What type of concrete mix should I use for a driveway in NB?

For a concrete driveway in New Brunswick, specify air-entrained, 30 MPa (4,350 PSI) ready-mix concrete with a water-to-cement ratio of 0.45 or less and a slump of 4-5 inches. This is not the cheapest concrete option, but it is the right specification for NB's freeze-thaw climate — and it is the difference between a driveway that lasts 30-40 years and one that starts scaling and spalling within a decade.

Air entrainment is the most critical specification for NB driveways. When you order ready-mix, ask specifically for an air-entrained mix with 5-7% air content. This is a non-negotiable requirement for any exterior concrete in New Brunswick. The billions of microscopic air bubbles created by air-entraining admixtures give freezing pore water room to expand, dramatically reducing the internal stress that causes surface scaling. Non-air-entrained concrete exposed to 150+ annual NB freeze-thaw cycles will deteriorate within 3-7 years, regardless of strength.

Why 30 MPa instead of 25 MPa: The additional strength of a 30 MPa mix provides better resistance to the abrasion of NB winter maintenance — sand, salt spray from the road, snowplow contact, and ice melt chemicals all work on the surface of your driveway. A denser, stronger concrete resists surface wear significantly better. The cost difference is $15-$30 per cubic yard — about $100-$200 more for a typical driveway, fully worth the durability gain.

Water-to-cement ratio matters more than many homeowners realize. A low water-to-cement ratio (0.45 or less) produces denser, less permeable concrete. When a driver arrives with your ready-mix and the concrete looks stiff, the temptation is to add water to make it more workable. Resist this completely — adding water dilutes the cement paste, increases porosity, and reduces strength. Every extra gallon of water per cubic yard reduces compressive strength by 200-300 PSI. If workability is an issue, your contractor can request a mid-range water reducer (plasticizer) from the ready-mix plant at ordering — this maintains workability at a low water-to-cement ratio.

Fibre reinforcement is a useful addition but not a replacement for wire mesh or rebar. Synthetic polypropylene fibres added to the mix ($15-$25 per cubic yard extra) reduce plastic shrinkage cracking during the finishing stage and add crack resistance throughout the slab life. Many NB contractors specify fibres as standard on driveway pours.

For a typical NB driveway, expect to pay $190-$250 per cubic yard for the proper air-entrained 30 MPa mix delivered. Your contractor should be ordering this specification automatically — if they are not, ask specifically.