Performance of Warm Mix Asphalt containing Sasobit®: State-of-the-art

Fatigue behavior of rubberized asphalt concrete mixtures containing warm asphalt additives

This synthesis documents the results of a comprehensive review of worldwide information dealing with the following issues as related to warm-mix asphalt (WMA) technology: (1) current state of the art/practice of WMA, (2) benefits and costs of WMA technology, (3) plant modifications to accommodate certain WMA processes, (4) mixture design and analysis, (5) pavement structural design, (6) durability and performance, (7) performance-related testing, (8) quality control, (9) specifications, and (10) construction guidelines. A summary of findings and recommendations is provided. Also included in this synthesis is a complete documentation of the first warm-mix asphalt field trial conducted by the Texas Department of Transportation.

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A Synthesis of Warm-Mix Asphalt

Warm Mix Asphalt (WMA) technology, recently developed in Europe, is gaining strong interest in the United States. By lowering the viscosity of asphalt binder and/or increasing the workability of mixture using minimal heat, WMA technology allows the mixing, transporting, and paving process at significantly lower temperature. Using this new technology, asphalt mix can be produced as much as 100oF lower than traditional hot mix asphalt (HMA). Several benefits of lower mixing and compaction temperature include: less emission, savings in energy cost, longer construction season, less odor, and construction during non-peak periods. Despite the apparent benefits, some researchers are concerned about the long-term performance of this new mixture. In the last few years, dozens of field test sections have been constructed throughout the USA using different WMA technologies. It is too early to report the performance; but so far, no negative performance has been reported in the literature. In the last few years, several large national and state level research projects have been initiated to evaluate, validate, and implement this new technology. This report documents the results of a comprehensive review of worldwide information dealing with the following issues as related to WMA: Current state of the art/practice of WMA; cost and benefits of WMA technology; plant modifications to accommodate WMA; mixture design; durability and performance; performance related testing; quality control; specifications; and construction guidelines.

https://rosap.ntl.bts.gov/view/dot/16887/dot_16887_DS1.pdf

A Review of Warm Mix Asphalt

The asphalt industry is constantly attempting to reduce its emissions as concerns are growing on global warming. This is done by decreasing the mixing and compaction temperatures of asphalt mixtures without affecting the properties of the mix which is possible through numerous available technologies in the industry. The production of asphalt mix is done by warm mix asphalt (WMA) technology at considerably lower temperatures (120°C or lower). Less energy consumption, lower mixing and compaction temperatures, early site opening, reduced ageing, fewer emissions, cool weather paving, better workability and, finally, an extended paving window could be mentioned as some of the benefits obtained by using the WMA. This paper presents the WMA techniques and technologies such as foaming techniques, wax and chemical additives techniques. Additionally, the performance of WMA popular technologies such as Sasobit®, WAM®-Foam, Evotherm®, Low energy asphalt, Rediset® WMX and REVIX™ are fully described.

/pdf/an-overview-of-the-emerging-warm-mix-asphalt-technology-2e5dfcjjua.pdf

An overview of the emerging warm mix asphalt technology

Warm-mix asphalt (WMA), which reduces the production temperatures (mixing and compaction) while maintaining the advantages of hot-mix asphalt (HMA), is becoming an attractive paving material. In this study, rheological properties of two commonly used performance grade (PG) binders (PG 64-22 and PG 70-28) were evaluated, with and without Sasobit and Aspha-Min additives. For PG 64-22, 2%, 3%, and 4% Sasobit additive reduced the mixing temperature of the pure binder from 163°C to 147°C (i.e., by 16°C). In case of the PG 70-28, the reductions are 10°C, 12°C and 13°C, respectively, for 2%, 3%, and 4% Sasobit additive. No significant decrease in mixing temperature by the Aspha-Min additive was observed in using the rotational viscometer. Evaluation of the binders on the basis of G*/sin(δ) demonstrates no negative effect on high-temperature grading due to high-temperature viscosity reduction. With the addition of 4% Sasobit additive, the high-temperature binder grading of PG 64 (actually PG 65) increases to PG 6...

Marie Louise Therese Anne Guegan

Papers

Comparative Laboratory Study of Sasobit and Aspha-Min Additives in Warm-Mix Asphalt