Mass Concrete Temperature Calculator
Placement temperature, adiabatic rise and peak temperature in one step.
With the default inputs: Cement 300 kg/m³ · Cement temp 40 ℃ · Sand 700 kg/m³ etc.Expected peak core temperature 61.6 ℃
Edit the inputs below to recalculate.Inputs
Result
| Placement temperature T0 | 29.2℃ |
| Adiabatic rise Th | 43.2℃ |
| Dissipation factor k | 0.75 |
| Actual rise | 32.4℃ |
| Surface temperature target | 36.6℃ |
| Core-surface differential limit | ≤25℃ |
Placement temperature is the weighted mean of ingredient temperatures (mixing heat ignored); adiabatic rise uses Th = mce·Q/(c·ρ) with c = 0.97 kJ/(kg·K) and ρ = 2400 kg/m³. The dissipation factor is empirical - thicker pours retain more heat. The 25 ℃ core-surface limit follows GB 50496, with cooling rate usually kept under 2 ℃/day. A real thermal control plan (sensor layout, curing, cooling water) must be prepared separately.Peak above 60 ℃ - use fly ash or slag to cut cement, shade and wet the aggregate, ice the mixing water, and consider embedded cooling pipes.
Reverse: known result, work out one input
Enter a target result; the other inputs stay fixed and this one is worked out.
Formula
| T0 = Σ(mi·ti) / Σmi | weighted by mass |
| Th = mce·Q / (c·ρ) | c = 0.97, ρ = 2400 |
| Tmax = T0 + Th·k | k = 0.60 / 0.75 / 0.85 by thickness |
| surface ≥ Tmax − 25 ℃ | differential control |
How to work it out
- Compute placing temperature: weight × temperature for cement, sand, stone and water, summed and divided by the total heat capacity. Ice or chilled water is the most effective lever.
- Compute adiabatic rise: Tmax = W·Q ÷ (c·ρ) × k, with W the cement content, Q the 7-day heat of hydration, c = 0.97 kJ/(kg·°C) and ρ = 2,400 kg/m³.
- k depends on pour thickness: 0.60 below 1.5 m, 0.75 for 1.5-3 m, 0.85 above 3 m — thicker sections shed heat more slowly and approach adiabatic.
- Peak temperature = placing temperature + adiabatic rise × k.
- The governing limits are core-to-surface ≤25 °C and surface-to-air ≤20 °C. Exceeding them means more insulation or casting in layers.
Where it goes wrong
- Computing only the adiabatic rise — placing at 35 °C plus 40 °C of rise gives 75 °C, and no amount of heat control saves that; the placing temperature must come down first.
- Using 28-day heat of hydration — the peak in mass concrete arrives at 3-5 days, so the 7-day value is required; using 28-day underestimates by 20-30%.
- Reading the limit as peak minus air temperature — what is controlled is the differential within the concrete (core versus surface). With good surface insulation, a 40 °C gap to air is fine.
Material and cost
Monitoring (logger plus thermocouples) 10,000-20,000 per project; insulation 10-20 per m²; ice batching adds 15-30 per m³; embedded cooling pipes 40-60 per m. Remediating thermal cracking, by contrast, runs to six figures and is rarely complete.
On site
- Hold the cooling rate to 2 °C per day or less — a sudden drop does more damage than a high peak, because stress follows the gradient.
- Cast in 0.5-1.0 m layers, each closed before initial set: it sheds heat and prevents cold joints at the same time.
- Place sensors at the core, near the surface (50 mm below) and mid-depth; measuring only the centre measures nothing useful.
Basis
- GB 50496-2018 Standard for construction of mass concrete (temperature limits and sensor layout)
- GB 50666-2011 Code for construction of concrete structures, Section 8.5
- GB 50204-2015 Code for acceptance of concrete structures, Section 7.4
FAQ
Does cement temperature really matter that much?
What is the difference between adiabatic and actual rise?
Why the 25 ℃ core-surface limit?
Cite this page
Use this format in reports, method statements or coursework. The link is permanent.
Building Calculator. Mass Concrete Temperature Calculator. 2026-10-25. https://jianzhujisuan.com/en/concrete-temp-control