AASHTO MP 38-18 pdf free download
AASHTO MP 38-18 pdf free download.Mix Design of Cold Recycled Mixture with Foamed Asphalt.
3. TERMINOLOGY
reclaimed asphalt pavement (RAP)—removed and/or processed pavement materials containing asphalt binder and aggregate.
3.2. cold in-place recycling (€‘IR)—the on-site recycling process in which the existing asphalt pavement is recycled using a specialized train equipment (tanker trucks, cold planing machines, crushing/screening or sizing units, mixers, payers, and compaction rollers). The CIR process uses 100 percent of the on-site generated RAP, and a foamed asphalt with or without a combination of additives (e.g., lime, cement, and aggregate) to produce CIR mixture, and typically treats an asphalt pavement with a depth of 75 to 100 mm (3 to 4 in.). The CIR mixture is used as a base layer overlaid with a surface treatment or asphalt overlay.
3.3. cold central-plant recycling (CCPR)—the process in which the asphalt recycling takes place at a central location using a stationary cold mix plant. The stationary plant could be a specifically designed plant or a CIR train minus the cold planing machine set up in a stationary configuration. The CCPR mixture is used as a base layer overlaid with a surface treatment or asphalt overlay.
SIGNIFICANCE AND USE
4.1. This standard may be used to select and evaluate materials for cold recycling mix designs.
5. RAP REQUIREMENTS
5.1. Process the RAP that is collected from an existing stockpile or crushed from cores to produce two of the three gradation bands shown in Table 1. Alternatively, if experience has demonstrated consistent field gradations from milling, process the RAP to that gradation.
FOAMED ASPHALT AND ADDITIVE REQUIREMENTS
Foaned Asphalt:
6.1 .1. The asphalt binder shall be a performance-graded (PG) binder, meeting the requirements of M 320 or M 332, which is appropriate for the climate and traffic-loading conditions at the site of the paving project or as specified by the contract documents.
6.1.2. For foamed asphalt, use LTPPB1nd 3.1 software to select the low temperature PG requirements from M 320 for the asphalt binder. In the LTPPBind 3.1 software, the nearest weather station is selected for the project. The depth to the top of the cold recycled layer is input as the depth of layer. The desired reliability is established by agency policy. A spread of 89 or less between the high PG and the low PG temperatures is normally acceptable in choosing an asphalt binder. Determine the optimum foaming water content to achieve the desirable workability of foamed asphalt mixtures. Determine the other properties of the foamed asphalt to meet mixture requirements.
Note 3—The selection of desired reliability may be influenced by the initial cost of the materials and the subsequent maintenance costs.
Note 4 The low temperature requirement can be more conservative in temperate climates or for a CIR layer with a thick overlay. For example, if LTPPBind determines a cold temperature minimum of —10°C (14°F) in a temperate climate and the predominant grade for that climate is
—16°C (3°F), then an asphalt binder of—16°C (3°F) or —22°C (—8°F) is acceptable for foaming.
6.2. Other Additives:
6.2.1. If Type I or II cement is used it shall meet the requirements of M 85.
6.2.2. If hydrated lime is used it shall meet the requirements of M 216.AASHTO MP 38-18 pdf download.
