Project Highlights

Roosevelt Bridge – Stuart, Florida

Florida has more than its fair share of corrosion concerns, not only due to being surrounded by ocean water, but also by the constantly warm climate where concrete experiences more drying / wetting cycles enabling a higher chloride absorption rate, thus intensifying the corrosion process. The Florida D.O.T. specifies an 8 to 9% silica fume addition rate for all concrete under salt water or in its splash zone. Amongst other concrete performance criteria, a maximum of 1,000 coulombs @ 28 days has to be achieved, as evaluated by the AASHTO T-277 Rapid Chloride Permeability test. In 1993 the Roosevelt Bridge in Stuart started construction in southeast Florida along US Hwy.1.

Mass concrete barged to location to Florida D.O.T. project at ocean inlet for new US 1 bridge

Roosevelt Bridge, Stuart, FL -1993

Mix Design Materials	lbs / yd3	kg / m3
Cement, Type I	451	267
Fly Ash ( 36 % replacement )	257	152
Silica Fume ( 8 % addition )	57	34
# 67 Limestone	1778	1054
Natural Sand	966	573
Water / Cementitious Ratio	0.35	0.35
Basic admixtures Type D retarder & AEA
High Range Water Reducer	1 gal / yd3	4.6 ltr / m3
28 day compressive strength	8,300 psi	57 MPa
56 day compressive strength	9,100 psi	63 MPa
Specification Requirement: very low permeability, i.e.<1,000 coulombs

PS: the above description and mix design pertains only to the Class V Special f’c=6,500 psi F-DOT mass concrete specification, of which approximately 10,000 cubic yards of concrete were furnished for pile caps.

roosevelt bridge, stuart, fl