Green Building Kimberly Johnston, Associate Editor
Pervious Concrete: How to
Properly Place and Cure
A successful concrete
pour starts with
proper placing and
curing — the same
can be said for
pervious concrete pour is a
three-step process — placing
to elevation, compaction and
curing. Unlike traditional concrete
which looks for a smooth, ﬁnished
surface, pervious concrete contrac-
tors strive for compaction, aggregate
interlock and a porous surface.
The pour A pervious concrete pavement placement works like an assembly line, says Dale
Like traditional concrete, there are many Fisher, with crew members working the ready-mixed truck’s chute, members
working the screed, and others following with finishing tools.
different methods and equipment for
pouring pervious concrete. However,
since pervious concrete is a low-slump need a deﬁnite straight edge, such as provide the same consistency of com-
mixture, it cannot be pumped into trail pathways. paction that screeds can, Fisher says.
place like traditional concrete. The most Fisher likens a pervious pour to that Contractors also need to avoid over-com-
common methods of placement are of a long assembly line with the only paction when using plate compactors.
directly from a ready-mixed truck, with a difference being the crew members The screed is followed by the ﬁnish-
concrete buggy or by conveyor. are working much closer together ing crew, which has multiple jobs.
Pervious concrete is commonly during a pervious pour. “Everything After screeding the pervious, it needs
poured in formed-out strips, says Dale happens at the same time with pervi- to be cross rolled. Typically, one crew
Fisher, CEO of PCI Systems, LLC. ous concrete. With regular concrete member follows behind the screed
Strips are poured every other to allow ”
it’s spread out, Fisher says. “With with a cross roller, rolling in a perpen-
the pervious the proper amount of traditional concrete the whole slab is dicular direction to the screed. Cross
curing time. Current documents spec- placed before the ﬁnishing operation rolling gives the ﬁnish a nice continu-
ify contractors pour strips between even begins. With pervious concrete ity, Fisher says.
12 and 20 feet wide. However, this your placement, ﬁnishing and curing is Joints are also placed during this
can be a challenge when pouring very all done at the same time. ” stage. Fisher says they are placed just
large areas that have tight scheduling Typically, there is one crew member like traditional concrete joints by either
deadlines. New equipment, such as near the ready-mixed truck’s chute (or using a roller jointer while the pervious
laser screeds, allows contractors to by the buggy or conveyor) directing the is still wet or sawing the joints after it
pour larger areas without strips for pervious concrete where it should go. has cured.
situations like these. The screed operators are the next in The ﬁnal ﬁnishing crew members
Some pervious concrete can be line, screeding the pervious concrete follow with hand ﬂoats to touch up the
placed with a concrete slipform paver. to the proper elevation and compacting edges. “Don’t use