ACI References

Normalweight
concrete containing only coarse and fine aggregates that conformto ASTM C33.
Lightweight
concrete containing lightweight aggregate and having an equilibrium density, as determined by ASTM C567, between 90 and 115 lb/ft3.

Modulus of Elasticity
\( E_{c} = w_{c}^{1.5} 33 \sqrt{f'_{c}} \text{ psi for } 90\frac{lb}{ft^3}\leq w_{c} \leq 160\frac{lb}{ft^3} \) (ACI 318-14, 19.2.2.1.a)

For Normalweight Concrete

\( E_{c} = 57,000 \sqrt{f'_{c}} \text{ psi} \) (ACI 318-14, 19.2.2.1.b)

Modulus of Rupture
\(f_{r} = 7.5 \lambda \sqrt{f'_{c}} \text{ psi}\) (ACI 318-14, 19.2.3.1)

Steel Reinforcement

ASTM Standard Reinforcing Bars
Standard Bend Tie Bend
Bar Size, no. Nominal Diameter, in. Nominal Area, in2 Nominal Weight, lb/ft Inside Bend Radius, in. Outside Bend Radius, in. Inside Bend Radius, in. Outside Bend Radius, in.
3 0.375 0.110 0.376 1.125 1.500 0.750 1.125
4 0.500 0.200 0.668 1.500 2.000 1.000 1.500
5 0.625 0.310 1.043 1.875 2.500 1.250 1.875
6 0.750 0.440 1.502 2.250 3.000 2.250 3.000
7 0.875 0.600 2.044 2.625 3.500 2.625 3.500
8 1.000 0.790 2.670 3.000 4.000 3.000 4.000
9 1.128 1.000 3.400 4.512 5.640 - -
10 1.270 1.270 4.303 5.080 6.350 - -
11 1.410 1.560 5.313 5.640 7.050 - -
14 1.693 2.250 7.650 8.465 10.158 - -
18 2.257 4.000 13.600 11.285 13.542 - -
Per ft Area of ASTM Bars

Desired As: in2/ft

As,table/As < 1As,table/As < 2.0As,table/As > 2.0
As, in2/ft
Bar Size
Spacing, in. #3 #4 #5 #6 #7 #8 #9 #10 #11 #14 #18 Spacing, in.
4.0 0.330 0.600 0.930 1.320 1.800 2.370 3.000 3.810 4.680 - - 4.0
4.5 0.293 0.533 0.827 1.173 1.600 2.107 2.667 3.387 4.160 6.000 - 4.5
5.0 0.264 0.480 0.744 1.056 1.440 1.896 2.400 3.048 3.744 5.400 9.600 5.0
5.5 0.240 0.436 0.676 0.960 1.309 1.724 2.182 2.771 3.404 4.909 8.727 5.5
6.0 0.220 0.400 0.620 0.880 1.200 1.580 2.000 2.540 3.120 4.500 8.000 6.0
6.5 0.203 0.369 0.572 0.812 1.108 1.458 1.846 2.345 2.880 4.154 7.385 6.5
7.0 0.189 0.343 0.531 0.754 1.029 1.354 1.714 2.177 2.674 3.857 6.857 7.0
7.5 0.176 0.320 0.496 0.704 0.960 1.264 1.600 2.032 2.496 3.600 6.400 7.5
8.0 0.165 0.300 0.465 0.660 0.900 1.185 1.500 1.905 2.340 3.375 6.000 8.0
8.5 0.155 0.282 0.438 0.621 0.847 1.115 1.412 1.793 2.202 3.176 5.647 8.5
9.0 0.147 0.267 0.413 0.587 0.800 1.053 1.333 1.693 2.080 3.000 5.333 9.0
9.5 0.139 0.253 0.392 0.556 0.758 0.998 1.263 1.604 1.971 2.842 5.053 9.5
10.0 0.132 0.240 0.372 0.528 0.720 0.948 1.200 1.524 1.872 2.700 4.800 10.0
10.5 0.126 0.229 0.354 0.503 0.686 0.903 1.143 1.451 1.783 2.571 4.571 10.5
11.0 0.120 0.218 0.338 0.480 0.655 0.862 1.091 1.385 1.702 2.455 4.364 11.0
11.5 0.115 0.209 0.323 0.459 0.626 0.824 1.043 1.325 1.628 2.348 4.174 11.5
12.0 0.110 0.200 0.310 0.440 0.600 0.790 1.000 1.270 1.560 2.250 4.000 12.0
12.5 0.106 0.192 0.298 0.422 0.576 0.758 0.960 1.219 1.498 2.160 3.840 12.5
13.0 0.102 0.185 0.286 0.406 0.554 0.729 0.923 1.172 1.440 2.077 3.692 13.0
13.5 0.098 0.178 0.276 0.391 0.533 0.702 0.889 1.129 1.387 2.000 3.556 13.5
14.0 0.094 0.171 0.266 0.377 0.514 0.677 0.857 1.089 1.337 1.929 3.429 14.0
14.5 0.091 0.166 0.257 0.364 0.497 0.654 0.828 1.051 1.291 1.862 3.310 14.5
15.0 0.088 0.160 0.248 0.352 0.480 0.632 0.800 1.016 1.248 1.800 3.200 15.0
15.5 0.085 0.155 0.240 0.341 0.465 0.612 0.774 0.983 1.208 1.742 3.097 15.5
16.0 0.083 0.150 0.232 0.330 0.450 0.593 0.750 0.953 1.170 1.688 3.000 16.0
16.5 0.080 0.145 0.225 0.320 0.436 0.575 0.727 0.924 1.135 1.636 2.909 16.5
17.0 0.078 0.141 0.219 0.311 0.424 0.558 0.706 0.896 1.101 1.588 2.824 17.0
17.5 0.075 0.137 0.213 0.302 0.411 0.542 0.686 0.871 1.070 1.543 2.743 17.5
18.0 0.073 0.133 0.207 0.293 0.400 0.527 0.667 0.847 1.040 1.500 2.667 18.0