Scrub Ecosystem Viewed from New Concrete Path Febuary 2005

Concrete pumped through 1000 ft of ‘hose’ to prevent damage to rare Florida ecosystem

STURTEVANT, Wis. (February 2, 2005) – Nestled in the heart of Palm Beach County, Florida on the shores of the Intracoastal Waterway is the quaint town of Hypoluxo. Although a small town of only 2,000 inhabitants, it boasts the distinct honor of being home to one of Florida’s oldest, rarest and most endangered ecosystems – scrub.

Scrub is a dry ecosystem regulated by fire and found on higher, sandy ground – valuable real estate no longer in abundance. The nature of this land made it the first choice for fast-paced urban developments because it reduced the added expense of fill. Estimates indicate that less than two percent of the original scrub in Palm Beach County remains.

Palm Beach County purchased the 97-acre Hypoluxo Scrub area on the town’s western edge in December 1999. Today, it is home to several protected animals including the threatened Florida scrub jay and the gopher tortoise. This is in addition to several natural and exotic plant species. To ensure the ecosystem’s preservation, a $1.6 million project was undertaken late last fall.

One aspect of the project involved construction of a winding concrete sidewalk. At over 1,900 linear feet long, the sidewalk was essential because the natural area is open to the public.

Kristen Nelson-Sella, Site Manager for the Hypoluxo Scrub said, “The purpose of the looped sidewalk is to provide visitors with a clearly defined walking trail for specifically viewing the more sensitive plants. Trail markers and brochures along the path will enable people to discover what makes this ecosystem so special.”

While a major objective for a sidewalk is to prevent environmental damage by strolling visitors, construction crews had a similar challenge of avoiding disruption to the foliage during the building process. Taking extreme care not to harm plant growth, the concrete contractor Adeimy Concrete of West Palm Beach, formed up the winding concrete walkway – a challenge in itself because of unclear reference points in the open and sandy wilderness.

Obviously, chuting the concrete was not an alternative, as driving ready-mix trucks over the vegetation to the different pour points would cause excessive damage. Therefore, pumping was the only logical choice to avoid disruption to the scrub.

Adeimy Concrete, in turn, relied on Quality Concrete Pumping of Coral Springs, Florida for their expertise and high performance equipment to pump concrete in an atypical approach – one that would not interfere with the natural habitat.

For the initial pour, Quality positioned a Putzmeister trailer-mounted concrete pump in the middle of the scrub using an existing management road made of semi-compacted sand.

From this point, Quality positioned 150 ft of steel pipe – the longest straight portion of pipe possible on the entire project. To further accommodate the zigzagging concrete path, flexible 2-inch rubber hose was used on the final 850 ft to the pour.

The job demanded the flexibility of rubber hose to keep the delivery line within the curving forms and off the scrub’s foliage. This first steel pipe and hose combination was the starting point for creating the five-foot wide walkway equivalent to about six city blocks.

For the second phase of the pour, the trailer pump was situated farther down the same access road with an unbelievable 1000 ft of hose (no pipe) in the other direction to continue its circular shape. The third and smallest pour was from the main entrance, requiring 700 foot of hose to connect the previous pour and finish the lasso-shaped path.

According to George White, Vice President of Quality Concrete Pumping, “The real challenge of this job was pumping concrete 1000 ft through two-inch rubber hose. It really takes a high performance trailer pump to do that.”

To meet these needs, a Katt-KreterTM was chosen to push the concrete through the two-inch hose at the excessive distance required using high pressure up to 1150 psi (79 bar). With a turbo-charged 100-hp Deutz engine, the Putzmeister trailer pump clearly had enough horsepower for all three concrete pours, which totaled about 200 cubic yards of concrete.

Confident about the Putzmeister products he uses and promotes, George says, “Pumping this project put the Katt-Kreter to a real test. The unit was pushed to its maximum specs and passed with flying colors.”

Nelson-Sella notes, “I was on site during the entire process to ensure the equipment had minimal impact on the scrub. I was really impressed with Quality’s pump operators. They clearly understood the importance of keeping the concrete in the forms and not disrupting the sensitive habitat. Plus, they were experts at handling the mix so it didn’t get stuck in the hose while pumping, which could have caused havoc to the site.”

According to Jim Henegar, co-owner of Miami-based Thomas Machinery, the Putzmeister equipment dealer in the area, “The job would have been newsworthy at 500 ft of hose. That’s because most pumping companies don’t like to work with hose beyond 300 ft, as it has three times more resistance than steel pipe. Clearly, Quality has the competence to handle this more challenging approach to placing concrete.”

The only major obstacle encountered was when the soft sand conditions proved problematic for ready-mix trucks to deliver the specified 3500-psi pea rock mix. On the initial pour, the first mixer made it out to the area without fail, but the second truck wasn’t as fortunate. It got stuck in the sand’s sugar-type consistency before being able to discharge its 10-yard load of concrete.

Unable to unload the concrete just anywhere in the endangered scrub and with no water available, the mixer truck had to be rescued from the scrub’s grasp by another vehicle. In total, it took over 90 minutes to free the mixer truck; and consequently, the concrete was rejected. From that point on, Rinker Materials of Lakeworth, Florida only sent specially equipped trucks with central tire inflation, which helps vehicles maneuver in soft sand without getting stuck.

Henegar says, “The central tire inflation is a great feature that is also offered on Putzmeister truck-mounted concrete pumps. By simply flipping a switch, tires are deflated for greater traction in the ‘sugar sand’ found in our region. Then it automatically re-inflates the tires once on solid ground.”

Nelson-Sella comments, “Of course, it was very worrisome when the truck got stuck, but the crew came up with an alternative that provided the least impact to the scrub. Fortunately, it was also in an area of exotic plants, which tend to overpopulate.”

Jeff White, President of Quality Concrete Pumping concludes, “Counted on for our experienced operators and reliable equipment, we are requested to work on some rather unusual jobs. Of course, we accept the challenges – it keeps business interesting.”

SPECS Concrete contractor: Adeimy Concrete – West Palm Beach, FL Pumping contractor: Quality Concrete Pumping – Coral Springs, FL Ready-mix supplier: Rinker Materials – Lakeworth, FL Equipment: Putzmeister Katt-Kreter™ trailer-mounted concrete pump Pumping equipment dealer: Thomas Machinery, Inc. – Miami, FL