A Study on the Properties of Blended Recycled Micro Powder Concrete and Insulation Boards Produced via Microbial Foaming

Promoting construction waste utilization, this study explores using 30% mass fraction recycled micro powder (brick/concrete/hybrid) to replace cement in A03 foam concrete, as well as microbial foaming agents for insulation boards. The results show that hybrid micro powder foam concrete achieved higher compressive strength (0.7 MPa, 0.65 MPa) than pure brick (0.54 MPa) and concrete powder (0.61 MPa). For 30% hybrid micro powder insulation boards (brick:concrete ratios 2:8–8:2), when the ratio is 4:6, their performance meets JC/T 2200-2013 standards. At this point, the compressive strength is 0.43 MPa, the drying shrinkage is 0.29 mm, and the thermal conductivity 0.062 is W/(m·K). As the proportion of recycled brick powder increases, the material properties first improve and then decline, indicating that the proportion of recycled brick powder has a significant impact on the material’s overall performance; within an appropriate range, optimal performance can be achieved.