AASHTO MP 43-20 PDF Download

The AASHTO MP 43-20 standard outlines the requirements for the materials used in the application of scrub seals. A scrub seal is a treatment that involves the application of emulsified asphalt using a scrub broom, followed by the immediate application of a single layer of cover aggregate. This treatment can be used as a wearing surface or as an interlayer.

The standard focuses on two main materials: aggregate and emulsified asphalt. It specifies the quality requirements for these materials to ensure the effectiveness and longevity of the scrub seal. This includes parameters such as particle size distribution, shape, cleanliness, and durability of the aggregate. Similarly, the emulsified asphalt should meet specific viscosity, residue, and particle charge requirements.

By establishing these specifications, the standard aims to provide guidelines for the selection and use of materials that will result in a high-quality scrub seal application. This helps to ensure the performance and durability of the treatment, contributing to the overall safety and longevity of the road infrastructure.