Size is All Relative to the Area
Size is All Relative to the AreaNothing Left to Chance with Two Large Concrete Foundation Mat Pours for Ameristar Casino Expansion in St. Louis Area
STURTEVANT, Wis. (May 1, 2006): When it comes to gambling in the St. Louis area, Ameristar St. Charles can boast of being the first casino in Missouri. However, in comparison with the giant foundation mat pours found in this same area, there’s not much to brag about. That’s because soil conditions for most high-rise construction here is stable enough for conventional footings. The recent $240 million expansion of Ameristar St. Charles faced a significant exception with regard to soil stability.
Located in St. Charles County within the St. Louis metropolitan area, the addition of a 24-story hotel, conference center and parking garage to the existing casino was planned for the sandy Missouri riverfront in a flood plain.
Developing and pouring this foundation required some ingenuity, some soil modifications and a lot of concrete. The end result definitely gives a variety of construction companies around St. Louis some new bragging rights. This includes general contractor Walton Construction; geotechnical contractor Hayward Baker; structural formwork contractor Ceco Building Systems; flatwork and pumping contractor Ahal Contracting Company, Inc./Place-Crete Service; and ready mix supplier Breckenridge Material Company.
“It was a big deal for us, as this was one of the largest single cubic yard placements accomplished in our area within recent history,” says Keith Ahal, President and COO of Ahal Contracting and its subsidiary, Place-Crete Service.
With the distinction of pumping more St. Louis high-rises than any other single contractor in its area, Place-Crete was sub-contracted by Ceco to demonstrate the efficiency and reliability of concrete pumps in a region not accustomed to large mat pours. Nothing could be left to chance with this casino expansion project.
Before the Ameristar addition could begin, ground modifications were necessary to create a sound foundation at the casino’s riverfront site. Walton worked with Hayward Baker to perform Vibrocompaction to densify the sandy soil conditions for withstanding substantial weight.
The special soil-improvement technique, which is also unique to the area, was completed in about three months. The alternative, a drilled pier approach, would have potentially required a six to eight month process. With Vibrocompaction, over 3,000 compaction centers were created to depths of 33 ft. to 48 ft. below the planned elevation of the building’s foundation.
The 44,000 sq. ft. foundation was then divided into two large concrete mat pours. Each pour alone was sizeable enough to be considered large by standards of concrete yardage in this region. The first big pour required 3,950 cubic yards of concrete to be pumped at a five foot thickness and the second, 3,200 yards.
The first pour started promptly at 2:00 am on a weekday morning to avoid traffic, maintain a steady concrete supply and ensure no inconvenience was experienced by casino visitors with cash in their pockets. The job finished ten hours later.
Space was at a premium with access from just one side of the foundation’s perimeter. As a result, room was available for only three Putzmeister boom pumps. A BSF 36-Meter and a BSF 42X-Meter were provided from Place-Crete’s fleet and a BSF 47Z-Meter was sourced from owner James L. Whitehead’s concrete pumping fleet in neighboring Marion, Illinois.
To attain full concrete coverage to the farthest point about 140 feet away, the BSF 47Z-Meter was especially critical to the process. Its five-arm boom stretched to its full horizontal reach, the 47Z-Meter worked in unison with the other two pumps to deliver steady concrete output.
The ready mix supplier kept up the pace, using 55 mixer trucks from two central mix plants and one dry batch mix plant. They consistently discharged the concrete with its high content of slag into the three high output and high pressure boom pumps. The equipment gulped down the mix at a rate of about 400 cubic yards an hour until the last two hours of topping off.
“It was a well orchestrated plan,” says Mike Mills, Place-Crete’s Sales Manager. “Even though every mixer truck had to go through a low clearance parking garage beneath the casino and then drive across a specially cut out access road to discharge, we never had to wait for concrete on this pour.”
Not wanting to gamble on such a large pour, Place-Crete had a standby boom pump on site. But with the reliability and efficiency of the three pumps deployed, the extra machine was released when daylight broke.
“It really wasn’t that big of a risk, as we trust our Putzmeister equipment to provide smoother outputs with fewer problems,” says Mills. “Because of the trouble-free first pour, a backup pump wasn’t deemed necessary on the next.”
The second pour occurred at 1:30 am on a Friday morning, two weeks later. On this pour, the same three boom pump models were utilized. However, a Telebelt® TB 105 conveyor from Place-Crete’s fleet was also used. On this pour, the four machines had access from two sides of the foundation. The addition of the truck-mounted belt conveyor facilitated completion of the mat in only eight hours. This powerful machine can place volumes up to 360 cubic yards an hour.
Applauding the success of both pours as a result of the experienced people involved, Ralph Lincoln, Walton’s General Superintendent says, “A tremendous number of detailed meetings were held to coordinate both pours and keep everyone clued into what should occur. This involved several different sub-contractors, city officials and even local neighbors.”
“For the entire process to have been accomplished without one single hitch,” Lincoln adds, “is testament to the fact that everyone on the team wanted it to succeed.”
Ahal/Place-Crete was especially keen on ensuring the success of both pours. A flatwork business founded in 1945, the company expanded into concrete pumping in the early 1960s and became a Putzmeister dealer in 1987.
As a result of their vast industry experience, Ahal/Place-Crete realized the significant role the concrete boom pumps would play in the ultimate success of this uncommonly large foundation mat pour. The combination of exceptional equipment, highly trained concrete pump operators and an expert flatwork crew made the difference.
The Expanding Casino Operation
Established in 1994, Ameristar Casino St. Charles replaced its original riverboat casino with an all-new $360 million gaming and entertainment destination in 2002. Today, the site features 130,000 sq. ft. of gaming space along with seven themed restaurants and entertainment venues on a 52-acre complex.
Upon its fall 2007 completion, the expansion will feature a new 400-room all-suite hotel with a day spa, workout facility and indoor/outdoor pool, a 1,300 seat entertainment pavilion, 20,000 sq. ft. of meeting and banquet facilities and a 2,000 space parking garage.
Owner: Ameristar Casino St. Charles, a wholly owned subsidiary of Ameristar Casinos, Inc.
General contractor: Walton Construction – St. Louis, MO
Specialty geotechnical contractor: Hayward Baker – St. Louis, MO
Ready mix supplier: Breckenridge Material Co. – St. Louis, MO
Structural formwork contractor: Ceco Buildings Systems – St. Louis, MO
Flatwork contractor: Ahal Contracting Company, Inc. – Bridgeton, MO
Pumping contractor: Place-Crete Service, a subsidiary of Ahal – Bridgeton, MO
Equipment: Putzmeister BSF 36-Meter, BSF 42X-Meter and BSF 47Z-Meter truck-mounted concrete boom pumps and a Putzmeister Telebelt® TB 105