100% recycled hot mix asphalt lab samples were modified with five generic and one proprietary rejuvenators at 12% dose and tested for binder and mixture properties. Waste Vegetable Oil, Waste Vegetable Grease, Organic Oil, Distilled Tall Oil, and Aromatic Extract reduced the Superpave performance grade (PG) from 94–12 of extracted binder to PG 64-22 while waste engine oil required higher dose. All products ensured excellent rutting resistance while providing longer fatigue life when compared to virgin mixtures and most lowered critical cracking temperature. Rejuvenated samples required more compaction energy compared to virgin and some oils reduced moisture resistance slightly.

Influence of Six Rejuvenators on the Performance Properties of Reclaimed Asphalt Pavement (RAP) Binder and 100% Recycled Asphalt Mixtures

A state-of-the-art review of parameters influencing measurement and modeling of skid resistance of asphalt pavements

Expansive soils are problematic due to the performances of their clay mineral constituent, which makes them exhibit the shrink-swell characteristics. The shrink-swell behaviours make expansive soils inappropriate for direct engineering application in their natural form. In an attempt to make them more feasible for construction purposes, numerous materials and techniques have been used to stabilise the soil. In this study, the additives and techniques applied for stabilising expansive soils will be focused on, with respect to their efficiency in improving the engineering properties of the soils. Then we discussed the microstructural interaction, chemical process, economic implication, nanotechnology application, as well as waste reuse and sustainability. Some issues regarding the effective application of the emerging trends in expansive soil stabilisation were presented with three categories, namely geoenvironmental, standardisation and optimisation issues. Techniques like predictive modelling and exploring methods such as reliability-based design optimisation, response surface methodology, dimensional analysis, and artificial intelligence technology were also proposed in order to ensure that expansive soil stabilisation is efficient.

Emerging trends in expansive soil stabilisation: A review

Repurposing waste plastics into cleaner asphalt pavement materials: A critical literature review

It has been recognised with growing concern that agricultural and industrial wastes are increasingly produced in large volume. In order to reduce environmental hazards and conserve natural resources, the use of waste materials in highway pavements would be extremely effective in terms of recycling waste materials. The main purpose of this study was to investigate the effects of waste materials as filler on the performance of hot mix asphalt (HMA) mixtures. HMA mixtures containing waste glass powder (WGP), waste brick powder (WBP), rice husk ash (RHA) and stone dust (control mixture) were fabricated and the optimum asphalt binder content was determined for each mixture. The properties of HMA mixtures were investigated by Marshall, indirect tensile stiffness modulus and indirect tensile fatigue tests. The results indicated that WGP and WBP mixtures exhibited higher fatigue life and better performance than other mixtures. In addition, it was determined that there was no considerable difference in the perform...

Laboratory investigation of hot mix asphalt containing waste materials

Effect of rejuvenating agents on stone matrix asphalt mixtures incorporating RAP

Stone Matrix Asphalt (SMA) is a gap-graded bituminous mixture characterised with its improved rut resistance and durability. It has comparatively higher proportion of coarse aggregates and binder mastic with bituminous binder and mineral filler. Drain down of mastic content at various stages of construction is a common issue with SMA, and generally, some fibre additives are used to stabilise the mixture or a modified bitumen is used as the binder material. In this study, shredded waste plastics (SWP) are used instead of other stabilising additives, to prepare SMA mixtures with conventional viscosity graded (VG) 30 bitumen. Mixtures were prepared with four different levels of SWP content, and another mixture without any stabilisers was also prepared using polymer-modified bitumen (PMB). Specimens were prepared in superpave gyratory compactor (SGC) for all mixtures at different bitumen contents to determine volumetric and Marshall properties, and optimum bitumen content (OBC) was calculated for each mixture...

Comparison of Stone Matrix Asphalt mixtures with polymer-modified bitumen and shredded waste plastics

Reclaimed Asphalt Pavement (RAP) is a widely used recycled material in pavement construction. Whereas the integration of RAP into asphalt mixtures is a complex subject and need to understand every aspect that entailed in the mix design. The aim of this review paper is to provide comprehensive knowledge about the developments and challenges of the RAP in the asphalt mixtures, along with the mechanisms involved. The blending process and rejuvenator are two key factors that govern RAP content, and this can even surge up to 100% in the asphalt mixtures. The blending between the RAP and the virgin materials is very crucial in the context of performance and durability of RAP mixtures. While rejuvenator is an additive which may act as a catalyst and enhance the aged RAP binder properties. A detailed description of distinct types of the rejuvenators and their performances are discussed in this paper. Several aspects of the RAP mixtures including mix design, constituent materials, performance, RAP with polymer modified asphalt binder, as well as environmental benefits are highlighted. This study gives information to the researchers, engineers, and designers about the RAP technology.

A review on the mechanisms involved in reclaimed asphalt pavement

Subgrade is one of the important layers of any pavement. It must be able to support loads transmitted from pavement structure without excessive deformation under adverse climatic and traffic conditions. In this investigation, laboratory studies were carried out to evaluate the influence of a commercial electrolyte lignin stabilizer (ELS), fly ash (FA) and a combination of both, on black cotton (BC) soil procured from North Karnataka region in India. Basic geotechnical and engineering properties like unconfined compressive strength (UCS), California bearing ratio (CBR), etc. were determined for both untreated and treated soil. Dynamic repeated load test was conducted to examine the fatigue behaviour of the soil. Durability of the soil was checked by wet-dry (WD) and freeze-thaw (FT) cycle tests, and swelling properties by free swell index test. From the studies, it was observed that consistency limits, dry density, UCS and CBR values were improved for treated soil, with curing periods of 1, 7 and 28 days. Weight loss in FT test was less than 14 % for 12 cycles, which ensures that the stabilized soil has become durable. But none of the samples were observed to be withstanding above five cycles in wet-dry test. Soil stabilized with ELS and FA showed better results compared to soil with only ELS. Swelling was reduced to a great extent with 28 days curing period for the former one. From the experimental results, it can be concluded that this chemical can be used as a stabilizer for existing BC soil in site to enhance its subgrade strength.

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Goutham Sarang

Papers

Effect of rejuvenating agents on stone matrix asphalt mixtures incorporating RAP

Comparison of Stone Matrix Asphalt mixtures with polymer-modified bitumen and shredded waste plastics

A review on the mechanisms involved in reclaimed asphalt pavement

Effect of Electrolyte Lignin and Fly Ash in Stabilizing Black Cotton Soil

Evaluation of rejuvenator’s effectiveness on the reclaimed asphalt pavement incorporated stone matrix asphalt mixtures