Norchem - the largest producer of silica fume products in North America

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

roosevelt bridge, stuart, fl