Pervious Pursuits

Pervious concrete pavement practitioners were anything but idle this summer. While others vacationed, Duluth, Minn.-based Arrowhead Concrete Works as

Pervious concrete pavement practitioners were anything but idle this summer. While others vacationed, Duluth, Minn.-based Arrowhead Concrete Works as well as Ohio players Mack Concrete and Consumers Builders Supply Co. completed pervious pavement installations for Duluth’s Hope United Methodist Church and Cleveland’s Hydra Park, respectively.

TAMING THE HYDRA

The success in mid-August of Cleveland’s Burning River Fest, highlighting the need for environmental awareness by commemorating the Cuyahoga River fire of 1969, was due in great measure to a water feature designated the Pervious Concrete Hydra Park. The event’s organizer, Great Lakes Brewing Co., contacted Bob Banka, director-Northeast Ohio, Ohio Ready Mixed Concrete Association, after hearing of his pervious concrete presentation to a group of engineers. In the course of touring the site and discussing what Great Lakes Brewing intended for the occasion, Banka hit upon the idea of building a water park incorporating pervious concrete to provide patrons a place to cool down on a hot August day.

Enthusiasm for the idea prompted Banka to propose the project to ORMCA membership at their June quarterly meeting. Approval was obtained, and members were surveyed to determine who was on board to contribute Û fiscally and physically Û to installation of the Pervious Concrete Hydra Park. Thirteen companies volunteered, including BASF, Lafarge, St. Marys Cement, Axim, Essroc, Euclid, Mack Concrete, Consumers Builders Supply, Chas. E. Phipps, contractors Lakota Concrete, R.J. Platten, Donley, and Great Lakes Construction Co., as well as the Great Lakes Cement Promotion Association.

The project comprises a 155- _ 16-ft. slab of colored pervious concrete incorporating #9 stone and four water jets installed in the pavement. The slab was placed over an 18-in. recharge bed laid on nonwoven geo-textile fabric. Additionally, an 8-in. perforated pipe was installed down the center of the recharge bed to capture seepage for pumping into a 500-gal. admixture tank to showcase harvesting of water for irrigation purposes. Further highlighting the capabilities of pervious pavement, three concrete blocks were set into one end of the slab, and two 4- _ 5-ft. sections of both conventional pervious concrete containing ?-in. limestone and a colored pervious mix with #9 stone were poured between the block ridges to field the onslaught of two sprinklers.

ARROWHEAD HITS THE MARK

Proximity to Tischer Creek as well as stormwater runoff restrictions necessitated a porous surface for the 50-space parking lot of Duluth’s Hope United Methodist Church. Among bids submitted by both permeable paver and pervious concrete suppliers, the bid for pervious pavement came in well below that of the competition.

For the parking lot renovation, Arrowhead Concrete Works supplied 205 yd. of pervious mix to create a 7-in.-thick pavement covering just under 10,000 sq. ft. Delivery and placement of 5-yd. loads allowed contractor K. Johnson Concrete and Masonry of Sauk Rapids, Minn., adequate time to place, screed and cover each section.

To facilitate drainage, 17 inches of 1-in.-minus crushed rock were installed prior to placement of the pervious concrete layer. Moreover, the pervious mix design incorporated a partially crushed, ?-in.-minus, glacial-deposit aggregate, enabling a smooth finish with sufficient porosity. Further optimizing mix suitability for the project were Lafarge North America cement, Enduracon Technologies’ fly ash, and Sika admixtures. Concrete placement was started on July 28 and completed July 31.

Arrowhead Concrete’s Ben Carlson notes, It’s always a challenge to produce a new product, and this was no exception. Fortunately, we were able to design a workable mix, and our drivers were quick to learn the ins and outs of hauling pervious concrete. Of the 40 loads that were hauled to this job, we didn’t have one wet load.

FOUNDATION RELEASES UPDATED PERVIOUS CONCRETE RESEARCH

The RMC Research & Education Foundation announces the release of a revised version of its Pervious Concrete Research Compilation. The latest edition includes information on pervious concrete research studies completed and underway since the original compilation was published in June 2006. It also includes abstracts of study findings, as well as links to study information on the internet where applicable. The compilation was updated by the original author, Dr. Heather J. Brown, in conjunction with the Concrete Industry Management Program at Middle Tennessee State University.

Originally, the foundation’s board of trustees commissioned the compilation to better understand the wide range of pervious concrete research already in existence and to ensure funding would not be approved for duplicative research. Given the important role of pervious concrete in the sustainable development movement and the foundation’s desire to fund projects that will improve the application, the trustees sought to have this compilation completed and later updated to obtain a better understanding of the breadth of existing knowledge on pervious concrete, notes RMC Research & Education Foundation Chairman George Gregory of Essroc Cement. Moreover, he adds, Commissioning this study gave us the opportunity to again partner with one of the CIM program universities.

The revised pervious concrete research compilation may be downloaded from the foundation’s website at www.rmc-foundation.org. Hardcopies of the report also are available.