Just saw some numbers that changed my mind about fiber mesh

I always thought fiber mesh was just a gimmick for small slabs... then I read a study from the ACI that said properly dosed fiber can cut crack width by 60% compared to no reinforcement. Has anyone else actually tested this on a big pour, like over 2,000 square feet?

3 comments

3 Comments

susanm565d agoTop Commenter

Yeah but @williamm82 the study controlled temp and slump, real world cracks are messy.

jenkins.reese5d ago

Huh, wonder how those fiber tests hold up with a frost heave underneath.

williamm826d ago

60% is a pretty big number. But I've seen lab results that don't always match the real world. Concrete acts different when you have hot weather, bad mix design, or a crew that doesn't place it right. I've seen fiber mesh jobs where the surface still looked like a dried up lake bed. The fibers might help control crack width but they don't stop the cracks from happening in the first place. Rebar and wire mesh still do a better job at holding the slab together when it moves. That ACI study you mentioned probably used perfect conditions. Perfect slump, perfect temperature, perfect cure. Real pours aren't like that. No contractor I know has time for that level of control on a big floor. Would like to see the same test done on a 5,000 square foot warehouse floor during a July heat wave. Bet those numbers would drop fast.