Hot mix asphalt

Asphalt concrete is primarily used as a structural pavement surface constructed over a subgrade and a subbase. It is designed to support the traffic load and distribute the load over the roadbed. Asphalt concrete pavements can be constructed using hot mix or cold mix asphalt. Hot mix asphalt is a mixture of tine and coarse aggregate with asphalt cement binder that is mixed, placed, and compacted in a heated condition. Cold mix asphalt is a mixture of emulsified asphalt and aggregate, produced, placed, and compacted at ambient air temperature. Cold mix asphalt pavement usually requires an overlay of hot mix asphalt or surface treatment to resist traffic action. 

JEGEL, Steel Slag Aggregates Use in Hot Mix Asphalt Concrete, final report for the Steelmaking Slag Technical Committee, April, 1993. 

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. 

Standards of Performance for Large Municipal Waste Combustors for Which Construction is Commenced after September 20, 1994 or for which Modification of Reconstruction is Commenced after June 19, 1996 Standards of Performance for Hospital/Medical/Infectious Waste Incinerators for which Construction Is Commenced after June 20, 1996 Standards of Performance for Portland Cement Plants Standards of Performance for Nitric Acid Plants Standards of Performance for Sulfuric Acid Plants Standards of Performance for Hot Mix Asphalt Facilities Standards of Performance for Petroleum Refineries... 

INVESTIGATION ON DETERIORATION OF RECYCLED HOT-MIXED ASPHALT CONCRETE PAVEMENT AND A TRIAL RERECYCLING OF ASPHALT CONCRETE... 

Keywords Asphalt concrete pavement, durability, pavement recycling, recycled hot-mixed asphalt concrete, re-recycling. 

The use of plant-recycled hot-mixed asphalt (HMA) for public road pavement in Japan first began in 1975. The Japan Road Association promoted the technology for plant-recycled HMA pavement in Japan with its 1984 publication of The Plant-Recycled HMA Pavement Technical Guideline, and since 1985, positive efforts have been made to reuse more reclaimed asphalt pavement (RAP). 

Yoshikane, T., Kondo, K. and Funahasi, H. (1979) Properties of recycled hot-mixed asphalt mixture, Proceeding of 13th Japan road conference. 

Takagi, T., Funahasi, H. and Miyata, T. (1987) Surface properties of recycled hot-mixed asphalt pavement by long-term performance, Proceeding of 17th Japan road conference. 

Kuriyama, M., Yoshikane, T., Kaneda, M. and Ookouchi, T. (1994) Durability and re-recyclability of hot-mixed asphalt pavement, Road Construction. 

Japan Asphalt Mixture Association, Report of research on the actual condition of recycled hot-mixed asphalt mixture, Mixture product annual report. 

Mix Handling Trials. The general objective in conducting field trials was to use, with minimum modification, conventional asphalt equipment for processing, transporting, and placing sand-asphalt-sulfur mixes. To date, the mixes have been processed in batch-type hot-mix asphalt plants. Details of the processing steps were published in a previous report (4). In 1975, we intend to evaluate a continuous-type hot-mix... 

Construction and building (building materials and trade). The use of quicklime and hydrated lime in soil treatment for the construction of road foundations and large areas, such as airfields, car parks, etc, is well established in the USA and France and is growing elsewhere. Lime products have been used for many thousands of years to produce mortars which have stood the test of time. Mortar for masonry, render and plaster remains an important outlet for lime. Other outlets include the production of various calcium silicate products, aircrete, and limewash, and the use as an additive for hot-mix asphalt. 

A growing use for hydrated lime, particularly in the United States, is as an additive to hot mix asphalt [26.21, 26.22]. The main benefit is that it increases the resistance of the asphalt to water stripping. Lime also acts as a mineral filler and as an antioxidant. 

Antioxidant. Preliminary results (1994) from laboratory and field tests have indicated that the addition of hydrated lime also reduces the oxidation of the binder, which causes hardening and stiffening leading to premature failure of hot mix asphalts. The favoured method of addition of the hydrated lime is as a powder to a moist aggregate (containing 2 to 3 units of percent above the saturated surface-dried moisture content of the aggregate). 

Lime specifications. Only slaked lime should be used in hot-mix asphalt. Both powdered hydrated lime and milk of lime meeting the requirements of Types CL 70, 80, or 90 [26.18] would be fully satisfactory, as would Type S dolomitic limes [26.19]. 

J.A. Epps, Lime in Hot Mix Asphalt Design, Properties and Performance , Proc. of the International Lime Conference, Berlin, 1994. 

Crumb rubber used in hot mix asphalt normally has 100% of the particles finer than 4.75 mm. Although the majority of the particles used in the wet process are sized within the 0.42-1.2 to mm range, some crumb rubber particles maybe as fine as 0.075 mm. The specific gravity of crumb rubber is approximately 1.15, and the product must be free of fabric, wire, or other contaminants. 

Asphalt concrete Aggregate - Hot mix asphalt - Cold mix asphalt - Seal coat or surface treatment Asphalt cement modifier Mineral filler... 

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