Design and characterization of carbonate-stone-powder-based foam concrete

Foam concrete offers a promising solution for high-dosage utilization of solid waste and is valued for its lightweight characteristics and excellent insulation properties. Carbonate stone powder, a byproduct of stone processing, poses an environmental threat due to its high production rates if not properly managed. In this study, foam concrete based on high-dosage carbonate stone powder was prepared using pre-fabricated foam and ambient curing methods. The effects of the carbonate stone powder dosage and foam content on the properties of the foam concrete were investigated. Macroscopic properties such as compressive strength were tested and analyzed. Moreover, the microstructure and crystal structure of the foam concrete were examined using scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. In addition, X-ray computed tomography (XCT) was employed to analyze the pore structure of the foam concrete. It is found that the carbonate stone powder content could reach up to 80 wt%, and the highest strength achieved was 43.00 MPa. The dry density ranged from 386.98 to 1640.34 kg/m3, and the lowest thermal conductivity was 0.1041 W/(m·K). Notably, carbonate stone powder could reduce the average pore diameters of the samples, promoting an improved thermal insulation performance. Considering the key performance parameters, such as compressive strength, dry density, and thermal conductivity, the carbonate-stone-powder-based foam concrete can fulfill engineering specifications and has substantial potential for recycling solid waste carbonate stone powder.