Characterization of autoclaved aerated concrete (AAC) samples by SEM, XRD and µ-CT

Autoclaved aerated concrete (AAC) samples from construction and demolition waste. The density class and compressive strenght were tested on small specimen: batch 1: 0.39 g/cm³; 4.9 N/mm² batch 2: 0.59 g/cm³; 4.2 N/mm² batch 3: 0.30 g/cm³; 2.2 N/mm² batch 4: 0.67 g/cm³; 2.9 N/mm² batch 5: 0.45-0.58 g/cm³ batch 6: 0.34-0.57 g/cm³ Scanning electron microscopy (SEM) was performed on a Thermo Scientic Quattro S ESEM and secondary electron images of uncoated fracture surfaces were obtained in high vacuum mode at an acceleration voltage of 2-5 kV. Micro X-ray Computed Tomography (µXCT) was performed on a Bruker Skyscan 1275 µXCT. X-ray diraction measurements were performed on a Malvern-Panalytical Aeris in BraggBrentano geometry with a Cu X-ray source, 0.5° divergence slit, 2.3° Soller slits, Ni Kβ lter and a linear position-sensitive detector (PIXcel1D-Medipix3). Powder samples were back loaded and measured under rotation by continuous scans from 6.6 to 70° 2θ with a step size of 0.01°.