and 3% of polyester resin (PR), mixture containing pure AC-10 and AC-10 modified by 0.75% of PR, respectively. Initial research was done to determine the physical properties of unmodified and PR modified asphalt binders. The AC-10 asphalt binder modified by 0.75% of PR had good results compared to AC-5 control asphalt binder and all other modified binders, and hence this modified binder as well as unmodified binders were used to prepare Marshall samples for Marshall stability and flow, indirect tensile stiffness modulus (ITSM), indirect tensile strength (ITS) and creep stiffness tests. The results of investigation indicate that AC-10 + 0.75% PR binder has better physical properties than AC-5 control asphalt binder and, at the same time, PR improves mechanical properties of asphalt mixture.
The history and development of the dental surveyor--Part III.
The dental surveyor is an indispensable instrument capable of performing a number of prosthodontic procedures. Surprisingly, the technique of surveying casts as part of the treatment planning procedure did not emerge until early in the twentieth century. This article reviews the origins and early use of the dental surveyor. It includes features common to all surveyors as well as the principal uses of these instruments.