PDF Download: Jean Lafitte Auditorium Project Profile
Location: Jean Lafitte, Louisiana
Project: Jean Lafitte Auditorium – Slope Protection
System Installed: Concealed Grasscrete Systems
When Mother Nature overwhelms the landscape, then the landscape itself must change. Without flood control, nothing else matters. Such was the case in Jean Lafitte, Louisiana, when in 2008 Hurricane Ike destroyed the town auditorium while flooding thousands of homes and businesses in Jefferson Parrish. The existing auditorium was a community landmark because of its central location adjacent to Lafitte Library and both the elementary and middle schools. The Town was determined to rebuild and resolve site issues related to the floodplain.
The Federal Emergency Management Agency (FEMA) funded the new auditorium with the stipulation that before any new construction could begin, the site needed to be raised out of the floodplain. A local soil known as River Sand was used to raise the site by the required nine feet. A pile-supported building was designed for the new 18,000 sf auditorium. Because the elevation was raised so drastically it ultimately resulted in some drainage complications along the parking lot where a steep embankment transitions down to a ball field at the original grade. This was a complication just waiting for another, albeit entirely different in type, disaster.
The hill descends about 7 feet in just 12 feet of distance. With rain runoff in Louisiana’s damp climate, the hill side would likely quickly deteriorate. This could cause a potentially dangerous scenario in a highly-trafficked area between the schools and library. “The slope needed to be stabilized beyond the parking lot because of the steep grade and concerns about erosion,” says Robby Oswald, owner of Bomanite of New Orleans, the Bomanite Licensee contractor hired to resolve the issue. “The Grasscrete Slope Protection System was the ideal solution because it allows grass or other vegetation to grow within the voids. In this case it was covered with sod,” continues Oswald. The chosen solution is called the Grasscrete Concealed System, and Slope Protection.
Beyond the ability to be planted naturally, a key to Grasscrete’s success is its overall strength and durability. The Grasscrete molded-pulp former was used to allow cast-in-place concrete to be monolithically placed. When the forms are continuously reinforced with #4 rebar, the result is a compressive strength that can range from 4,500 psi to 12,000 psi depending on the specific mix used. That strength is identical to other flatwork concrete. Another important part of concrete’s strength is in the thickness of the slab. Grasscrete formers are designed for a 5 ½ inch thick concrete pan.