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Characterizing low-temperature field produced asphalt mix performance
Published in A. Kumar, A.T. Papagiannakis, A. Bhasin, D. Little, Advances in Materials and Pavement Performance Prediction II, 2020
Joyce Kamau, Joseph Podolsky, Chris Williams
The current specification for Fracture energy (Gf) measured through Disk-shaped Compact Tension (DCT) (ASTM D7313-07a) test in Iowa is contained in IM510 and pertains to when binder replacement exceeds 30% for mixtures containing only RAP or 25% for mixtures containing recycled asphalt shingles. "The average of two specimens shall meet the minimum fracture energy requirements tested at 10°C warmer than the low climatic temperature (normally specified as the low-temperature performance grade:Very High Traffic (VT) 690 J/m2High Traffic (HT) 460 J/m2Standard Traffic (ST) 400 J/m2"Iowa Material IM510 Method of design of asphalt mixture.
Asphalt Mixtures
Published in M. Rashad Islam, Civil Engineering Materials, 2020
Recycled (or reclaimed) asphalt shingles (RAS) are collected from roof tear-offs, processed, and re-used for pavement. Shingles can contain between 20% and 36% of asphalt, by weight. This asphalt can be used to bind aggregates like the conventional asphalt, or other similar materials. Shingle waste can be collected from two sources. The first source is the manufacturer waste shingles, directly from manufacturers of asphalt shingles. This waste is highly appreciated, as the composition of the material is fairly well known. The other type of waste shingle is known as tear-off from re-roofing or roof removal projects. Literature shows that RAS is beneficial for pavement in terms of increased rutting resistance, reduced cracking, and less compaction effort required (Roque et al. 2018). RAS is also economical and environmentally friendlier, as it saves virgin aggregate, virgin asphalt binder, and reduces landfill demands.
Roofings
Published in Michael McEvoy, External Components, 2014
Properly preserved and installed, shingles have a life expectancy of more than 50 years. There is no British Standard, they are normally specified in the UK to Canadian catagories, the only suitable type, other than for undercoursing, being Canadian Standards Association no. 1 grade. Shingles are cut from the blocks of western red cedar in a tapered cross-section, with edges trimmed square and parallel to uniform length of 405 mm. Widths are random from 100 to 350 mm. Hip and ridge cappings are supplied made from two shingles fastened together at an angle. The natural brown colour of the timber weathers to silver grey after a period of months. Western red cedar is the best insulator of all commonly used softwoods and in themselves, shingles are the most insulative of all weather-coat roofing materials.
Rheological multi-scale evaluation of RAP and RAS binders mobilisation in hot mix asphalt
Published in Road Materials and Pavement Design, 2023
Abdeldjalil Daoudi, Anne Dony, Daniel Perraton, Alan Carter
Both for environmental and economic concerns, the use of recycled material in pavement is more and more important for companies and road owners. Reclaimed Asphalt Pavement (RAP) is now a commonly used material. It consists of about 95%wt of aggregates and 5%wt of bituminous binder aged during its life on the road (mechanical + thermal ageing). Post-consumer Recycled Asphalt Shingles (RAS), initially used as roofing materials, especially in North America, can also be reused for road construction in combination with virgin materials. These RAS can contain 25% to 40%wt of bituminous binder combined with fine aggregates and fibres. At the end of their life cycle, they are recovered and shredded to be combined with new materials in the manufacture of Hot Mix Asphalt (HMA). The combined use of RAP and RAS seems to be a good way to reduce costs and reuse non-renewable natural resources (bitumen and aggregates), while reducing energy and emission associated with the extraction and transportation of the new material. However, it is important to consider the different natures of materials, in particular the recycled bitumen, to understand their influence on the final material to ensure good behaviour under traffic and climatic conditions throughout its service life.
The crossover temperature: significance and application towards engineering balanced recycled binder blends
Published in Road Materials and Pavement Design, 2019
Lorena Garcia Cucalon, Fawaz Kaseer, Edith Arámbula-Mercado, Amy Epps Martin, Nathan Morian, Sara Pournoman, Elie Hajj
The use of reclaimed asphalt pavements (RAP) and recycled asphalt shingles (RAS) in asphalt pavements has become a common practice due to prevailing economic and environmental benefits. RAS can be classified as manufactured waste asphalt shingles (MWAS) or tear-off asphalt shingles (TOAS) depending on their source. Regardless, both types of RAS are heavily oxidised, with TOAS being further aged due to its exposure to the environment in–service. Since recycled binders contained in RAP and RAS materials are extremely oxidised and brittle, the primary concern when employing these materials in asphalt mixtures is susceptibility to cracking.