...
Modulus of rupture (LRFD 5.4.2.6)
Resistance factor for shear (LRFD 5.5.4.2)
Tensile and shear capacity of concrete (LRFD 5.8.2.2/5.4.2.8)
The following moduli of rupture are computed by Eriksson Culvert:
...
Normal wt. concrete, minimum reinforcement 0.37Öf’c 37(f’c)1/2 (5th Edition)
Normal wt. concrete, minimum reinforcement 0.24Öf’c24(f’c)1/2
Sand-lightweight concrete 0.20Öf’c20(f’c)1/2
All-lightweight concrete 0.17Öf’c17(f’c)1/2
All concrete types 0.24Öf’c 24(f’c)1/2 (7th Edition)
Normal-density concrete 0.40Öf’c 40(f’c)1/2 (CHBDC)
Semi-low-density concrete 0.34Öf’c 34(f’c)1/2 (CHBDC)
Low-density concrete 0.30Öf’c 30(f’c)1/2 (CHBDC)
For normal weight concrete, the resistance factor for shear, fv, is 0.90. For both types of lightweight concrete fv is set to 0.70, but has been increased to 0.80 in the 6th Edition, and to 0.90 in the 7th Edition. For CHBDC, fs (steel) is 0.90, and fc (concrete) is 0.80.
In accordance with LRFD Article 5.8.2.2/5.4.2.8, if lightweight concrete is specified, all occurrences of the term “Öf’c“(f’c)1/2” within LRFD Articles 5.8.2/5.7.2 and 5.8.3/5.7.3 are modified by the following factors:
...
The modulus of elasticity of the culvert concrete are computed by default using the following equations:
( LRFD 5.4.2.4-1) :
...
(LRFD 5.4.2.4-1, 7th Edition):
(
...
CHBDC 8.4.1.7):
...
where, wc, γc = unit weight (i.e., density) of concrete and f’c = specified concrete strength
The user can of course override the program calculation of this value . Further discussion of other materials properties is included under the appropriate sections within this chapter of the user manualthrough input on the material properties section of the ‘Culvert Properties’ window.