Concrete Pour Sequencing Calculator
Divide a slab into strips and get the volume, truck count and duration for each pour.
Quick answer
With the default inputs: Length 20 · Width 12 · Thickness 0.12 etc.Total volume 28.80 m³
Edit the inputs below to recalculate.Inputs
Result
Total volume
28.80m³
| Area | 240.0m² |
| Pour strips | 4strips |
| Volume per strip | 7.20m³ |
| Trucks per strip | 1loads |
| Duration per strip | 14min |
| Total duration | 0.96h |
| Trucks per hour | 3.33loads/h |
| Total trucks | 4loads |
Each strip must be placed before the previous one sets — typically 4-6 hours with ordinary concrete, less in hot weather. Leave and prepare construction joints between strips as the code requires.
Reverse: known result, work out one input
Enter a target result; the other inputs stay fixed and this one is worked out.
Formula
| Total volume | V = length × width × thickness |
| Strips | n = ceil(width ÷ strip width) |
| Volume per strip | V_strip = V ÷ n |
| Trucks per strip | N = ceil(V_strip ÷ truck capacity) |
| Duration per strip | t = V_strip ÷ rate × 60 |
A 20 m × 12 m × 0.12 m slab poured in 3 m strips with 9 m³ trucks at 30 m³/h: 28.80 m³ total, 4 strips of 7.20 m³ each — one truck and about 14 minutes per strip, 0.96 hours in total.
How to work it out
- Set the direction first: cut across the short side so the cold joint is as short as possible.
- Pours n = ⌈total width ÷ width per pour⌉. The last pour is usually narrower than a standard one, so do not divide equally.
- Volume per pour = pour width × element length × thickness, using the actual remaining width for the last one.
- Time per pour = volume ÷ actual output. Actual output is the pump's rated figure × 0.5-0.65, not the nameplate.
- Trucks per pour = ⌈volume ÷ truck capacity⌉, then check that the truck cycle can keep up with the placing rate.
Where it goes wrong
- Scheduling on the pump's rated output — 60 m³/h on the plate often means 35 m³/h in practice, so every pour overruns and cold joints follow.
- Dividing the total width equally — 20 m split at 3 m gives seven pours with a 2 m last one, not seven equal 2.86 m pours; truck counts and durations are all wrong.
- Checking only whether one pour can be finished, not whether the next lift can cover it before initial set — most pour-planning failures are cold joints, not incomplete pours.
Material and cost
Placing plans carry no direct cost but decide pump hire (8,000-12,000 per day for a boom pump), truck numbers and night-work premiums. Too few pours means cold-joint repairs; too many means the pump spends its shift repositioning and re-piping.
On site
- Keep each pour inside the initial set: 3-4 h at normal temperature, only about 2 h above 30 °C.
- Leave a 10-15 minute buffer between pours when ordering — better to let the pump idle than to wait for concrete.
- Measure the boom's real reach before fixing the plan, or you will discover the far corner needs re-piping mid-pour.
Basis
- GB 50666-2011 Code for construction of concrete structures, Section 8.3 (construction joints and post-cast strips)
- GB 50204-2015 Code for acceptance of concrete structures, Section 7.4 (joint treatment)
- GB 50164-2011 Standard for quality control of concrete (initial set and transport limits)
FAQ
Why split a pour at all?
Because supply runs out before the area does. If the placed area is larger than the trucks and pump can keep up with, the first concrete sets before the rest arrives and you get a cold joint with reduced strength and watertightness. Strip width should be derived from the volume that can be placed continuously.
What is the difference between a cold joint and a construction joint?
A construction joint is planned, placed where stresses are low, and prepared by scabbling, cleaning and wetting before the next pour. A cold joint forms unintentionally when supply stops; its position is arbitrary — often where stresses are highest — and it counts as a defect needing remedial design.
What truck capacity should I enter?
Common drum sizes are 6, 9 and 12 m³. Actual loads run 0.5-1 m³ below nominal and the last truck is rarely full, so rounding up on nominal capacity usually suffices. For large pours with long hauls, compute on 90% of nominal to avoid running dry mid-strip.
Cite this page
Use this format in reports, method statements or coursework. The link is permanent.
Building Calculator. Concrete Pour Sequencing Calculator. 2026-10-25. https://jianzhujisuan.com/en/concrete-pour-plan
Results are estimating aids only and are not a design basis. Construction and final accounts must follow the drawings, the applicable standards and an approved method statement. Anything affecting structural safety, shoring or falsework must be checked by a suitably qualified engineer.