Does any have any insight or experience with concrete actually decreasing in strength from 28 to 56-days? We are having three different entities test cylinders from a precast plant independently and all are coming up with similar results. 28-day strength is around 10-12,000 psi compression and...
I'm trying to find documentation for sodium silicate when used as a backfill grout additive. It is commonly used in that application, but there is no ASTM test or quality assurance measure that I can find to check it's performance, either alone or when incorporated into the grout. I am already...
I'm designing some flag poles for a banner that stretches across a street. I've reviewed the ANSI/NAAMM 1001-07 document which addresses wind forces on flags quite well. It does not address wind forces on a banner supported on both sides, which acts more like a parachute than the wind forces on...
I have a project with some existing concrete piers supporting existing pipe columns that support equipment. For non-engineering reasons, the supports are being relocated a few feet away from the center of the pier. The loads are relatively small (1 to 3 kips) vertically and laterally and the...
I'm in a debate right now with a software manufacturer, my stand is that the ASCE Omega overstrength factor is not applicable to finding a 1.5 or 1.3 factor of safety for overturning of a foundation.
Generally it's my contention that overstrength is only applied where specifically stated in...
Does anyone have any data or general knowledge of the effects of temperature on the friction coefficient of metals? In particular steel on oil-impregnated brass? Thanks for your help!
Does anyone know if any additional conversion factors are required to arrive at appropriate units using the equation for Sand/Oil interceptors for auto washers. The specific equation is on page 427, we can't get the units to work out with the given equation from what we can figure out. We are...
I've designed the foundation and attachment for a 60' tall wind turbine for a rural homeowner in Nevada. The tower is factory built and designed, but I was required to prove by calculation the design was adequate, which is what I did.
My question is the plan checker at the building department...
I have a 20' concrete retaining wall I've designed and is being constructed. The contractor is hitting what he thinks is bedrock (most likely it is) near the obviously large footings for the wall. He wants to tie in to the bedrock in lieu of getting all the rock (most likely granite and basalt)...
I have an attorney who is looking to test the coefficient of friction on some wood for lawerly reasons. Has anyone ever seen a standardized test for measuring friction on a building material? It wouldn't be hard using engineering principles to come up with something myself, but I would like to...
I'm designing foundations for a series of flag pole-style wind turbines poles with vertical vanes. In using ASCE7-05 method II wind design I'm interpreting the Cf of "other structures" as coming from Fig 6-22 "Open signs and Lattice Framework". However I could make the argument that I could use...
Is anyone familiar with finding the "elastic section modulus" called Sm noted in ACI 318-05 in the plain concrete section, chapter 22? I can find no specific calculation for it; would I assume a regular S section modulus?
Help, I'm trying to determine edge and center uplift on a silty sand that is very saturated.
The project will be pt slab-on-grade. The literature I can find isn't very explicit about these uplifts with respect to sandy soils. There's very little plasticity, I think one test out 20 had any PI...
