Study on the preparation and properties of high-performance foamed cement by multi-factor optimization

The promotion of high-performance foamed cement in engineering is consistent with the objectives of energy conservation and sustainable development. In this work, the effects of the water-binder ratio, foam-grout ratio, mineral powder content and magnesium oxide content on the performance of foamed cement were studied. Highperformance foamed cement was prepared considering the above four factors. The results indicated that the pore structure of the foamed cement was effectively modified by adjusting the water-binder and foam-grout ratios, while its compressive strength increased and its setting time decreased when mineral powder and magnesium oxide were added. Pore structure and scanning electron microscopy experiments revealed that the surface of the high-performance foamed cement was covered with many hydration products of mineral powder and magnesium oxide, resulting in a more compact and uniform structure. Simultaneously, these hydration products effectively filled pores with diameters ranging from 0 to 0.2 mm in the high-performance foamed cement, refining its pore structure and thereby enhancing its waterproof performance and dry-wet - wet cycling stability. Compared with those of commercial foamed cement, the setting time of the high-performance foamed cement was 23.48 % shorter, and its compressive strengths at 1 d and 7 d were 245.78 % and 178.62 % greater, respectively. Furthermore, the production cost per cubic meter of the high-performance foamed cement was 107.29 RMB less than that of ordinary cement. In brief, the high-performance foamed cement can be widely used in a variety of engineering applications because of its performance and economic benefits.