Influence of Microcrack Healing Techniques on Tensile Strength of Asphalt

Abstract

Asphalt concrete pavement practices repeated loading and environmental impacts and suffers distresses. Microcracks usually occurs at early stage of pavement life while the pavement can heal itself under controlled conditions. Microcrack healing process can be controlled and accelerated using various techniques. In this investigation, iron filling was implemented as partial substitute of sand to support the healing process while both induction and external heating techniques were adopted to control the healing using microwave and oven. Asphalt concrete specimens have been prepared with different percentages of iron filling and the corresponding required asphalt content. Specimens were subjected to repeated indirect tensile stresses for 600 and 1200 load repetitions. Specimens were allowed to heal using microwave and oven heating techniques. Specimens were subjected to another cycle of stress repetitions and the variation in the indirect tensile strength was detected before and after healing. The healing performance of the asphalt mixture specimens at different healing conditions was investigated by observing and testing the recovery of indirect tensile strength after healing. It was concluded that implementation of iron filling and induction heating by microwave can improve the healing and tensile properties of asphalt concrete as compared to the oven heating technique.

Impact of Plastic Waste on The Volumetric Characteristics and Resilient Modulus of Asphalt Concrete

“…The increase in the Marshall stability value of the mixture is due to adding of plastic particles to the mixture which cause a decrease in the viscosity of the mixture. Similar results were reported by Sarsam & Al Tuwayyij [8]. In Figure 9, the optimal asphalt content (OAC) for each mixture containing a certain percent of plastic particles was computed by taking the average values of asphalt contents at maximum unit weight, maximum stability, and asphalt median air void ratio.…”

“…The material was added in different proportions to study the mechanical properties and RM of asphalt. It was found that 5% yields the best results by improving asphalt concrete sample stability and flow values, as well as showing the highest RM value [7,8]. An investigation of developing asphalt properties by incorporating plastic waste for road pavement construction was conducted.…”