Investigating the Effect of Softening Agent on the Performance Characterization of Asphalt Concrete Mixture with High RAP Content

, M.Sc. Thesis Sharif University of Technology Majidifard, Hamed (Author) ; Tabatatabee, Nader (Supervisor)

Abstract

Recycling of asphalt pavements has received much attention in recent years for its environmental and economical benefits. Because of increase in costs of raw materials and energy carriers, reuse of a high portion of reclaimed asphalt pavements (RAP) eliminates an enormous amount of waste and reduces the cost of hot-mix asphalt (HMA) mixtures. There are some problems in high-RAP mixtures such as high content of fine aggregate and filler, low temperature cracking potential because of higher stiffness of RAP binder, and low mixture workability. In this research, RAP fractionation was used to sort out and eliminate fine aggregate and filler. An organic-based softening agent was used to improve...

Crack Performance Evaluation of Asphalt Mixtures Containing Laboratory-Prepared Reclaimed SBS/CR Modified Asphalt Pavement

, M.Sc. Thesis Sharif University of Technology Jafarmilajerdi, Amir (Author) ; Tabatabaee, Nader (Supervisor)

Abstract

Cracking is one of the most important distresses in RAP mixtures. One of the common approaches to remedy this problem is to use crumb rubber (CR) and styrene-butadiene-styrene (SBS) for binder modification. Over time, many asphalt pavements containing modified binders reach the end of their service lives and need to be overlaid.This study evaluated the effects of binder modification and aging on the cracking performance of asphalt mixtures. Two long-term aging levels (placing the loose mixture in an oven for 3 or 6 days at 95 degrees Celsius) were considered for investigating the effects of aging on the cracking performance of asphalt mixtures and producing laboratory-prepared artificial...

Post-Earthquake Damage Assessment of Structural Walls Using Image Processing and Machine Learning Techniques

, Ph.D. Dissertation Sharif University of Technology Asjodi, Amir Hossein (Author) ; Mohtasham Dolatshahi, Kiarash (Supervisor)

Abstract

The main objective of this research is to use the visual features of damage in evaluating the post-earthquake status of the damaged structures. Structural health monitoring, as a comprehensive approach, includes methods for identifying the damaged structures, estimating damage location, measuring damage extent, and methods for reconstructing and repairing structures. The present study is specifically focused on the second and third stages of structural health monitoring, including “estimating the location of damage” and “measuring the extent of damage”. Various methods for evaluating the condition of earthquake-damaged structures are available in technical literature; one of the most common...