Shear on bolts in brickwork
Shear on bolts in brickwork
(OP)
I have to beef up the support to a domestic timber floor due to increased loading.
My idea is to resin-bolt a 3"x3" steel angle to the brickwork immediately below the floor, using 3/8" bolts or threaded bar. I believe the shear on the bolts will not be the governing factor, it will more likely be the strength of the brickwork. The bricks are old
(+ 100 years) and of crushing strength probably around 1000 psi, in soft lime mortar.
Does anyone know of a method for evaluating the limiting shear on each fixing, or know of any publication
covering this?
thanks.
My idea is to resin-bolt a 3"x3" steel angle to the brickwork immediately below the floor, using 3/8" bolts or threaded bar. I believe the shear on the bolts will not be the governing factor, it will more likely be the strength of the brickwork. The bricks are old
(+ 100 years) and of crushing strength probably around 1000 psi, in soft lime mortar.
Does anyone know of a method for evaluating the limiting shear on each fixing, or know of any publication
covering this?
thanks.






RE: Shear on bolts in brickwork
RE: Shear on bolts in brickwork
RE: Shear on bolts in brickwork
A simple approach would be to use the same fixings and spacings as the timber which is currently fixed to the masonry. You will be more than doubling the shear strength since the capacity of the bolt in steel+masonry will be higher than the timber+masonry.
RE: Shear on bolts in brickwork
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Shear on bolts in brickwork
You could also check into testing the brick to determine the compressive strength which is the better way.
RE: Shear on bolts in brickwork
I believe there are methods to test that brick and mortar insitu, particularly for general compressive strength. Ask some local testing labs who do this kind of testing and work. The problem with your detail, bolts in shear and point bearing on the brick, is that that old brick and mortar are usually pretty soft, so it crumbles when you drill it and under those kinds of concentrated loads, or splits from the point bearing, or it literally vibrates loose during the drilling. Someone has to make a general assessment of the condition of the entire wall system, its strength and stability. Then, why not grout one angle 3x3x12", or some such, with one leg into a mortar joint. Then you have some substantial bearing area, not point bearing. Another angle above, with its horiz. leg outward is welded vert. leg to vert. leg and pushed up under the ledger. The original floor framing likely did provide lateral support for the wall, so you should some pay attention to that too, along with eccentricity of the above detail.
RE: Shear on bolts in brickwork
RE: Shear on bolts in brickwork
RE: Shear on bolts in brickwork
RE: Shear on bolts in brickwork