Wood "Hardness" 2

[Lumberman]

Lumber (usually of KD Lodgepole Pine and Spruce) is often used to make a protective wrap on large pipelines, to protect damage to the anti-corrosion coatings caused by rugged terrain, rock, etc.. during the lowering in and burial. This has been a common sense solution over the years. Now, in regions unfamiliar with this proven solution, Pipeline Engineers familiar with steel and concrete, etc.. are requesting "hard numbers" to support the case. All the Wood books I can search through have charts for wood properties, but the specific question I have been asked is "how much impact and wear damage does it provide?"

I am seeking an answer for the pipeline engineers. Despite their logical trust in the solution, Common sense will not cut it. Engineers need numbers!

If you wrap a pipe with Kiln Dried 2x4's, how much "mechanical protection" does it provide from a wood scientist's perspective? Impact/Compression Strength, etc..

Thanks in advance!

 

[SlideRuleEra]

You could consider using the "Hardness" of wood. A description of the test and table of the results for various species is presented in Chapter 4 of the USDA Forest Products Lab's "Wood As An Engineering Material" (free .pdf download) at:

http://www.fpl.fs.fed.us/products/publications/several_pubs.php?grouping_id=100&header_id=p

See the information beginning on page 4-3.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[Ron]

Agree with SRA...plus, the compression perpendicular to the grain...a common property of wood...supports this.

 

[msquared48]

Ron:

Only if your laptop is resting on wood.

Mike McCann
MMC Engineering

 

[Ron]

Mike...my laptop always rests on wood!! For some websites, more than others!

 

[Lumberman]

Yes, fellows, thanks for that . Those are the charts i have referred to.

Wood Thickness plus its density, in padding the force from the rocks, thereby preventing point load "spikes" onto the pipe, and so forth... isn't well explained with that data, at least to me (and my paygrade!)

For example, THICKNESS of the wood adds a measure of "depth" to the hardness. I am trying to interpolate that data to the field query in explaining the relative performance of kd lumber in holding back the potential damage of force transmittal to the pipe below the layer, when compared to, for instance, other methods like concrete coatings (both light duty and heavy duty) and proprietary plastic products like rockguard, tuff' nuff and so forth. They want comparables to these other materials in the field to fit kd wood into its cost/benefit slot in the pipe protection spectrum.

I think, too, that the data in those charts refer to the point at which, first, mild distortion of the wood begins... but at what point (Psi, Mpa?) do the point loads of rough fill material load through onto the pipe?

The wood book data doesn't immediately explain itself to that issue, or does it? I think that number may be very much different than the 500-600 psi range shown in the charts

??

Cheers!

 

[druminman]

My instinct would be that testing of resistance due to impact from projectiles would be good for comparison. These tests are done with respect to preventing damage due to hurricanes, perhaps by FEMA or someone working for them.

I've no experience other than having seen footage of a test whereby a 2x4 is launched from an air cannon at a sheet of plywood. It's quite impressive.

Hopefully someone here might know more about these tests or what the quantifiable results are.

Patrick

 

[Lumberman]

I discovered that broad body of work this morning surfing the net, and I agree it may have some merit, within the data, to pursue and add to the "query" . Thanks!

FYI, further reading and head-scratching has pointed me to the following areas for focus: I am seeking studies or data expansion (so I can relate it to the "query") on these terms I find in the "WOOD HANDBOOK":

"Impact Bending", "Tensile Strength perpendicular to grain", "Hardness", "Toughness", and Fatigue for KD Lumber (Pine and Spruce are the primary species of interests ... in sizes 2x4 and 2x6)

I welcome your ideas and pointers, and in addition I'll upload what I find in relation to this query, too.

Cheers!