Experimental Investigation Of Cement Paste Coupon Strength Of Microwave Heating

In the medical sterilization, food drying, asphalt pavement repair and other fields, the applications of microwave technology is more common and relatively mature, but the research in the concrete and cement hydration application is still rare. Characteristics of microwave heating will be applied to decide the concrete feasibility of heat conservation. Water is the best medium to absorb microwave energy. After cement and water mixed cement slurry containing a lot of polar molecule formed and in the process of cement hardening, it is essential to maintain certain water. Therefore, the cement slurry is also a good medium to absorb microwave energy. The test shows that in the process of microwave heating and conservation the test block at the early strength rapidly improve as long as reasonable measures are taken and the intensity of its 28d and stand test block has no much difference. Compared with the heating methods buoyantly used, the heating speed is quick and in the test as long as the microwave heating is stopped the temperature doesn't cease immediately, and the thermal inertia is small easy to control the temperature.This paper focuses on two parts: First is used to study the impact of cement paste on the microwave absorption rate in scope of water-cement ratio (0.4 ~ 0.7), the results showed that: The cement paste in scope of water-cement ratio at 0.4 ~ 0.7, microwave absorption rate increases with increasing water-cement ratio. Second is putting the 0.28 water-cement ratio of cement paste test block separately in microwave maintenance and standard maintenance, comparing the intensity, the results showed that: Microwave heating can promote the maintenance test block of cement hydration, making the test block in a relatively short time to receive higher levels of intensity. The intensity of test block in microwave heating maintenance achieves 38.99MPa after 10h, it is higher than the intensity of test block in standard maintenance (32.97MPa) after 1d about 20%; putting the test block in standard maintenance after microwave maintenance, and its intensity of 1d achieves 48.93MPa, higher than the intensity of standard maintenance of 1d about 50%; and as long as taking right measures, its intensity after 28d is close to the intensity in standard maintenance.