Loading...
Search for:
compaction-temperature
0.01 seconds
Evaluating the effects of Sasobit on characterization and workability of asphalt mixes containing reclaimed asphalt binders
, Article Asphalt Pavements - Proceedings of the International Conference on Asphalt Pavements, ISAP 2014 ; Vol. 2, issue , 2014 , p. 1241-1252 ; Vahabi, A ; Sharif University of Technology
Abstract
Use of Reclaimed Asphalt Pavement in HMA1 is beneficial by reduction of initial costs. But the higher stiffness of aged binder may lead to workability issues in the field, therefore use of large percentages of RAP2 impacts the HMA properties. Utilizing Sasobit is a solution to use more RAP at a relatively lower temperature in HMA mixes. This study investigates the effects of 2 percent Sasobit on the reduction of compaction temperature by measuring low shear viscosity and workability of mixtures containing RAP binder. Low and intermediate temperature properties of RAP binder using mix designs were compared to properties of artificially aged binders. Virgin binder was aged in PAV to make...
Evaluation of Laboratory Methods for Estimation of Mixing and Compaction Temperatures of Rubber Modified Asphalt Mixtures
, M.Sc. Thesis Sharif University of Technology ; Tabatabaee, Nader (Supervisor)
Abstract
One of the major challenges in construction of rubber modified asphalt mixtures is determination of mixing and compaction temperature (MCT). In order to estimate MCT according to Superpave volumetric mix design procedure, a temperature-viscosity relationship for the binder should be developed using ASTM D2493. This approach provides reasonable temperatures for unmodified binders which are Newtonian fluids at high temperatures and their viscosity is independent of shear rate. However, this method often yields excessively high temperatures for modified binders which exhibit non-Newtonian pseudoplastic behavior. The reason is that viscosity of modified binders depend on not only temperature but...
Rutting and moisture resistance evaluation of polyethylene wax–modified asphalt mixtures
, Article Petroleum Science and Technology ; Volume 34, Issue 17-18 , 2016 , Pages 1568-1573 ; 10916466 (ISSN) ; Darbandi Olia, A. D ; Akbari Nasrekani, A ; Asadi, P ; Sharif University of Technology
Taylor and Francis Inc
Abstract
One of the methods newly introduced in pavement technology to address environmental concerns and reduce total gas emission is warm mix asphalt (WMA) technology. In this study, polyethylene wax is used to produce WMA mixtures. Although this technology has several positive features, moisture and rutting resistance of WMA mixtures are always questionable. To evaluate moisture and rutting resistance of polyethylene-modified mixtures, indirect tensile strength and dynamic creep tests were used, respectively. Results indicated that polyethylene has positive effect at low compaction temperature on moisture resistance, and also has negative effect on rutting resistance
Genetic algorithm-based numerical optimization of powder compaction process with temperature-dependent cap plasticity model
, Article International Journal of Advanced Manufacturing Technology ; Volume 64, Issue 5-8 , 2013 , Pages 1057-1072 ; 02683768 (ISSN) ; Khoei, A. R ; Molaeinia, Z ; Sharif University of Technology
2013
Abstract
In this paper, a shape optimization technique is presented for the cold and hot isostatic pressing of metal powders based on the genetic algorithm (GA) approach. The GA technique is used to obtain the desired optimal compacted component by changing the boundaries of component and verifying the prescribed constraints. The coupled thermomechanical analysis of hot isostatic pressing is employed for metal powders during densification process. The numerical modeling of hot powder compaction simulation is performed based on the large deformation formulation, temperature-dependent cap plasticity model, and frictional contact algorithm. The modified cap plasticity takes the temperature effects into...
Design optimization of hot forming process of metal powders via the genetic algorithm technique
, Article Steel Research International ; Volume SPL. ISSUE , 2012 , Pages 799-802 ; 16113683 (ISSN) ; 9783514007970 (ISBN) ; Keshavarz, S ; Molaeinia, Z ; Sharif University of Technology
2012
Abstract
In this paper, a shape optimization technique is presented for hot isostatic pressing of metal powders based on the genetic algorithm approach. The GA technique is used to obtain the desired optimal compacted component by changing the boundaries of component and verifying the prescribed constraints. The coupled thermo-mechanical analysis of hot isostatic pressing is employed for metal powders during densification process. The numerical modeling of hot powder compaction simulation is performed based on the large deformation formulation, temperature-dependent cap plasticity model, and frictional contact algorithm. A modified cap plasticity model considering the temperature effects is used in...