Rutting and Fatigue Cracking Susceptibility of Polystyrene Modified Asphalt

Abstract

Abstract:The absence of studies investigating the influence of waste Polystyrene (PS) on the performance characteristics of rutting resistance and fatigue cracking resistance of the indigenous asphaltic materials Trinidad Lake Asphalt (TLA) and Trinidad Petroleum Bitumen (TPB), has hindered the possible use of PS as a performance enhancer as observed with other asphalts from different sources thus also developing a sustainable approach for the disposal of PS. The influence of PS on TLA and TPB was investigated by measuring the rheological properties of complex modulus (G*) and phase angle (δ) of prepared blends and calculating the fatigue cracking resistance and rutting resistance parameters (G*sin δ and G*/sin δ respectively). The addition of PS to TLA resulted in an increase in the fatigue cracking resistance as well as the rutting resistance compared to the pure TPB binder. Despite having improvements in rutting resistance due to PS addition, the fatigue cracking resistance of the TPB parent binders were superior compared with the PS modified TPB blends. The incremental increase in temperatures for TPB and TLA based blends resulted in gradual improvements in their fatigue cracking resistances but gradual deterioration in the rutting resistance of the modified blends. The conclusions were identical for both the Research Program Super pave specification and the Strategic Highway Research Program specifications. There is strong rheological evidence of the possibility to utilize waste PS as an asphalt performance enhancer for both TLA and TPB thus creating a sustainable strategy for the reuse of waste PS.

Modification of Asphalt Binder with Waste Expanded Polystyrene (EPS) Foam

“…PS foam represents 70% of the total plastic waste in the oceans due to its low recycling rate. Approximately 3 million tons of PS waste are threatening the environment due to their chemical stability [5][6][7][8]. Although this threat is tried to be eliminated through landfills and incineration, landfill brings an extra cost, and incineration results in toxic gas emissions, which is detrimental to the environment [5].…”

“…Polymeric materials are also considered a good bitumen modifier because of their chemical structure composed of mostly carbon elements [7]. Thus, many studies have been done on asphalt modification with polymeric materials such as PP [9], PE [10], and PS [8,[11][12][13][14]. For instance, Vila-Cortavitarte et al (2018) has performed a life cycle assessment on waste PS modified bitumen and they suggest that using modified bitumen might reduce its environmental impact significantly because it provides longer performance life [14].…”

The performance and durability of polyethylene terephthalate and crumb rubber–modified road pavement surfaces

“…16 The use of waste polymeric wastes to possibly improve asphalt pavement performance while simultaneously solving the environmental problem associated with disposal has been receiving research attention with encouraging results in Trinidad and Tobago. 3,5,17 -21…”

“…3 TLA has been internationally well established as a commercial product and a source of superior quality asphalt (due to its consistent properties, resistance to cracking, stability and durability compared to other asphaltic materials) and is often specified as a mandatory ingredient for paving in high demand situations such as those encountered in airport runways. [4][5][6] Research has shown that the unique fractional, chemical and functional group composition of TLA determines its strength, durability and resistance to ageing and weathering. 2,3 Asphalt's most valuable and widespread usage is for that of paving.…”

“…16 The use of waste polymeric wastes to possibly improve asphalt pavement performance while simultaneously solving the environmental problem associated with disposal has been receiving research attention with encouraging results in Trinidad and Tobago. 3,5,[17][18][19][20][21] A serious issue of national importance in Trinidad and Tobago in recent times has been the uncontrollable usage and disposal of crumb rubber (CR) from used vehicle tyres and polyethylene terephthalate (PET) from beverage containers. An article in the Trinidad Express Newspapers on 1 October 2013 stated that Trinidad and Tobago was on the verge of licensing the country's millionth car.…”