Tensile Bond Strength of Mortar to Brick

[anchorengineer]

Can someone tell me what the tensile bond strength mortar should have to the brick and where I can find it? Thanks!

Clarke Engineering Services, PC
Jobsite Engineering and Consulting

http://www.anchorengineer.com

 

[Iako]

What about Eurocode 6 for Masonry cheeck this

http://eurocodes.jrc.ec.europa.eu/doc/WS2009/3_pm_Morton.pdf

 

[Iako]

Also this could be useful

http://asaha.com/ebook/jMjE0MDU-/Design-of-Masonry-Structures-According-Eurocode-6.pdf

 

[Ron]

The tensile bond strength between mortar and brick can be highly variable and depends on several important factors, not the least of which is how well controlled the mortar quality is in the field. The rate of absorption of the brick, the water retentivity of the mortar, air content of the mortar and weather conditions at the time of placement all have significant influence.

To give a range of values, studies (by the Brick Institute) show that tensile bond strength can vary between about 15 psi and 100+ psi, with air entrained mortar being on the low side and non-entrained on the high side. Another factor is how well the brick is placed and tapped to leve...tapping increases bond, apparently because it removes entrapped air between the brick and mortar whereas hand pressure does not.

I would suggest that you contact the Brick Institute (now called the Brick Industry Association). They have a lot of technical resources....

Here's a link.....

Brick Industry Association (formerly Brick Institute)

 

[MiketheEngineer]

Pretty much ZERO --- at least that is what I would use.

 

[concretemasonry]

anchorengineer -

There are so many variables and no way to accurately inspect, sample and test what the actual is, assuming zero is conservative and usually not punitive since the tensile bond strength is rarely a problem. For brick, the actual strength to pull 2 brick brick apart in tension is affected by more things than an idealized lab test of small samples. - Like suction rates of the brick, coring and frogs. For specific applications for anchorage details, creative testing of actual assemblies would be needed.

What is the area of your concern (beside a vague lab test result) for your real application?

Dick



Engineer and international traveler interested in construction techniques, problems and proper design.

 

[anchorengineer]

The reason I asked the question was because a contractor forgot/didn't know to wet the bricks before he set them. The architect of record said they wouldn't bond propery because they were not wetted. The contractor was asking me for assistance. The only info I found in aci 530-05 was for shear stresses at the interfaces between wythes should not be greater than 5psi per section 2.1.5.2.2. The plan is to test the bond in the field to show that it meets a certain requirement. Any thoughts?

Clarke Engineering Services, PC
Jobsite Engineering and Consulting

http://www.anchorengineer.com