AASHTO PP94:18(2020) Standard Specification for Determination of Optimum Asphalt Content of Cold Recycled Mixture with Foamed Asphalt.
Note 1—Take cores using a pattern that results in a representative sample of the pavement to be recycled, including at or near lane lines, within and between wheel paths. at the pavement edge, and within shoulders if shoulders are to be recycled. Provide at least 180 kg (400 lb) of RAP per design, or more if asphalt content or binder properties or recovered aggregate gradation analysis of the RAP are desired.
6.1.2. Crush cores at ambient temperature or colder to obtain materials for the mix design.
Note 2—A jaw crusher, laboratory milling machine, or other suitable method is recommended for modeling the particle shape and gradation expected during recycling.
6.1.3. As an alternative to obtaining and crushing cores, oNain RAP by milling. Mill the pavement from areas to be recycled to the specified depth.
Note 3—Consider using a cold planer (milling machine) to obtain a RAP sample if the pavement section is uniform and a representative section can be milled. If the existing pavement changes within the limits of the project, obtain separate samples for each area and prepare separate mix designs for each sample.
6.2. Sampling Existing StocApiles for CCPR:
6.2.1. Remove the crust of the stockpile in accordance with R 97 and then sample the RAP in accordance with R 90.
6.2.2. Obtain at least 180 kg (400 Ib) of RAP per design. and obtain at least 14 kg (30 Ib) more if asphalt content, recovered binder properties, or aggregate properties of the RAP are desired.
6.3. Processing of Recycled Asphalt Pa vein ciii (RAP) Materials:
6.3.1. Conduct a sieve analysis in accordance with T 27 on a representative sample of the RAP, with the exception that drying the RAP to a constant mass shall be performed at 40 ± 2°C (104 ± 4°F). If a significant amount of fine uncoated particles are present. perform a washed sieve analysis Of a representative sample in accordance with T 11.
6.3.2. Process RAP materials to model the gradation expected during recycling. The produced RAP gradation shall fall within the gradation band suggested in MP 38.
6.3.3. Obtain two representative samples of processed RAP for T 164 or T 308 testing for Section 7.
7. DETERMINATION OF ASPHALT CONTENT AND GRADATION OF EXTRACTED AGGREGATE FROM RAP
7.1. Perform T 164 or T 308 on two representative samples set aside from Section 6.3.3.AASHTO PP94 pdf download.