eva‎luation of moisture susceptibility and fatigue properties of cold recycled mixtures with polymer modified asphalt emulsion by using conventional tests

10/4/2023 12:00:00 AM

As a result of the increase in the cost of bitumen and the decline in the quality of materials, the use of reclaimed asphalt pavement (RAP) over the past few decades has been more focused than new materials. Although the use of RAP in the pavement industry is well stabilized, research on maximizing the use of recycled materials in construction, reconstruction and maintenance due to environmental issues and increasing the importance of sustainable development in transportation infrastructure projects is still considered. For this purpose, pavement recycling methods such as hot and cold recycling have improved rapidly over the past two decades. While most countries have set restrictions, usually from 10 to 50 percent, the maximum permissible RAP usable in hot mix asphalt (HMA), it is possible to use 100% RAP through cold recycling asphalt pavements. With the development of modified emulsified asphalt, the cold recycling method has the potential to be used in pavement layers near the surface. Cold recycling is a way to recycle RAP using bitumen emulsion and additives such as cement without the application of heat. This method includes many economic and environmental benefits including energy and materials. In this study, Styrene–butadiene rubber (SBR) latex and polyethylene glycol (PEG) were used to modify the bitumen emulsion. The results of the Lattman modified moisture sensitivity test demonstrated that the use of latex SBR polymer increased the resistance of cold recycling mixture against moisture damage by more than 8%, while PEG reduces moisture resistance. The results of the diameter fatigue test (IDT) also showed that the use of these polymers increased the life of the cold recycling mixture which is significantly higher for the SBR latex. The best performance belonged to cold recycle mixture with 4% SBR latex which extended the fatigue life of the mixture at two levels of stress of 400 and 500 kPa, respectively, 23 and 13 times more than the control mixture.

بازيافت سرد , قير امولسيوني اصلاح‌شده‌ي پليمري , خستگي , حساسيت رطوبتي , SBR لاتكس , پلي اتيلن گليكول (PEG)

Cold recycling , Polymer modified bitumen emulsion , Fatigue , Moisture susceptibility , SBR latex , polyethylene glycol (PEG)

Omid Asadi

Dr. Hasan Ziari