Since 1936, the Daytona Beach Bandshell has been a prime attraction on the "World's Most Famous Beach". While most visitors are drawn by the many scheduled entertainment events, others come just to see this beautiful coquina-rock landmark.
A few years ago, a modernization study concluded that while the bandshell was in "remarkably good condition", there were a few structural and cosmetic problems that needed attention. The city hired Burke, Bales, Mills and Associates of Orlando, Florida, to identify the specific problems and develop a repair strategy. Donald Moe, of Walter P. Moe and Associates, the structural engineer over-seeing the project, determined the most serious problem was structural cracks in the shell and over the doors and windows. He specified epoxy injection to repair the cracks.
APM Construction of Daytona Beach, was awarded the contract to make the repairs. Tod Desch, the site supervisor for APM, was concerned that traditional epoxy injection might be difficult and cause inadvertent problems. The coquina-stone (chunks of coral) is porous and irregular in shape, making it difficult to seal the surface. In addition, the stone was light colored and might be stained if resin would migrate through the pores in the stone. When Tod asked Construction Materials in Jacksonville to recommend appropriate repair materials, they suggested bringing in a Prime Resins' Sales Manager, to look at the problem.
Ed recommended using a "thixotropic" injection resin, Prime Rez 1600, and a technique called "cross stitching" to repair the cracks. Thixotropic resins have a consistency much like ketchup. They can be injected into cracks, but don't run or migrate once they are in place. Cross-stitching involves drilling holes from the surface through the crack at 45° angles, and bonding steel rods into the holes. This technique knits the structure back together and reduces the chances the cracks will continue to "grow".
In most areas of the bandshell, 1/2" holes were drilled 16" deep at intervals of 6 - 8". The directions of the holes were alternated so one passed through the crack from the left to the right and the next from right to left. After drilling, the holes were flushed with high pressure air to clean out any residual dust and then injected with Prime Gel 2000, a high strength epoxy gel adhesive. Immediately after injection, 3/8" stainless steel rods were inserted into each hole. Over the windows and doors, 3/8" holes were drilled 12" deep, and 1/4" stainless steel rods were used.
After the rods were bonded in place, Prime Rez 1600 was injected directly into the cracks.
The Daytona Beach Parks and Recreation Department was pleased with the results. Not only were the cracks repaired, but the structure was strengthened with virtually no staining of the beautiful coquina stone.
