Project Results

The chemical reactions involved in curing concrete are dependent on temperature. The curing process is most efficient when the temperature and hence the rate of hydration is kept constant.

Applying heat to the concrete can accelerate the setting process or, more importantly, keep the rate of hydration at a constant level. To work effectively, the application of heat must not result in the concrete losing water.

No energy input is required for the first 1-2 hours as the chemical reations are generating sufficient heat themselves. After that, heat can be applied at between 10°C and 20°C per hour: Below 10°C/hr is insufficient to replace the losses from the concrete; Above 20°C/hr can result in thermal shock or cracking.

The LOVACS project is now in the final stages of system trials and exploitation having considered the heat transfer, temperature control and optimal curing conditions of various thermal curing systems.

The Inditherm Insert System provides significant cost savings per unit volume over Hot Air and Steam systems:

Inditherm Insert System
£1.14/m3 (€1.67)
19 kWh @ £0.06/kWh (6 hours cure time)
Hot Air
£8.88/m3 (€13.05)
24 litres @ £0.37/litre (5 hours cure time)
Inditherm Insert System
£9.70/m3 (€14.26)
26.21 litres @ £0.37/litre (factory rate)

The Longley Precast provides the following Benefits and Cost Savings:

  • Early strength development (40N/mm2 in 18 hrs)
  • Potential to reduce cement to 370kg/m3 in summer and 390kg/m3 in winter (from 420 & 430kg/m3 resp)
  • Cement cost savings: €32k/yr
  • Running costs estimated to be ~€0.55/m3
  • Savings in gas for heaters: €3k/yr
  • SCC savings; reduced wear & tear
  • Improved working environment

At the present time, the LOVACS project has reached the following conclusions based on its trials:

  • The system works well, both as blankets and as modular inserts
  • Modular inserts require more power than blankets
  • Modular inserts are expected to have a longer live than blankets
  • Blankets aid hydration, even when not powered
  • Power consumption is 4 – 20% of traditional heating systems

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