Hot Mix Asphalt Paving

The typical cold paving method includes mixing aggregates with asphalt emulsion and thus it does not involve heating the components used to produce the asphalt-based formulation. Asphalt emulsions will be discussed in Sect. 12.3. 

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Dewatered pond fines have the potential for use as a mineral filler in hot mix asphalt paving, depending on the clay content of the pond fines... 

The modified binder is commonly referred to as asphalt-rubber Asphalt-rubber binders are used primarily in hot mix asphalt paving, but are also used in seal coat applications as a stress absorbing membrane (SAM), a stress absorbing membrane interlayer (SAMI), or as a membrane sealant without any aggregate... 

Hot Mix Asphalt Paving Handbook (2000) (2nd ed.). Covers paving, plant operations, materials transportation, surface preparation, and quality control. 

The Shell papents broadly cover a bituminous paving composition in which the aggregate is coated with bituminous binder and the excess undissolved sulfur acts as a filler in the void spaces between the aggregate. The process is particularly adaptable for use with inexpensive, ungraded sands which are not suitable for use as an aggregate in a conventional hot mix asphalt concrete this mix class has often been called sulfur-asphalt-sand (SAS), but Shell s product is currently tradenamed THERMOPAVE. 

Cold mix asphalt (central processing facility) - The RAP processing reqnirements for cold mix recycling are similar to those for recycled hot mix, except that the graded RAP product is incorporated into cold mix asphalt paving mixtnres as an aggregate substitute ... 

Anderson DA (1987) Guidelines for the use of dust in hot mix asphalt concrete mixtures. Proc Assoc of Asphalt Paving Technologists 56 492-516... 

Vansteenkiste S. and A. Vanelstraete. 2008. Properties of fillers Relationship with laboratory performance in hot mix asphalt./o r a/ of the Association of Asphalt Paving Technologists, Vol. 77, pp. 361-394. Philadelphia, PA Association of Asphalt Paving Technologists. 

Bari J. and M.W. Witczak. 2006. Development of a new revised version of the Witczak E predictive model for hot mix asphalt rmxtme s. Journal of the Association of Asphalt Paving Technologists from the Proceedings of the Technical Sessions, Vol. 75, pp. 381-423. Savannah, GA. 

Figure 8.1 Typical layout of batch plant for hot mix asphalt. (From EAPA and NAPA, The Asphalt Paving Industry A Global Prospective, 2nd Edition, GL 101. Brussels EAPA, 2011 Courtesy of National Asphalt Pavement Association, http //www.asphaltpavement.org.)...

Gallivan V.L., G.K. Chang, and D.R. Horan. 2011a. Practical implementation of intelligent compaction technology in hot mix asphalt pavements, journal of the Association of Asphalt Paving Technologists, Vol. 80, p. 1. 

The recommended material for paving highways in the United States is Superpave hot-mix asphalt. Superpave was developed in 1987-93 during a US 50 milhon research project sponsored by the Federal Highway Administration. 

If straight-mn asphalts are reduced to a hardness below 300 penetration (30 mm), they are termed asphalt cements. For hot-mix paving, either the AC-10 viscosity grade or the next harder AC-20 grade is commonly specified. 

Construction Procedure. Paving with a sulfur—asphalt hot mix is exactly the same as with asphalt. Conventional dump trucks are used to haul the hot mix from the asphalt plant to the road. There the mix is spread with standard pavement equipment and compacted with conventional rollers. Measurements on the completed pavements verify that sulfur asphalt mixes have good workability and are virtually indistinguishable from conventional asphalt. 

Hydrogen sulfide emissions were monitored at the sulfur-asphalt mixing equipment at the hot-mix plant and at the paving site. A Houston-Atlas ambient H2S detection system, furnished and operated by the U.S. Bureau of Mines, was used as well as portable equipment such as a Rotorod Gas Sampler and Drager tubes. The emissions at some of the critical areas of the hot-mix plant and paving site are given in Table VI. 

The studies illustrate that the two sulfur-asphalt systems are complementary. The primary objective for using the sulfur-extended binder system is to use sulfur as a diluent to conserve asphalt used in conventional hot mixes. No asphalt saving is realized using Thermopave. The unique features of this process are that it permits the manufacture of high-quality paving materials using inexpensive, poorly graded sands and yields pourable mixes, similar to cement concrete. 

The asphalt paving industry in North America involves an annual expenditure of about 60 billion dollars (U.S.). Hie average cost of the asphalt binder in a typical hot-mix paving contract in Ontario is about... 

The process developed by SNPA involves a dispersion of sulfur in asphalt to form a sulfur/asphalt (S/A) binder. This S/A binder is then used to produce hot-mix paving mixtures with conventional mix-plant and paving equipment. 

Sources Adapted from ASTM D 3515, Standard specification for hot-mixed, hot-laid bituminous paving mixtures, West Conshohocken, Pennsylvania, US ASTM International, 2010 and Asphalt Institute, Superpave mix design, Superpave Series No. 2 (SP-2), 3rd Edition, Lexington, USA Asphalt Institute, 2001. 

Almost 90 % of US paving asphalt consumption is for hot mix. The remaining 10 % of the paving asphalt usage (approximately 7 % of the total asphalt consumption) is comprised of asphalt emulsions, primarily used for preventive maintenance and rehabilitation techniques such as chip seal, slurry seal and microsurfacing. Emulsified asphalts are also used for construction in recycling of old paving materials. 

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