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.
A New Vacuum Pressure Infiltration CFRP Method and Preparation Experimental Study of Composite
In order to prepare a carbon-fiber-reinforced polymer composite (CFRP) with ideal microstructure and properties, a new vacuum pressure infiltration CFRP method is proposed based on an analysis of existing CFRP preparation process methods. Research on composite material preparation systems was carried out by using this new method principle. The system mainly includes a fiber pre-forming module, a vacuum heating infiltration module, a hot-press curing molding module, and a data acquisition control module. Under the conditions of natural curing at 0 MPa + 6 h + 25 °C, vacuum heating curing at –0.05 MPa + 30 min + 80 °C, and hot-press curing at 0.7 MPa + 5 min + 50 °C, a two-dimensional (2D) CFRP with excellent microstructure and properties was successfully prepared. Observing the microstructure of the prepared composite material, it can be found that the inside of the composite material was sufficiently and uniformly infiltrated, and common preparation defects such as holes and delamination were effectively controlled. Through the performance test, the bending strength of the material reached 790 MPa.