ACI 318 Code Equations Non-Homogeneous => Why?

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ELASTIC-1

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CERM CH.50

INTRODUCTION

"Many of the code equations are not homogeneous - the units of the results cannot be derived from those of the inputs."

I don't know why but this bothers me and makes me cringe. How did the code end up this way?

 

Ble_PE

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I'm not an expert, but I'll give it a shot. Concrete is a non-homogeneous material and therefore many of the equations from mechanics of materials that were derived for homogeneous materials such as steel won't work for concrete. For this reason, most of the equations are empirical and are backed by years of research.

 

MA_PE

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^x2

Some equations are based on best fit curves of test data, not theoretically derived relationships, so the additonal coefficients screw up the units.

Things are not always linear elastic (see what I did there?)

 
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kozac

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I was actually pondering that quote myself as I was always taught to "watch my units"..

 

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