Enhancement mechanism of new type autoclaved calcium carbide residue shell-aggregate on concrete

Enhancement mechanism of new type autoclaved shell-aggregate on concrete was studied by the experiment, using the X-ray diffraction, scanning electron microscopy, and the homogenization analysis methods. The experimental results indicate that effective elastic modulus of shell-aggregate match with the elastic modulus of the mortar matrix, which can explain the enhancement effect of shell-aggregate on mortar matrix. Homogenization method can reflect the actual contribution degree of autoclaved aggregate on concrete performance ideally. Errors between the calculated value and the measured value are only 5%, 6.7%, and 5.8% when the volume fractions of aggregate are 16%, 32%, and 44%, respectively. High strength of autoclaved shell-aggregate concrete is due to a combined action of matched elastic modulus between autoclaved shell-aggregate and mortar matrix, active gradient interface structure between shell-aggregate and mortar matrix, and small deviatoric tensor of stress between shell-aggregate and mortar matrix. (C) 2016 Elsevier Ltd. All rights reserved.