Hi jonjon3829. Sorry for this delay! I rarely come in here. You're basically right. I now that Internal vibration of UHPC is not recommended. But I don't put the vibrator into (inside) the concrete. It moves only on the surface of the top layer. This is necessary to level the complex shape of the casting. Believe me, this concrete with steel fibers is extremely dense and difficult to work with. Very low fluidity. Without the vibrator, it cannot be equaled in this complex casting.
At the UHPC, external treatment of the form with a vibrator is allowed. www.govinfo.gov/content/pkg/GOVPUB-TD2-PURL-gpo8373/pdf/GOVPUB-TD2-PURL-gpo8373.pdf
@@jonjon3829 Yes, without using steel fibers it would have been much easier. Although, the fibers reduce the fluidity a lot, I use them mainly to prevent the appearance of microcracks. The fibers will not increase stiffness, but increase tensile strength and compressive strength. I use fiber about 1.4 percent by volume. see these documents: Optimizing Ultra-HighPerformance FiberReinforced Concrete by Kay Wille, Antoine E. Naaman, and Sherif El-Tawil www.cnczone.com/forums/cnc-do-it-yourself-/466634-cnc-2.html#post2579742
Thank you for showing the entire process, the amount of work that goes into this is quite impressive
you are not supposed to vibrate nanodur, it leads to separation of components
Hi jonjon3829. Sorry for this delay! I rarely come in here.
You're basically right. I now that Internal vibration of UHPC is not recommended. But I don't put the vibrator into (inside) the concrete. It moves only on the surface of the top layer. This is necessary to level the complex shape of the casting. Believe me, this concrete with steel fibers is extremely dense and difficult to work with. Very low fluidity. Without the vibrator, it cannot be equaled in this complex casting.
At the UHPC, external treatment of the form with a vibrator is allowed.
www.govinfo.gov/content/pkg/GOVPUB-TD2-PURL-gpo8373/pdf/GOVPUB-TD2-PURL-gpo8373.pdf
@@ivanmitev7146 your mix was very dense I agree, I cast some test cubes myself with e45 recipe and no filler, I had no such issues.
@@jonjon3829
Yes, without using steel fibers it would have been much easier. Although, the fibers reduce the fluidity a lot, I use them mainly to prevent the appearance of microcracks.
The fibers will not increase stiffness, but increase tensile strength and compressive strength. I use fiber about 1.4 percent by volume.
see these documents:
Optimizing Ultra-HighPerformance FiberReinforced Concrete
by Kay Wille, Antoine E. Naaman, and Sherif El-Tawil
www.cnczone.com/forums/cnc-do-it-yourself-/466634-cnc-2.html#post2579742
@@ivanmitev7146 with proper chemistry you shouldnt get any microcracks, did you use superplasticizer and shrinkage reducer?