Concrete Strength with Fibermesh

[TomRK]

We have several concrete cylinder breaks from a project. Some of the mixes contained fibermesh, while others didn't, but otherwise the mixes were the same. The breaks from the cylinders containing the fibers were noticably higher than those without the fibers.

Will the fibers add appreciably to concrete compressive strength ?

 

[Ron]

Yes. Fibers, either polypropylene or steel, will enhance the compressive strength when added in amounts of about 1 percent by volume or more.

Why did some of the mixes have it and some didn't? Also, the mix designs should be a bit different between fiber and non-fiber as the fiber addition will typically decrease workability, thus some compensation is usually necessary when fiber is added.

 

[Blackhorse007]

yeap fiber in the concrete function linke a rebar, they will help to increase the strenght of the concrete. but if u add too much of fiber, the property would start to be come slightly unpredictable especially if the fibers are not mixed properly into the cement.

 

[Ron]

Well...actually fiber does not function like rebar and does not replace rebar. Fiber is a concrete mix enhancer. It is there to make the cement paste stronger and as such, helps to mitigate some forms of cracking.

 

[haynewp]

I am not a mix guru but the ones I have talked to have said the same. Fibers help control cracking but you should not depend on them for structural strength, though the suppliers may tell you differently and even offer you a free computer program.

 

[rapt]

haynewp,

You can develop computer programs that will give you any results you like. So everything can work. Doesn't mean that it is correct.

 

[Ron]

rapt...I think that's exactly what haynewp was implying! You're right.

 

[Blackhorse007]

Yeap Ron, thanks for pointing it out, it was not too well expressed

 

[haynewp]

Sorry, I thought it would be obvious.

When things are steep, remember to stay level-headed.
Horace