Shingle recycling advocates point to performance and specification barriers; researchers studying balanced mix design

Dan Horton of ASR Systems told MassDEP stakeholders that asphalt shingle recycling has matured technically but faces performance and specification barriers that limit use in hot mix asphalt in New England.

Horton said most recycled asphalt shingles (RAS) historically have been used in roads (3/8" RAS) and that performance concerns — cracking, binder activation and raveling — explain much of the limited adoption. He pointed to the Federal Highway Administration’s Balanced Mix Design (BMD) approach as a performance‑based alternative to fixed volumetric caps and noted a University of Massachusetts Dartmouth research grant (~$600,000) to study BMD implementation.

Horton and MassDEP staff also reviewed roofing‑manufacturer initiatives to increase diversion — some manufacturers are piloting extraction and pelletization approaches and several firms target diversion goals (Horton said the industry has "aspired to recycle 50%" of waste). MassDEP staff said New England lacks a large end market for RAS in hot‑mix surface layers and flagged gravel/unpaved surfacing or binder layers as nearer‑term opportunities.