(11C) Concrete Beam Reinforcement Ratio and Area of Reinforcement

[buddyd16]

Recently acquired an HP 11c after having used TI's my whole life.

Here is a little program to calculate the required reinforcement ratio and required area of reinforcing steel.

setup:
Design Moment - Mu (ft-kips) STO 1
Cross Section Width - b (in) STO 2
Effective Depth to Tension Steel - d (in) STO 3
Concrete 28-day Compressive Strength - f'c (ksi) STO 4
Steel Yield Strength - fy (ksi) STO 5

Code:


Keystroke        Checksum        Comment
F LBL A        42,21,11    
RCL 1        45   1        Mu
RCL 2        45   2        b
RCL 3        45   3        d
G x^2        43   11        d^2
*            20    
.            48    
9            9    
*            20            0.9*b*d^2
/            10            Mu/0.9*b*d^2
1            1    
2            2    
*            20            conv. ft to in = 12*ans
STO 6        44   6        Ku
1            1    
RCL 6        45   6    
2            2    
*            20            2*Ku
RCL 4        45   4        F'c
.                48    
8            8    
5            5    
*            20            0.85*F'c
/            10            2*Ku/0.85*F'c
-            30            1 - (2*Ku/0.85*F'c)
√x            11            √1 - (2*Ku/0.85*F'c)
-            30            1-√1 - (2*Ku/0.85*F'c)
RCL 4        45   4        F'c
.            48    
8            8    
5            5    
*            20            0.85*F'c
*            20            (0.85*F'c)*1-√1 - (2*Ku/0.85*F'c)
RCL 5        45   5    
/            10            ρ
ENTER        36            copy ρ to stack
ENTER        36            copy ρ to stack
RCL 2        45   2        b
RCL 3        45   3        d
*            20    
*            20            As = ρ*b*d
G RTN        43   32        As in X register
                        ρ in Y register