Fiber Reinforced Pervious Concrete
May 15, 2014
Recently, the National Ready Mixed Concrete Association’s (NRMCA) Concrete INFOCUS publication discussed some opportunities and challenges in its NRMCA Services and Tools article about increased cooperation between concrete producers and contractors.
According to NRMCA, each year parking lots and local roads present a paving market of more than 400 million cubic yards of concrete – a market of which 90%-plus goes to hot mixed asphalt! The article extrapolates that the overall paving market captured by concrete could be increased by 25% in the next 10 years if the market share can be increased just 2% per year.
Replace HMA with pervious concrete in parking lots and local low-trafficked roads and alleys, but not just pervious concrete – fiber reinforced pervious concrete to ensure durability.
STOP Paving with HMA …
Once the question of which provides the best bang for the buck when it comes to paving roadways and parking lots — Portland cement concrete (PCC) or hot mixed asphalt (HMA) — couldn’t be answered so definitively. A clear-cut technical answer was hard to find, and all of the arguments seemed clouded with politically influenced (HMA) answers.
START Paving with Pervious Concrete …
Now a new contender (and tipping point) has entered the competition. PCC now comes in a Swiss cheese version called pervious concrete. Pervious concrete is a concrete designed with a large number of voids built in. The theory is to provide a means of retaining all stormwater on the site versus the water exiting the site and entering gutters and storm sewers as runoff. This concept, which has a growing number of converts, provides a positive way of affecting the environment both on a micro and macro scale.
ACI Supports Pervious Concrete …
American Concrete Institute (ACI) saw the value in pervious concrete technology a number of years ago and established a committee, ACI 522. The committee has developed a general specification as well as other documents that provide the information needed to understand the technology and the appropriate applications. ACI 522 has also participated in the development of this technology through full-scale field projects.
Pervious Concrete Delivers Proven Performance AND Marketing Value …
With pervious concrete, the ready mix professional can provide engineers and owners with a very positive option to HMA for parking lots and low ADT (average daily traffic) roadways that will appeal to the local government agencies. In addition to concrete’s natural superiority over HMA (longer life cycle/fewer repairs; reduced heat absorption and retention), fiber-reinforced pervious concrete is a material that meets all of the environmental requirements of the current codes and is a better answer to the Building Green issue than HMA.
Why Fibers Increase Durability …
To address any questions about the pervious pavement’s stability or resistance to crush or crumble under load due to its void system, add fibers to increase the stability of the pervious pavement cross-section. A maximum quantity of voids is created based on the overall mix design. This is where the use of monofilament polypropylene fibers to stabilize the cross-section comes into play.
We have provided a specification that introduces monofilament polypropylene as the three-dimensional reinforcement system for pervious concrete. Monofilament polypropylene fibers provide reinforcement without blinding the void pattern of the concrete. The dosage level is also a factor, which is addressed in the accompanying Fiber Reinforced Pervious Concrete Pavement specification document.
Help Your Contractors/Engineers Specify Fiber-Reinforced Pervious Concrete …
ABC Polymer’s Fiber Reinforced Pervious Concrete Pavement specification is developed to aid ready mix professionals in presenting pervious concrete to contractors as a Value Engineering alternative to HMA. If you need additional information or have questions about how to present the specification, simply contact Bobby Zellers, PE/PLS, Director, Engineering Services, at RZellers@ABCFibers.com.