specifications - FAACO - Federal Aviation Administration Contract ...

FTWIC-2235June, 2009L. Clean the surface of non-skid, non-slip surfaces, where specified, and prepare forspraying, brushing or rolling with an epoxy compound. Immediately after applying theepoxy, broadcast the aggregate by hand or machine at l.5 pounds per square yard. Theaggregate may be a proprietary mixture or aluminum oxide, or silicon carbide, or roofinggranules, or silica sand or trap rock passing the #50 sieve and retained on the #60 sieve.Adhere to the Manufacturer's recommendations when using proprietary products.3.10 PLACEMENT IN FOUNDATIONS:Place concrete in deep foundations so that segregation of the aggregates or displacement of thereinforcement is avoided. Provide suitable chutes or vertical pipes. When footings can be placedin dry foundation pits without the use of cofferdams or caissons, forms may be omitted and theentire excavation filled with concrete to the elevation of the top of footing. The placing ofconcrete bases above seal courses is permitted after the forms are free from water and the sealcourse cleaned. Execute necessary pumping or bailing during concreting from a suitable pumplocated outside the forms.3.11 PLACEMENT IN PIERS:A. Start concrete placing within eight (8) hours after completion of augering and inspectionof shaft. Concrete to be placed in dry pier openings, with or without casings, shallcontain set retarders and water reducing agents. Use air entraining admixture in drilledpiers.B. Concrete placing shall be continuous from the beginning of placing in the bottom to thetop. Time intervals are allowed for vibrating or rodding, pulling casing, placing formsand other necessary operations.C. Place concrete through a tremie tube to prevent the segregation of concrete materials andunnecessary splashing on the reinforcing steel cage. The tremie shall be in sections topermit the discharge end to be raised as placement progresses. The maximum allowablefall for the concrete from the end of the tremie shall be 5 feet.D. Wherever casing is used, extend it above the grade of the finished shaft to provide excessconcrete placement for the anticipated slump from the casing removal.E. Where a cap block or groundline strut is shown to be placed at the top of the pier, and thecap or strut is shown to be placed monolithically with the pier, a time interval is allowedfor placing the required form and reinforcing after any necessary casing removal.F. After placement is completed, cure the top surface and treat construction joint area, asspecified.G. If it is clearly demonstrated that ground water cannot be sealed off because of the natureof the foundation formation, the pier concrete may be placed through water using thefollowing procedures:1. Clean the bottom of the pier hole of mud and loose material. Pump water outimmediately ahead of concrete placing to insure that the bottom is in satisfactorycondition. Flowing water is not permitted.03300-23