Evaluation of Warm Mix Asphalt Performance with High RAP Content

Abstract

The pavement industry is currently forced to find alternative ways to produce asphaltic concrete with the dwindling supply of new resources and the spiraling cost of materials. Warm Mix Asphalt (WMA) using reclaimed asphalt pavement (RAP) offers a sustainable solution to the problem by reducing energy requirements for production and the reuse of old pavement materials. The effects of warm mix asphalt additive (Sasobit) on mixes containing different percentages of RAP were investigated in the laboratory. Three different concentrations of RAP (30%, 40% and 50%) with 1.5% Sasobit by weight of binder were added, and Marshall method was used to produce all samples investigated. Two different mixing and compaction temperatures were used, 155°C and 135°C for mixing and 135°C and 120°C for compaction. The performance of the mixes in terms of stiffness and moisture damage were investigated by carrying out the Indirect Tensile Resilient Modulus Test (ASTM D4123) and moisture susceptibility test (ASTM D 4867). The results obtained showed that there were no substantial differences in volumetric properties, stability and stiffness values of reclaimed mixes than the control mix (conventional hot mix asphalt). In addition, all the mixes investigated achieved the required minimum TSR of 80%. Measured rut depth using the Asphalt Pavement Analyser (APA) device and fatigue cycles to failure using beam specimen indicated that the mixes performed similar to or better than the control mix. The results showed that warm mix asphalt using sasobit-additive and containing high percentages of RAP could be a sustainable alternative to the conventional HMA mix.

Green Road Construction Using Reclaimed Asphalt Pavement with Warm Mix Additive

“…As shown, the resultant graphs exhibit similar trends with the ITS results whereby the resilient modulus increases with the addition of RAP. This finding is in agreement with the study conducted by Arshad et al on the RAP-WMA mixtures containing 30, 40 and 50% with Sasobit [25]. The addition of RAP produces a stiffer mixture due to aged binder and aggregate.…”

Asphalt Concrete Mixture Produced Using Reclaimed Asphalt Pavement and Fly Ash as Artificial Aggregate and Filler

“…This fly ash can be used directly as the filler. The specific gravity of fly ash was 2.24 g/cm 3 , which is similar to that (2.26 g/cm 3 ) reported in other studies [44]. The fly ash contains particles of an extremely fine size that fill the small gaps in the mixture, thereby increasing the density, stability, and impermeability.…”

“…In all the four mixtures, the density increased with the addition of asphalt and RAP. However, the addition of artificial aggregate decreases the density because the specific gravity of artificial aggregate (2.44 g/cm 3 ) is lower than that of RAP aggregate (2.6 g/cm 3 ). Generally, the specific gravity of artificial aggregate is in the range of 1.33-2.35 g/cm 3 [35], [52].…”

“…The utilization of RAP offers economic benefits and preserves natural resources [2]. The usage of high content of RAP can decrease the energy required to produce the asphalt concrete and conserve the aggregates and asphalt resources [3]. Therefore, RAP could be one of the best approaches to enhance sustainable construction.…”

Laboratory comparative assessment of warm and hot mixes Asphalt containing reclaimed Asphalt pavement

“…In addition, all the mixes investigated achieved the required minimum TSR of 80%. The results showed that WMA using Sasobit-additive and containing high percentages of RAP could be a sustainable alternative to the conventional HMA mix [13]. Another researcher assessed the moisture sensitivity of WMA containing high RAP content by TSR and MR tests.…”