Define parameters for the PCI UHPC concrete model.

Parameter	Description
First peak (cracking) flexural strength, fcc	Stress level with first crack occurs. This value should be greater or equal to 1.5 ksi
Post-cracking design tensile strength, frr	Tensile strength that can be sustained by the concrete after first crack. This value should be at least 0.75 ksi
Fiber Length	Length of the steel fibers in the concrete matrix. Fibers should be a minimum of 1/2" in length.
Autogenous Shrinkage	Amount of autogenous (chemical) shrinkage in milli-strains (strain x 10^-3^).
Post-cure thermal treatment	Check this box if the concrete is subjected to post-cure thermal treatment.

Post-cure thermal treatment is defined as heating a UHPC element to a temperatur of 194 F for a period of 48 hours starting after the concrete has reached and age of 24 hours and before it has reached 14 days.