The Use of Polyethylene in Hot Asphalt Mixtures

Abstract

The increase in road traffic during the last two decades in combination with an insufficient degree of maintenance due to shortage in funds has caused an accelerated and continuous deterioration of the road network in Jordan. To alleviate this process, several types of measures may be effective, e.g., securing funds for maintenance, improved roadway design, use of better quality of materials and the use of more effective construction methods. The use of polymer in asphalt mixture as a modifier started in the 80s of the last century and has been tested in a number of countries around the World. In this research, polyethylene as one sort of polymers is used to investigate the potential prospects to enhance asphalt mixture properties. The objectives also include determining the best type of polyethylene to be used and its proportion. Two types of polyethylene were added to coat the aggregate [High Density Polyethylene (HDPE) and Low Density Polyethylene (LDPE)]. The polymers were introduced to the mixture in two states (Grinded and not Grinded). Marshall mix design was used, first to determine the optimum bitumen binder content and then further to test the modified mixture properties. In total, 105 samples were prepared (21 samples were used to determine the binder content and the remaining samples were used to investigate the effect of modifying the asphalt mixtures). The optimum asphalt content was 5.4%. Seven proportions of polyethylene of each type and state by weight of the optimum binder content were selected to be tested (6, 8, 10, 12, 14, 16 and 18%). The tests include the determination of bulk density, stability and flow. Marshall mix design requires the determination of the percentages of air voids and air voids of mineral aggregate. The results indicated that grinded HDPE polyethylene modifier provides better engineering properties. The recommended proportion of the modifier is 12% by the weight of bitumen content. It is found to increase the stability, reduce the density and slightly increase the air voids and the voids of mineral aggregate

Effect of Using Polymers on Bituminous Mixtures Characteristics in Egypt

“…(5-d) shows a decrease of flow for all percents of HDPE except the percents of (3% HDPE and 6% HDPE) show an increase of flow results.This agrees well with the results of the penetration and kinematic viscosity for the HDPE modified binder presented in earlier sections. These results agrees with previous research that HDPE can improve the stability and flow of the HMA up to certain percentages then, negative impact starts to appear [3,5,12].…”

“…Another research reported that the best results were obtained when polymer concentration was kept below 3% for HDPE and above this percent stability decreased [11].Another research used HDPE to coat the aggregate by using dry process. The recommended proportion of the modifier was 12% by the weight of bitumen content [5].Hinislioglu et al reported that HDPE modified asphaltic binders provide better resistance against permanent deformation, because of their higher stability and relatively lower flow. As a result, HDPE modified asphaltic binders were considered to be useful in mitigating permanent deformation in hot climate regions [12].…”

Utilization of Recycled and Waste Materials in Various Construction Applications

“…Uses of recycled plastic in the construction industry include plastic strips to add to soil embankments, which has positive results of increasing the measured strength in reinforcement of soils. HMA mixture has a higher stability, reduced pavement deformation; increase fatigue resistance and provide better adhesion between the asphalt and the aggregate (Awwad and Shbeeb, 2007). Grinded polyethylene to provide better coating or attached easily to the aggregate as the surface area of the polymer increases.…”

Utilization of Recycled Polyethylene Terephthalate (PET) in Engineering Materials: A Review

“…2007; Awwad and Hbeeb [31] have investigated the improvement of asphalt modified with polyethylene (PE). Their studies have been also carried out to determine the best type of PE to be used and its proportion in the asphalt mixture.…”