Concrete Pour Rate, Rate of Rise, and Delivery Cadence
How fast concrete rises in the forms at a given placement rate, plus pour time and truck cadence.
Example
You enter
- Crew placement rate (cy/hr) 20
- Form plan footprint (ft², wall = length x thickness) 100
- Total pour volume (cy) 44.44
- Ready-mix truck load (cy) 10
You get
- Rate of rise 5.40 ft/hr
- Pour duration 2.22 hr
- Delivery cadence 2.00 trucks/hr
Details, formula, and sources
The rate of rise (ft/hr) a placement rate produces in a given form footprint - the input formwork-pressure consumes - plus the pour duration and the ready-mix trucks-per-hour delivery cadence. Placing faster than the forms are designed for is how a blowout happens.
rate_of_rise_ft_hr = placement_rate_cyhr x 27 / form_plan_area_ft2; pour_hours = total_volume_cy / placement_rate_cyhr; trucks_per_hour = placement_rate_cyhr / truck_load_cy.
Rate-of-rise identity by name (volumetric placement rate over the form footprint); first-principles cubic-yard arithmetic; the rate of rise feeds ACI 347 formwork-pressure.
The rate-of-rise identity is public concrete-placement practice; the 27 ft^3/yd^3 constant is exact.
Estimate. AHJ and licensed professional govern.
Field names used by the API: placement_rate_cyhr, form_plan_area_ft2, total_volume_cy, truck_load_cy, rate_of_rise_ft_hr, pour_hours, trucks_per_hour
- Truck load 10 cy ready-mix load (default; the supplier's truck size governs)concrete-supply practice
- Volume constant 27 ft^3 per cubic yard (exact)physical fact