New Ways to Cure Pervious

Curing pervious concrete is no doubt one of the most critical aspects of a successful placement. Historically, the curing has been done with plastic sheeting covering the pavement for 7-10 days. For lack of a better alternative, this method is the standard even though it comes with many disadvantages. One of the main downside to using plastic sheeting is the amount of plastic that goes into landfills. For every SF of pervious concrete cured this way, 1.2 SF of plastic will be used. Yes, recycling is an option but we have to admit that hardly no one (if anyone) recycles their plastic. Every once in a while, if the plastic is not damaged, it will be reused but eventually it gets thrown away.

Then we consider the placement restrictions that plastic sheeting puts on the installer. Use of the plastic forces the installer to pour in strips and produces all those construction joints, by far the hardest joints to keep from raveling. Some feel these joints have poor compaction and some feel they have insufficient curing, but whatever the cause, I say minimize the joint and you'll have less problems. And of course we need to consider the labor costs and impact that plastic curing has on the project schedule. At least one week after placement, someone has to remove the plastic, and this phase of the project is stalled for the curing week. Although no traffic should be allowed on the pavement, sawing and/or stripping could take place during the curing phase if not for the plastic sheeting. Again, many disadvantages.

Thankfully, there are other ways to cure pervious that I expect will soon be available if not already. Here are some that I am aware of:

One manufacturer is developing a biodegradable plastic curing sheet for pervious concrete. One manufacturer has developed a sprayed on curing compound combined with a densifier for improved surface durability. Many are aware of the internal curing admixture that I have been using for years but also saturated lightweight sand is being used in pervious concrete for internal curing (expect ACI report on internal curing soon).

Using these curing techniques individually or combined should prove to be an advantage to pervious concrete, providing the benefits of curing without the disadvantages of traditional plastic sheeting.