Concrete mix design follows ACI 211.1 (normal weight) or ACI 211.2 (lightweight). MnDOT requires trial batches with strength verification at 7 and 28 days. Mix design parameters: w/c ratio per durability requirements, minimum cement content per exposure class, air content 4.5-7.5% for freeze-thaw exposure. Maximum aggregate size: 1.5 inches for general use, 3/4 inch for bridge decks. Alkali-silica reactivity (ASR) mitigation per MN ASR policy using SCMs or lithium-based admixtures.
References: AASHTO current edition, MN Standard Specifications, FHWA Technical Advisories, and applicable federal regulations (23 CFR). Contractors shall maintain current copies of all referenced standards on the project site.
Source: MnDOT Materials Testing Manual, 2024 Edition. Pages 9–10 of 25.