| Summary: | The effect of microwave-accelerated curing on the permeability and drying shrinkage of Portland cement pastes was analyzed. Microwave-based curing is one of the technologies recommended for improving the drying shrinkage and permeability of cement pastes owing to its techno-economic advantages. Low-pressure accelerated microwave heating, also called accelerated dewatering, is an innovative technique that enhances the properties of Portland cement pastes such as high-strength Portland cement pastes. In this study, the effects of this improvement were investigated, including the impact of the pressure on the feed direction, microwave cavity, and different cement paste specimens for each treatment batch. Examination of the initial state of this treatment established the following. First, to avoid internal structure cracks, a delay time should precede the setting time (on average, 30 min after mixing). Second, increases in moisture and temperature within the microwave cavity should be minimal. It is concluded that low-pressure microwave treatment substantially improves the properties of Portland cement pastes by increasing the resistance to drying shrinkage and water permeability.
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