Temperature and strength prediction for the actual mix in the actual section — peak temperature and differential predicted to within about two degrees, before anyone is on site.
Once concrete is in the ground, the levers left are insulation, cooling and when you strike. They work, but they are reactive and every one of them costs programme. The decisions that actually govern peak temperature and differential — binder content, cement type, SCM replacement, placing temperature, section thickness, striking sequence — are all made before anyone is on site.
Thermal modelling moves the question to where those decisions are still cheap to change. It answers whether a proposed mix in a proposed section will stay inside its limits, and if not, which variable to change and by how much.
Most early-age thermal assessment in the UK is done with simplified spreadsheet methods — the analytical approaches set out in CIRIA C766 and its predecessors. They are well established and appropriate for a great many sections.
CONTEST is purpose-built prediction software. It complements those methods rather than replacing them: instead of working from a standard case, it computes how temperature develops through the actual section over time. That matters most where the simplified methods are weakest: complex geometry, changing boundary conditions, staged pours, and sections where the critical face is not the obvious one.
The model accounts for the heat of hydration of the actual binder, the geometry of the element, and the boundary conditions around it — formwork type, insulation, ground contact and the ambient temperature profile expected at the time of the pour.
Accuracy: within about ±2 °C against measured pours. That figure is what makes the model usable as a decision tool rather than an indication — a predicted peak of 63 °C against a 65 °C limit means something, and so does a predicted differential a few degrees inside its limit.
Two things: the mix designs under consideration, and the element dimensions. From those the binder's heat output and the section's thermal behaviour can both be established.
Where the question is not just temperature but whether the element will crack and how wide, the predicted thermal result feeds a crack width assessment carried out to CIRIA C766. The model gives the temperature history and differentials; the C766 method then takes restraint, strain capacity and reinforcement to crack spacing and width.
A model tells you what should happen. PROTEST records what did. Because the prediction is accurate to within about two degrees, the comparison between the two is meaningful rather than indicative — and that turns monitoring into something more useful than a compliance record.
When measured behaviour diverges from the model, something on site is not as specified. The mix delivered may not be the mix designed, insulation may not have gone on as planned, or a face may be losing heat faster than assumed. A thermal history that departs from its prediction is an early warning, and a more direct one than waiting on sample testing.
The modelling described here is delivered by OTB Concrete's engineering team as CONTEST — temperature and strength prediction for thermally sensitive structures. PROTEST is the monitoring half of it: where a project takes CONTEST, PROTEST is installed and managed as part of the service, so the prediction and the verification come from the same place.
PROTEST is also available on its own, for teams who already have their thermal control plan and need the monitoring and compliance record to go with it.
Early-age thermal analysis, differential predictions, thermal control plans and compliance reporting against specification limits — with PROTEST installed and managed as part of it.
CONTEST — temperature & strength prediction at OTB ConcreteSee PROTEST live with our engineers. We'll walk through a scenario tailored to your project type — no commitment required.
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