Poly Burlap: Ideal for Wet Curing Concrete
By Deb Amorde
Before diving into what poly burlap is and why’s it’s great for wet curing concrete, I want to take a moment and look at curing itself.
Curing serves two main purposes. First, it retains moisture in the slab so concrete continues to gain strength. Second, it delays drying shrinkage until the concrete is strong enough to resist shrinkage cracking.
Once you’ve poured concrete you can choose not to cure it (not a good idea), you can cure it with chemicals (better, but not ideal) or you can wet cure. Wet curing is the gold standard because it supplies much-needed moisture for hydration. Wet curing can be accomplished in several ways - with continuous water spraying known as “fogging,” with chemicals such as waxes or resins, or with coverings like plastic or natural materials such as cotton, straw or burlap.
What is Poly Burlap
Now that we’ve got some context, let’s look at poly burlap. Poly burlap curing blankets are two-ply covers made from a 10 oz. burlap sheet laminated to a 5 mil white coated polyethylene fabric usually coming in 10’x100’ rolls. These blankets are designed for wet curing of poured concrete during warm temperatures.
The burlap side of the blanket faces down towards the concrete because burlap’s natural moisture absorbing fibers hold water and evenly distributes it over the surface. While the white-coated poly fabric faces up reflecting sunlight and intense heat rays. This curing method allows for a smoother, harder and more durable concrete surface and meets AASHTO M-182, Class II, and ASTM C-171 specifications when chemical cures are not allowed.
Other common names for poly burlap are: Burlene, Curlap, Curing Blankets and Concrete Curing Blankets.
Poly Burlap Applications:
• Freshly poured concrete
• Interstates & highway projects
• Bridge & overpass projects
• Decks, slabs, concrete surfaces
• Retaining walls & concrete columns
• Vertical concrete construction
• Burlap is a moisture absorbent material
• White coated poly reflects sunlight and intense heat rays
• Material is flexible
• Easy handle, easy to move
• Meets DOT requirements for concrete curing