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Concrete Joist Shear

[Subject Prev][Subject Next][Thread Prev][Thread Next] I'm looking at possible ways of increasing shear resistance in a tapered concrete joist system. The original design allowed for a depth of soil which is less than the present proposal which also includes some large rocks, trees and a pond.

So far I have been able to define a "light" weight soil (113pcf saturated), and am using records of test results to use a slightly higher in-place concrete strength.

The results of my analysis produce shear (and some bending) requirements somewhat greater than allowable (15%+). I've sharpened my pencil enough for now and would like any comments regarding possible solutions.

So you are aware, there is a possibility of replacing some of the soil volume with styrofoam (or other such material) but this may not completely solve the problem (nor is it preferred solution by the design team). Also, the rocks could become "Disney" like and significantly lighter if absolutely necessary. No immediate thoughts about using lighter water (nuclear), but I'm sure someone will bring it up. :-)

I've started looking at SIKA CarboDur for possible moment improvements but have no hands-on experience.

Would appreciate any comments.

Barry H. Welliver