Concrete Cylinder Crush Types 1

[mfleming]

Hello.

I was wondering if anyone had resources to sites or documents on pictures and definitions of concrete cyclinder crush types.

We have a crushing lab at our work which we use to crush 4"x6" Conc. cylinders. We have charts and stuff, but lately we have been having questionable shears and I want to get more detailed information on the crush types so we can distinguish between the types.

Thanks

Matt

 

[jdonville]

mfleming,

In my experience concrete cyliders will generally fail either producing a discernable "shear cone" (icluding diagonal failure planes across the full width of the specimen) or by shearing vertically through the sample - sometimes this vertical shear is off-center of the central axis. This is not to be confused with incidental spalling of material from the surface of the cylinder.

The explosive failures seem to me to almost always produce a nice shear cone.

A useful detail to look for is to see if the cement breaks around the aggregate or if the aggregate itself splits in half.

PCA (

http://www.concrete.org)

sells publications dealing with all kinds of concrete technology. ACI (

http://www.aci-int.org)

offers training.

All you concrete busters, please correct me if I am mistaken in any of the above.

Jeff

Jeffrey T. Donville, PE
TTL Associates, Inc.

http://www.ttlassoc.com

 

[henri2]

ASTM C 39-99 Section 9.1.6 refers to Figure 2 Sketches of Types of Fracture

 

[jdonville]

henri2,

Thanks for providing the reference. I was about to post the same thing this morning after visiting our concrete lab.

Funny how many design guides do not include illustrations or photos of actual break patterns.

Jeff


Jeffrey T. Donville, PE
TTL Associates, Inc.

http://www.ttlassoc.com