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ACI Moment Coefficients-1

The document contains tables of moment coefficients for two-way concrete slabs according to the 1963 ACI code. It provides coefficients for negative moments from dead and live loads, as well as positive moments from dead and live loads, with coefficients given for various ratios of slab dimensions and different edge conditions represented by Cases 1 through 9. The coefficients are used to calculate design moments in two-way slabs based on the slab dimensions and loads.

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Joefer Cuetara
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237 views4 pages

ACI Moment Coefficients-1

The document contains tables of moment coefficients for two-way concrete slabs according to the 1963 ACI code. It provides coefficients for negative moments from dead and live loads, as well as positive moments from dead and live loads, with coefficients given for various ratios of slab dimensions and different edge conditions represented by Cases 1 through 9. The coefficients are used to calculate design moments in two-way slabs based on the slab dimensions and loads.

Uploaded by

Joefer Cuetara
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
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Download as PDF, TXT or read online on Scribd
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University of Negros Occidental Recoletos

Civil Engineering Department

ACI Moment Coefficients for Two-Way Slabs (1963 ACI)

Coefficients for Negative Moments in Two-Way Slabs


Case 1 Case 2 Case 3 Case 4 Case 5 Case 6 Case 7 Case 8 Case 9
Ratio
𝑙𝑎
𝑚=
𝑙𝑏

-Ca 0.045 0.061 0.033 0.050 0.075 0.071


1
-Cb 0.045 0.033 0.061 0.050 0.076 0.071
-Ca 0.050 0.065 0.038 0.055 0.079 0.075
0.95
-Cb 0.041 0.029 0.056 0.045 0.072 0.067
-Ca 0.055 0.068 0.043 0.060 0.080 0.079
0.9
-Cb 0.037 0.025 0.052 0.040 0.070 0.062
-Ca 0.060 0.072 0.049 0.066 0.082 0.083
0.85
-Cb 0.031 0.021 0.046 0.034 0.065 0.057
-Ca 0.065 0.075 0.055 0.071 0.083 0.086
0.8
-Cb 0.027 0.017 0.041 0.029 0.061 0.051
-Ca 0.069 0.078 0.061 0.076 0.085 0.088
0.75
-Cb 0.022 0.014 0.036 0.024 0.056 0.044
-Ca 0.074 0.081 0.068 0.081 0.086 0.091
0.70
-Cb 0.017 0.011 0.029 0.019 0.050 0.038
-Ca 0.077 0.083 0.074 0.085 0.087 0.093
0.65
-Cb 0.014 0.008 0.024 0.015 0.043 0.031
-Ca 0.081 0.085 0.080 0.089 0.088 0.095
0.60
-Cb 0.010 0.006 0.018 0.011 0.035 0.024
-Ca 0.084 0.086 0.085 0.092 0.089 0.096
0.55
-Cb 0.007 0.005 0.014 0.008 0.028 0.019
-Ca 0.086 0.088 0.089 0.094 0.090 0.097
0.50
-Cb 0.006 0.003 0.010 0.006 0.022 0.014

−𝑀𝑎 = −𝐶𝑎 𝑤𝑢 𝑙𝑎2


−𝑀𝑏 = −𝐶𝑏 𝑤𝑢 𝑙𝑏2
Where wu is the factored uniform load (DL + LL)
Compiled by JG Gutierrez
University of Negros Occidental Recoletos
Civil Engineering Department

ACI Moment Coefficients for Two-Way Slabs (1963 ACI)

Coefficients for Dead Load Positive Moments in Two-Way Slabs


Case 1 Case 2 Case 3 Case 4 Case 5 Case 6 Case 7 Case 8 Case 9
Ratio
𝑙𝑎
𝑚=
𝑙𝑏

+Ca dead 0.018 0.023 0.020 0.027 0.027 0.018 0.033 0.027 0.036
1
+Cb dead 0.018 0.020 0.023 0.027 0.018 0.027 0.027 0.033 0.036
+Ca dead 0.020 0.024 0.022 0.030 0.028 0.021 0.036 0.031 0.040
0.95
+Cb dead 0.016 0.017 0.021 0.024 0.015 0.025 0.024 0.031 0.033
+Ca dead 0.022 0.026 0.025 0.033 0.029 0.025 0.039 0.035 0.045
0.9
+Cb dead 0.014 0.015 0.019 0.022 0.013 0.024 0.021 0.028 0.029
+Ca dead 0.024 0.028 0.029 0.036 0.031 0.029 0.042 0.040 0.050
0.85
+Cb dead 0.012 0.013 0.017 0.019 0.011 0.022 0.017 0.025 0.026
+Ca dead 0.026 0.029 0.032 0.039 0.032 0.034 0.045 0.045 0.056
0.8
+Cb dead 0.011 0.010 0.015 0.016 0.009 0.020 0.015 0.022 0.023
+Ca dead 0.028 0.031 0.036 0.043 0.033 0.040 0.048 0.051 0.061
0.75
+Cb dead 0.009 0.007 0.013 0.013 0.007 0.018 0.012 0.020 0.019
+Ca dead 0.030 0.033 0.040 0.046 0.035 0.046 0.051 0.058 0.068
0.70
+Cb dead 0.007 0.006 0.011 0.011 0.005 0.016 0.009 0.017 0.016
+Ca dead 0.032 0.034 0.044 0.050 0.036 0.054 0.054 0.065 0.074
0.65
+Cb dead 0.006 0.005 0.009 0.009 0.004 0.014 0.007 0.014 0.013
+Ca dead 0.034 0.036 0.048 0.053 0.037 0.062 0.056 0.073 0.081
0.60
+Cb dead 0.004 0.004 0.007 0.007 0.003 0.011 0.006 0.012 0.010
+Ca dead 0.035 0.037 0.052 0.056 0.038 0.071 0.058 0.081 0.088
0.55
+Cb dead 0.003 0.003 0.005 0.005 0.002 0.009 0.004 0.009 0.008
+Ca dead 0.037 0.038 0.056 0.059 0.039 0.080 0.061 0.089 0.095
0.50
+Cb dead 0.002 0.002 0.004 0.004 0.001 0.007 0.003 0.007 0.006
+𝑀𝑎 𝑑𝑒𝑎𝑑 = +𝐶𝑎 𝑑𝑒𝑎𝑑 𝑤𝐷 𝑙𝑎2
+𝑀𝑏 𝑑𝑒𝑎𝑑 = +𝐶𝑏 𝑑𝑒𝑎𝑑 𝑤𝐷 𝑙𝑏2
Where wD is the uniform service dead load
Compiled by JG Gutierrez
University of Negros Occidental Recoletos
Civil Engineering Department

ACI Moment Coefficients for Two-Way Slabs (1963 ACI)

Coefficients for Live Load Positive Moments in Two-Way Slabs


Case 1 Case 2 Case 3 Case 4 Case 5 Case 6 Case 7 Case 8 Case 9
Ratio
𝑙𝑎
𝑚=
𝑙𝑏

+Ca live 0.027 0.030 0.028 0.032 0.032 0.027 0.035 0.032 0.036
1
+Cb live 0.027 0.028 0.030 0.032 0.027 0.032 0.032 0.035 0.036
+Ca live 0.030 0.032 0.031 0.035 0.034 0.031 0.038 0.036 0.040
0.95
+Cb live 0.025 0.025 0.027 0.029 0.024 0.029 0.029 0.032 0.033
+Ca live 0.034 0.036 0.035 0.039 0.037 0.035 0.042 0.040 0.045
0.9
+Cb live 0.022 0.022 0.024 0.026 0.021 0.027 0.025 0.029 0.029
+Ca live 0.037 0.039 0.040 0.043 0.041 0.040 0.046 0.045 0.050
0.85
+Cb live 0.019 0.020 0.022 0.023 0.019 0.024 0.022 0.026 0.026
+Ca live 0.041 0.042 0.044 0.048 0.044 0.045 0.051 0.051 0.056
0.8
+Cb live 0.017 0.017 0.019 0.020 0.016 0.022 0.019 0.023 0.023
+Ca live 0.045 0.046 0.049 0.052 0.047 0.051 0.055 0.056 0.061
0.75
+Cb live 0.014 0.013 0.016 0.016 0.013 0.019 0.016 0.020 0.019
+Ca live 0.049 0.050 0.054 0.057 0.051 0.057 0.060 0.063 0.068
0.70
+Cb live 0.012 0.011 0.014 0.014 0.011 0.016 0.013 0.017 0.016
+Ca live 0.053 0.054 0.059 0.062 0.055 0.064 0.064 0.070 0.074
0.65
+Cb live 0.010 0.009 0.011 0.011 0.009 0.014 0.010 0.014 0.013
+Ca live 0.058 0.059 0.065 0.067 0.059 0.071 0.068 0.077 0.081
0.60
+Cb live 0.007 0.007 0.009 0.009 0.007 0.011 0.008 0.011 0.010
+Ca live 0.062 0.063 0.070 0.072 0.063 0.080 0.073 0.085 0.088
0.55
+Cb live 0.006 0.006 0.007 0.007 0.005 0.009 0.006 0.009 0.008
+Ca live 0.066 0.067 0.076 0.077 0.067 0.088 0.078 0.092 0.095
0.50
+Cb live 0.004 0.004 0.005 0.005 0.004 0.007 0.005 0.007 0.006
+𝑀𝑎 𝑙𝑖𝑣𝑒 = +𝐶𝑎 𝑙𝑖𝑣𝑒 𝑤𝐿 𝑙𝑎2
+𝑀𝑏 𝑙𝑖𝑣𝑒 = +𝐶𝑏 𝑙𝑖𝑣𝑒 𝑤𝐿 𝑙𝑏2
Where wL is the uniform service Live load
Compiled by JG Gutierrez
University of Negros Occidental Recoletos
Civil Engineering Department

ACI Moment Coefficients for Two-Way Slabs (1963 ACI)

Coefficients for Shear in Two-Way Slabs


Case 1 Case 2 Case 3 Case 4 Case 5 Case 6 Case 7 Case 8 Case 9
Ratio
𝑙𝑎
𝑚=
𝑙𝑏

Wa 0.50 0.67 0.33 0.50 0.83 0.17 0.71 0.29 0.50


1
Wb 0.50 0.33 0.67 0.50 0.17 0.83 0.29 0.71 0.50
Wa 0.55 0.71 0.38 0.55 0.86 0.20 0.75 0.33 0.55
0.95
Wb 0.45 0.29 0.62 0.45 0.14 0.80 0.25 0.67 0.45
Wa 0.60 0.75 0.43 0.60 0.88 0.23 0.79 0.38 0.60
0.9
Wb 0.40 0.25 0.57 0.40 0.12 0.77 0.21 0.62 0.40
Wa 0.66 0.79 0.49 0.66 0.90 0.28 0.83 0.43 0.66
0.85
Wb 0.34 0.21 0.51 0.34 0.10 0.72 0.17 0.57 0.34
Wa 0.71 0.83 0.55 0.71 0.92 0.33 0.86 0.49 0.71
0.8
Wb 0.29 0.17 0.45 0.29 0.08 0.67 0.14 0.51 0.29
Wa 0.76 0.86 0.61 0.76 0.94 0.39 0.88 0.56 0.76
0.75
Wb 0.24 0.14 0.39 0.24 0.06 0.61 0.12 0.44 0.24
Wa 0.81 0.89 0.68 0.81 0.95 0.45 0.91 0.62 0.81
0.70
Wb 0.19 0.11 0.32 0.19 0.05 0.55 0.09 0.38 0.19
Wa 0.85 0.92 0.74 0.85 0.96 0.53 0.93 0.69 0.85
0.65
Wb 0.15 0.08 0.26 0.15 0.04 0.47 0.07 0.31 0.15
Wa 0.89 0.94 0.80 0.89 0.97 0.61 0.95 0.76 0.89
0.60
Wb 0.11 0.06 0.20 0.11 0.03 0.39 0.05 0.24 0.11
Wa 0.92 0.95 0.85 0.92 0.98 0.69 0.96 0.81 0.92
0.55
Wb 0.08 0.05 0.15 0.08 0.02 0.31 0.04 0.19 0.08
Wa 0.94 0.97 0.89 0.94 0.99 0.76 0.97 0.86 0.94
0.50
Wb 0.06 0.03 0.11 0.06 0.01 0.24 0.03 0.14 0.06
±𝑉𝑎 = 𝑊𝑎 𝑤𝑢 𝑙𝑎
±𝑉𝑏 = 𝑊𝑏 𝑤𝑢 𝑙𝑎
Where wu is the factored uniform load (DL + LL)
Compiled by JG Gutierrez

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