Micro-aggregate concrete (MAC), characterized by low elastic modulus and low strength, is widely used in scaled models for shaking table tests. In this study, MAC was prepared using coarse sand with a fineness modulus of 3.6 and its mechanical properties, carbonation depth and steel reinforcement bond performance were evaluated. Digital image correlation (DIC) was used to analyze compressive strain and obtain stress–strain curves. Results showed that the mechanical properties initially increased and then decreased with increasing water–cement ratio; optimal strength and deformation performance occurred at a water–cement ratio of 0.50, with compressive strength of 28.23 MPa, splitting tensile strength of 1.73 MPa and elastic modulus of 11 GPa. Under natural conditions, the carbonation depth of MAC with a water–cement ratio of 0.50 reached 11.8 mm after 240 days, and the steel reinforcement pull-out strength reached 9.6 MPa at 120 days, then decreased at 150 days. When conducting experiments, trends in mechanical properties and durability over time should be considered to ensure overall test reliability. The grain silo model cast with MAC reflected the dynamic response and damage evolution of the prototype structure. These results provide guidance for mix design and test time control of MAC in scaled shaking table tests.
Lu et al. (Sun,) studied this question.