Measurement of Foam-Concrete Temperature during Heat Treatment with Microwave Radiation

This paper addresses the high-priority goal of reducing the energy cost of heat-treating foam concrete slabs. We show that this problem is best solved using microwaves as a heat source. We discuss the main advantages of microwave curing over traditional techniques for curing foam concrete slabs, and develop a design for a microwave foam concrete slab curing unit. The microwave radiation sources used in the curing unit transmit the microwave radiation from rectangular waveguide openings used as radiating antennas. The temperature distribution on the surface of the foam concrete slab was calculated by the Huygens–Kirchhoff method; while the temperature distribution as a function of thickness within the foam concrete slab was calculated using the long-loaded-line method. We also propose a technique for measuring the temperature distribution within a foam concrete slab. We also describe the results from theoretical and experimental studies of the temperature distribution over the surface and through the cross-section of a vertical foam concrete slab 1500 mm wide, 1000 mm high, and 200 mm thick, with a density of 1000 kg/m³, and an electromagnetic field oscillation frequency of 2450 MHz. The experimental results indicated that microwave radiation was extremely efficient for curing foam concrete slabs. Microwaves can be used for curing products made with concrete, reinforced concrete, and polymer composite materials.