Low Energy Accelerated Processing (LEAP) uses microwaves to cure concrete in as little as one-third of the time it takes with conventional steam methods. This technology, which theoretically could suit both precast and cast-in-place concreting applications, is the fruit of research by Australia's Commonwealth Scientific and Industrial Research Organization (CSIRO).
Using microwave technology to cure concrete is not a new concept, but the technology for implementation of the concept is. CSIRO has completed a pilot investigation successfully, and the results are impressive: Concrete samples cured with the LEAP method achieved a compressive strength that matched samples cured by conventional methods but with a much higher early strength gain.CSIRO scientists have moved from laboratory studies to prototypes and are now ready to begin production.
Steam is slower than curing by microwave and heats non-uniformly from the exterior to the interior of the concrete matrix, compromising long-term strength. Microwaves penetrate deep into the concrete and heat uniformly using feedback control.
What makes microwave-cured concrete beneficial is its very early strength. After just 45 minutes of microwave curing, concrete gains a compressive strength of 4351 psi in 5 hours. Microwave-cured concrete continues to show impressive strengths through the 91-day mark.