EFFECTS OF AGGREGATE CONTENT ON THE INTERCONNECTED PORE FORMATION AND PROPERTIES OF POROUS PURGING PLUG MATERIALS

The physical properties and microstructure of porous purging plug materials with different aggregate contents and prepared at different firing temperatures were investigated by means of X-ray diffraction, scanning electron microscopy, air permeability, pore size distribution, apparent porosity, bulk density, cold modulus of rupture (CMOR), cold elastic modulus (E) and cold crushing strength (CCS) tests. The results show that the aggregate content had a great effect on the interconnected pore formation and properties of porous purging plug materials. With decreasing aggregate content, the apparent porosity and air permeability increased due to the distance between aggregates increasing and Al(OH)₃ formation, and the pore size distributions changed from a monomodal distribution to a bimodal distribution. The higher temperature facilitated the formation of a denser structure and interconnected pores. In addition, the CCS and porosity were found to follow a simple exponential relationship. When the apparent porosity increased, the CCS decreased, and vice versa