Concrete is the one major cost line you buy by volume, place in minutes, and can never re-measure. The cubic metres you ordered, the cubic metres on the delivery ticket, and the cubic metres actually in the structure are three different numbers, and the gap between them is where the money goes. Once the pour sets, the evidence window is closed for good. Capture at the pour is the only record that survives the dispute.
Concrete is the one major cost line on a construction site that behaves like nothing else you buy. You order it by volume. A third party batches it and delivers it. You place it in minutes. And the moment it sets, you can never measure it again. A short delivery of aggregate can be re-weighed tomorrow. A disputed plant hour has a meter reading that is still there next week. A pour that went in this morning against a theoretical volume nobody captured is gone. The structure is the only remaining evidence, and the structure cannot tell you how many cubic metres it took to fill it.
That is why the concrete argument is different from every other quantity dispute on site. It is not decided at month-end when the cert lands. It is decided at the pour, in the window between the truck arriving and the concrete going off, and that window is a few hours long. After that the numbers are fixed and the only question is who kept a record while it was still open.
The three numbers that never match
Every concrete pour carries three volumes, and they are almost never the same number.
- The theoretical volume: what the element should take, calculated from the drawing dimensions.
- The delivered volume: what the batching plant put on the ticket and invoiced you for.
- The placed volume: what actually ended up in the structure, after waste, spillage, over-excavation, form deflection and the pump line.
The theoretical figure comes from a drawing that assumes clean dimensions. The delivered figure comes from the party selling you the concrete. The placed figure is the one that matters commercially, and it is the one number nobody writes down. The dispute lives in the space between the three, and it opens on every pour whether anyone measures it or not.
Where the cubic metres actually go
The gap between ordered and placed is real, well understood, and mostly not dishonest. The ready-mix industry has a name for it: yield. The National Ready Mixed Concrete Association sets out the standard reasons an order does not fill the forms it was estimated to fill.
The industry reference on why ordered concrete and placed concrete differ. A one-eighth-inch error on a four-inch slab alone is a three percent shortage, and hardened concrete occupies about two percent less than its freshly mixed volume through air loss, settlement and shrinkage. The guidance is to order four to ten percent over the theoretical estimate to cover waste and contingency. CIP 8: Discrepancies in Yield (NRMCA).
So a well-run pour is expected to consume more than the drawing says. The problem is not that the gap exists. The problem is that without a pour-side record you cannot tell a legitimate four-to-ten percent yield allowance from a short load, a slump reject sent back, concrete diverted to another element to keep it moving, or a part-load you were billed full for. All of it averages into one project number that says there is a variance and says nothing about which pour it came from or which cause created it.
Where it closes
Concrete quantity is decided at the pour, not at the cert. Once it sets, the record either exists or it does not.
The Ghana specifics
The dynamics that widen the concrete gap are sharper here than in the textbook. Ready-mix runs on batching-plant lead times and road conditions, so a truck that arrives late arrives into a placement window that has already tightened. Ambient heat accelerates slump loss, so a load that was compliant leaving the plant can arrive out of specification and get rejected at the gate, and the question of who carries a rejected or returned load is exactly the kind of dispute that a gate-and-pour record settles in minutes and a memory settles never. Part-loads and long waiting times between trucks are common on sites feeding a single pump, and the waiting time and the part-load are both billable events that vanish unless they are captured as they happen.
On top of that, most sites run several elements and often several sites at once, and concrete gets moved between pours informally to avoid it going off in the truck. That is good operational discipline. It also means the cubic metres that left the ticket for element A and went into element B are invisible to both unless someone recorded the move at the moment it was made.
The illustrative cost
The per-pour number looks small until it repeats. A 200 cubic metre raft ordered at six percent over is 212 cubic metres on the ticket. If 205 cubic metres was genuinely placed and wasted, the 7 cubic metre difference at USD 130 per cubic metre delivered is USD 910 walked on a single pour. A project with fifty structural pours that each lose a comparable slice is not losing a rounding error. It is losing a line that would have shown up the day it happened if anyone had been measuring at the pour. (Illustrative model, your number from the audit.)
The same weak record compounds into the interim payment certificate. On a measured contract the concrete placed feeds the quantity the consultant certifies, and a placement figure evidenced only by the supplier ticket is a figure the consultant is right to cut. The cut is margin, and it walks on the strength of a record you never kept.
What closes the gap
- Every delivery captured at the gate against the pour it is for, tied to the ticket, the truck and the time, not reconstructed from a stack of dockets at month-end.
- Placed volume and genuine waste recorded at the pour while the pour is happening, so the third number finally exists.
- Rejected and returned loads, part-loads and waiting time evidenced at the event, so a contested load is proven rather than argued.
- Concrete moved between elements logged at the moment of the move, so it stays visible on both sides.
- The record captured offline first and synced when the signal returns, so a remote pour on weak 4G still produces evidence and a failed sync becomes a visible issue rather than a silent gap.
What this is not
This is not a theft-detection pitch, and it is not a claim that your batching plant is short-loading you. Yield loss is mostly ordinary: form deflection, over-excavation, air loss, honest waste, an order placed correctly high for contingency. The point is evidence, not blame. A structured pour record tells a legitimate yield allowance apart from a genuine short delivery, and it does it per pour, on the day, instead of averaging every pour on the project into one number that proves nothing. What you do with the pattern once you can see it is the operational decision.
Key takeaways
- Concrete is the cost line you buy by volume, place in minutes and can never re-measure, so the evidence window is the pour itself.
- Ordered, delivered and placed are three different cubic metre figures, and the placed figure is the one nobody writes down.
- Yield loss of four to ten percent is expected and legitimate, which is exactly why a short load hides inside it without a pour-side record.
- Once the pour sets, the argument is over. The only record that survives it is the one captured at source.
Frequently asked questions
- What is a concrete quantity dispute?
- It is a disagreement over how many cubic metres of concrete were actually placed in a structure compared with how many were ordered, delivered and invoiced. It arises because the theoretical volume from the drawing, the delivered volume on the supplier ticket and the real placed volume are three different numbers.
- Why can concrete quantities not be re-measured later?
- Concrete is placed as a liquid and hardens in minutes. Once it sets, the structure gives no reliable way to recover how many cubic metres it took to fill it, so the only usable record is the one captured while the pour was happening.
- What is concrete yield?
- Yield is the actual volume of concrete produced and placed. An under-yield means less concrete filled the forms than the volume ordered would suggest, caused by form miscalculation, waste, spillage, air loss, settlement and shrinkage. Ordering four to ten percent over the theoretical estimate is standard practice to cover it.
- Why do ordered and placed concrete volumes differ in Ghana?
- The standard yield reasons apply everywhere, and Ghana adds batching-plant lead times, heat-driven slump loss and rejected loads, part-loads and waiting time on sites feeding a single pump, and concrete moved informally between elements to avoid it going off in the truck.
- How does a weak concrete record affect payment?
- On a measured contract the concrete placed feeds the interim payment certificate. When the placed volume is evidenced only by the supplier ticket, the consultant is entitled to cut the quantity on weak evidence, and that cut is recovered margin lost.
- Is this about catching a supplier short-loading?
- No. Most yield loss is ordinary and not dishonest. The purpose of a pour-side record is evidence, not blame: it separates a legitimate yield allowance from a genuine short load, per pour and on the day, rather than averaging everything into one project figure.
- How does capturing at the pour help?
- Recording the delivery, the placed volume, any rejected or part-loads and any concrete moved between elements at the moment each happens produces the one number nobody usually writes down. That record settles a contested load or a certified quantity in minutes instead of leaving it to memory.
- How does Darikoda support concrete quantity control?
- Darikoda captures delivery and pour events at source, ties each to the element, the ticket and the time, works offline on weak connectivity and syncs when the signal returns, so the placed record exists before the concrete sets and survives the dispute.
Find where your concrete cost is leaking
Concrete variance is easier to close when it is captured at source. The free 30-minute Operational Audit maps where your pour evidence breaks: the deliveries, rejects and elements where the cubic metres are hiding, specific to your projects and contract structure. You keep the one-page map regardless of next steps.
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