PC Products 72561 PC-Concrete Two-Part Epoxy Adhesive Paste for Anchoring and Crack Repair, 8.6 oz Cartridge, Gray

Why it's worth it

A two-part epoxy paste that mixes at the nozzle and cures harder than the concrete around it. It's the right call for spalled edges and crumbling steps that carry weight, and the wrong call for any crack that opens and closes with the seasons.

This isn't really a crack sealant. It's a structural adhesive that happens to fill cracks. PC Products rates it for anchoring threaded rod and bolts into concrete, which tells you everything about the bond strength — owners have used it to set rebar and to reattach broken chunks of concrete steps and ornaments. If your driveway has a spalled edge crumbling under tire load, this is what puts it back together.

The dual cartridge mixes at the nozzle, so you're not eyeballing a ratio in a cup. Work time is about 20 minutes at room temperature and it's cured in roughly four hours, which is fast. It's also high-tack and moisture-resistant, so you can use it in a crack you couldn't get bone-dry — helpful on a shaded driveway or in a humid week.

From our review of 8 concrete crack repair kits for driveways, by David Sinclair, Managing Editor

What we like

• +This isn't really a crack sealant
• +The dual cartridge mixes at the nozzle, so you're not eyeballing a ratio in a cup
• +The temperature range is the widest here

What to know

• –It cures completely rigid, and that's a genuine limitation
• –Getting it out of the tube is work
• –It's runnier than you'd expect for a paste