As sustainability has affected nearly all aspects of our lives, from the cars we drive to the buildings and homes we work and live in, pervious concrete is also gaining respect in the construction industry.
This porous concrete, which allows stormwater to seep into the ground and reduces runoff, is capturing attention. Last year, three-quarters of our readers said they had manufactured pervious concrete.
But pervious concrete has a unique set of challenges for producers and for the contractors who place it. The mixing process is less forgiving than conventional concrete, and close attention must be paid to placing, compaction, and curing. These issues and more will be addressed at Pervious Live, a new event at World of Concrete, Jan. 18-21, in Las Vegas.
Pervious Live will take place in a 10,000-square-foot area of the Gold Lot outside the North Hall of the Las Vegas Convention Center. There will be three demonstration pads for showgoers to walk on. One pad will be placed too dry to demonstrate ravelling and one will be placed too wet to show sealing. The third will be placed as it should be.
Students from the Concrete Industry Management program at Middle Tennessee State University will install the slabs and will be on hand to explain their construction. They also will demonstrate approved ASTM methods on both hardened and fresh pervious concrete. One will be the ASTM C 1701 infiltration test on hardened pervious concrete. The second test is the ASTM C 1688 test on fresh pervious concrete.
Pervious Live will be the industry's only live forum on current pervious concrete technologies. Also in the area, event sponsors will display, discuss, and demonstrate new equipment and test procedures for this rapidly growing material. This event will give attendees the knowledge they need to expand their commercial work.
Also, this exciting event complements training that will be offered 1-4 p.m., Monday, Jan. 17, at the show. Students taking the Classroom Training for Pervious Concrete Certification Program will learn the information necessary to pass the Pervious Concrete Craftsman/ Installer/Technician Certification.
In November, students at Middle Tennessee State University's Concrete Industry Management (CIM) Program in Murfreesboro, Tenn., conducted a test pour of pervious concrete. Perfect pervious concrete was the goal of this test. CIM students from MTSU will install pervious concrete slabs at World of Concrete as part of the Pervious Live demonstration event. For more on the university's CIM program, visit www.mtsucim.com.
Modern Pervious Promoted
The desert near Las Vegas came to life for three days in September when some of the industry's best pervious minds and craftsmen converged for the first Pervmasters Ball.
The event, organized by Bunyan Industries, was the largest gathering of pervious craftsmen ever. Experts from all over the nation, Canada, and Mexico compared notes and demonstrated established and cutting-edge installation and testing methods. “A new collection process for fresh plastic samples is worth to looking into at ASTM,” said Walter Flood IV of Flood Testing Laboratories.
The unique teaching and idea-exchange focused on newly developed testing and sample collection practices unique to pervious mixtures. Modern pervious is the culmination of an ongoing recognition that lighter and wetter mixes are key to the success of this important impervious surface reduction method. Accordingly, test mixes were designed with a 19.3% void content and various admixture entries were dosed with 400 pounds and 100 pounds of cement and ash respectively.
Multiple 3 x 50 comparative test panels for differentiation of product features were placed with half of the base left dry and intentionally roasted without benefit of the usual curing practices. The other halves were placed on a moistened base and afforded normal precautions. Because the material is subject to extreme dehydration during installation, survival methods were studied.
It was evident to all that pervious concrete reduces such threats because of its higher moisture content, resulting in reduced raveling and improved resistance to freeze-thaw damage.
Because in many applications pervious can benefit from additional specialized hydration aids, curing compounds, and densifiers, some of these products were presented and studied. Different aggregates, placing practices, equipment, and new techniques to reduce the Bunyan Industries cumbersome poly-sheeting curing method were also explored
The event was staged at CalPortland's Sloan, Nev., plant and we appreciate the generous support, progressive approach, and careful attention to quality control. Special thanks to Bill Klawitter and Bill Larson, and the entire CalPortland Nevada QC/ Operations team. Additional key contributors were Brian Lutey of Ozinga Brothers, Jim Miller of C2 Products, and Scott Parson and Lonnie Gray of Staker Parson Companies, a division of Oldcastle.
By David Mitchell, founder of Bunyan Industries. Visitwww.bunyanusa.comand Booth #C4629 at World of Concrete.