AASHTO MP 34:18 (2020) Standard Specification for Materials for Sand Seals.
1.1. AASHTO MP 34 specifies quality requirements for aggregate and emulsified asphalt for sand seals on properly prepared bituminous streets.
1.2. A sand seal is an application of emulsified asphalt. followed immediately by an application of a single layer of fine graded cover aggregate, which is then rolled for embedment. The seal may he applied in multiple lifts depending on traffic demands and existing road surface conditions.
2.1. AASHTO Standards:
• M 140, Emulsified Asphalt
• M 208, Cationic Emulsified Asphalt
• T 1 I, Materials Finer Than 75-Mm (No. 2(X)) Sieve in Mineral Aggregates by Washing
• T 27, Sieve Analysis of Fine and Coarse Aggregates
• T 176, Plastic Fines in Graded Aggregates and Soils by Use of the Sand Equivalent Test
3.1. Definitions:
3.1.1. rapid-setting type emulsified asphalt—any emulsified asphalt containing the CRS. CHFRS, HFRS, or RS designation as referenced in M 140 or M 208.
3.1 .2. medium-scuing tipe emulsified asphalt—any emulsified asphalt containing the MS or HFMS designation as referenced in M 140.
3.1 .3. calionic slow-setting—any emulsified asphalt containing the CSS-l or CSS- I h designation as reference in M 208.
4.1. This standard specification may be used to select and evaluate materials for the construction of emulsified asphalt sand seals.
Emulsified asphalt for sand seals shall meet the requirements of rapid-setting, medium-setting, or caliornc slow-setting type emulsified asphalt in M 140 or M 208.
5.2. The emulsified asphalt residue hardness classification is determined by the Owner Agency utilizing regional climatic and traffic conditions.
Sand seal aggregate shall consist of tine granular material, composed of hard, durable particles, uniform in quality, and free from deleterious materials. Gradations and quality requirements are specified in Table I. All percentages are by mass. The aggregate type to be used will be as specified by the Owner Agency.AASHTO MP 34 pdf download.