# 751.4 Reinforced Concrete Design Properties

## 751.4.1 Reinforced Concrete

Classes of Reinforced Concrete

Below are classes of concrete for each type or portion of structure:

 Box Curlverts B-1 Retaining Walls B or B-1 Superstructure (General) B-2 Curbs and Parapets B-1 Safety Barrier Curbs B-1 Median Barrier Curbs B-1 Sidewalks B-2 Raised Median B-2 Slabs B-2 Box Girders B-2 Deck Girders B-2 Prestressed Precast Panels A-1 Prestressed I - Girders A-1 Prestressed Double -Tee Girders A-1 Integral End Bents B-2 (Above lower construction joint) Semi-Deep Abutments B-2 (Above construction joint under slab) Substructure (General) B (*) Integral End Bents B (Below lower construction joint) Semi-Deep Abutments B (Below construction joint under slab) Intermediate Bents B Columns B (*) Intermediate Bent Columns, End Bents B-1 (Below construction joint at bottom of slab in Cont. Conc. Slab Bridges) Footings B Drilled Shafts B-2 Cast-In-Place Pile B-1

(*) For continuous concrete slab bridges or in special cases when a stronger concrete is deemed necessary by the designer, use class B-1 for columns and end bents below construction joint at bottom of slab.

Unit Stresses of Reinforced Concrete
Class of Concrete Aggregate Maximumsize (Inches) Cement Factor (barrels percubic yard) ${\displaystyle \,f'c}$ (psi) ${\displaystyle \,fc}$ (psi) ${\displaystyle \,n}$ (*) ${\displaystyle \,E_{c}}$ (ksi)
A-1 3/4 1.6 (Min.) 5,000 2,000 6 4074
B 1 1.4 (Min.) 3,000 1,200 10 3156
B-1 1 1.6 (Min.) 4,000 1,600 8 3644
B-2 1 1.875 (Min.) 4,000 1,600 8 3644
(*) Values of n for computations of strength only.

Reinforcing Steel
Reinforcing Steel (Grade 60) ${\displaystyle \,F_{y}}$ = 60 ksi