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)	$\,f'c$ (psi)	$\,fc$ (psi)	$\,n$ (*)	$\,E_{c}$ (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)	$\,F_{y}$ = 60 ksi