Workers with R.F. Concrete Construction Co. of Vero Beach were pouring and spreading 14,000 square feet of concrete Monday for the JCPenney store under construction at the Crystal River Mall. The floor of the store will measure 52,000 square feet. The Edward J. DeBartolo Corp. is building the structure, which will be turned over to JCPenney in June. The finished store is scheduled to open in early October.