A pervious concrete pour is also affected by external environmental factors. The ideal environment for a pervious placement is moist, cool and wet, [Dale Fisher] says. "A drizzly day is perfect to pour pervious concrete because you can double your time for pervious placement," Fisher says. A hot and dry environment will make the mix dry quicker, shortening the window of working time. If hot weather is inevitable, Fisher suggests pouring early in the morning or overnight.
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. A 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
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