Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. MikeE55

    reinforcing for non-load bearing wall footings

    Yes, if you have a concrete wall above the footing then there is no reason to use the third bar in the top of the footing. Also true if you have horizontal bars in the masonry, but typically, we use horizontal masonry type reinforcing only. I haven't had any issues from a footing since I...
  2. MikeE55

    reinforcing for non-load bearing wall footings

    Kootk, The wall above the footing is typically masonry - usually a brick veneer with a 8" block backup. It is not integral with the slab. In the past I have seen engineers place two bars either 3" clear from the bottom or 2" clear from the top - since it is temperature reinforcing it is okay...
  3. MikeE55

    reinforcing for non-load bearing wall footings

    A few years ago my engineering firm starting placing longitudinal reinforcing for non-load bearing wall footings in two layers - two bars in the bottom of the footing, and one bar in the top. I am referring to footings that are typically about 24" wide by about 12" thick, and technically are...
  4. MikeE55

    advice on selecting a grade for old lumber

    Thank you RWW0002! The links were useful.
  5. MikeE55

    advice on selecting a grade for old lumber

    Does anyone have advice on selecting a grade for old lumber that was sawmilled before the current grading system? I am looking at engineering a renovation of a 100 year old building, constructed with lumber which is obviously a better grade than #2 SYP. Are there experts who can evaluate the...
  6. MikeE55

    Slab on Grade

    I have a copy - it was published by the Portland Cement Association in 1976.
  7. MikeE55

    spray concrete curing compound for floor slabs?

    The Sinak products look impressive, but they do not seem to be for interior slabs that will receive a floor finish. I know that wet curing is really the best way to go, but still wondering if that is the most commonly specified method for interior slabs. Most of the General Contractors in my...
  8. MikeE55

    spray concrete curing compound for floor slabs?

    I noticed that MasterSpec doesn't allow a spray cure compound for floor slabs to receive a floor covering, i.e. a form of wet cure is required. I know that dissipating spray curing compounds sometimes do not dissipate if they are not exposed to light and foot traffic, but they still seem to be...
  9. MikeE55

    Rotation and Deflection of Lintels

    I use L/600 or 0.3" max.
  10. MikeE55

    Masonry Expansion/Contraction Joints

    Definitely use control joints or you will end up with shrinkage cracks in the block. Brick will expand over time, but the cmu will shrink. I have seen many jobs where the control joints were omitted, and the cmu formed shrinkage cracks.
  11. MikeE55

    designing for missile impact on safe room

    I checked out the FEMA website for suggestions, but their design limits the wall height to 8'. My architect insists on using a 10' high wall, so I do not know if the FEMA design will be helpful. I am also exceeding their maximum horizontal wall dimensions by a few feet. I wanted to find a way...
  12. MikeE55

    designing for missile impact on safe room

    Thanks WARose. The slowdown distance may be a misnomer, since it came from a physics text where the example was a car crash test. I think it is the deflection, since the unit is in feet or inches. I'll check out Blodgett - that's a great book. Mike20793, thanks for the Texas Tech...
  13. MikeE55

    designing for missile impact on safe room

    I am designing a safe room for tornado loads and wondered how other engineers are calculating the force due to 2x4 missile impact. I think the appropriate formula is F = 1/2 x m x V x V / S, where S is the slowdown distance. The appropriate mass seems to be 15 lbs / 32.174 = 0.47 slugs, and...
  14. MikeE55

    crack pattern in precast beam

    I'm trying to figure out what has caused this crack pattern in a precast stadium beam. The cracks do not look like tension or shear cracks - maybe they are just shrinkage. The beam is about 3 feet deep and 14" wide. The predominant pattern is 3 or 4 longitudinal, with some random vertical...
  15. MikeE55

    Slab on grade & frost heave

    Turn down the exterior edges of the slab so that they extend below the frost line is the best way when you are in an area with a relatively shallow frost depth.
  16. MikeE55

    Soil Suction Forces

    Spats, I have calculated this design many times, and it sounds like you probably have too. I count on a certain amount of the slab working with my footing - usually at least a 3' cantilever from the footing, but maybe more, depending on how the slab is reinforced. I also count on a certain...
  17. MikeE55

    allowable vs ultimate coefficient of friction

    PEinc, yes, the way I have always calculated in the past is to use 1.5 x sliding force < (0.45 x DL). Or to use another value for friction factor based on the type of soil actually used. smvk3, sorry I jumped in without fully understanding your question. I think applying 0.6 to the DL to...
  18. MikeE55

    allowable vs ultimate coefficient of friction

    SMVK3, this is one reason why I don't like to get the coefficient of friction as provided by the geotech. If you design a retaining wall for 0.3, and then apply a factor of safety of 1.5 against sliding, you will end up with a very very conservative design. I asked this same question once of...
  19. MikeE55

    Beam design and deflection

    Be careful with the welding procedure. Your original sketch looks like a no-throat fillet weld. Maybe a bent plate in the shape of the two angles would work better, and eliminate the welding.
  20. MikeE55

    procuring special inspection services

    I'm curious as to the different ways to hire a special inspection firm. Many of our clients prefer to hire a qualified favorite firm and just pay their hourly costs on a monthly basis, but some clients prefer to have a "fixed fee." I have found that a fixed fee is nearly impossible to arrange...

Part and Inventory Search

Back
Top