Autopore 4 9500 series

The porosity and pore volume characteristics of the pastes were studied by Mercury Intrusion Porosimetry (MIP, Micromeritics’ AutoPore IV 9500 Series, Norcross, GA, USA). Samples for MIP were taken from the fractured compressive strength specimens. Chunks of mortars were crushed to smaller pieces and pore water was removed by the solvent replacement method, with isopropanol as the solvent. The detailed experimental method is covered in [42 (link),48 (link),49 (link),50 (link),51 (link),52 ].

To study the effects of different hydration curing periods on the pore size distribution of CSZ specimens, a mercury intrusion porosimeter (MIP, AUTOPORE IV 9500 series, Micromeritics Instrument Corp, Downers Grove, IL, USA) method was performed. The tested specimens were broken into 3–5 mm pieces and the total weight was approximately 1.5 g. The pieces were dried in a vacuum chamber at 50 °C for 24 h to remove absorbed water in pores.
The microstructure of HSZ and CSZ specimens with different hydration curing time was determined by FEI NOVA Nano-SEM 450 field emission scanning electron microscopy (FE-SEM, FEI company, Chelmsford, MA, USA).

Mesopores and a portion of the macropores of the rice husks, from 1.7 up to 300 nm, were measured by Barrett-Joyner-Halenda (BJH) method. The samples were prepared and analysed as described in the previous section for surface area analysis.
Macropores from 100 nm up to 50,000 nm were characterized by the mercury intrusion porosimetry (MIP) method using a Micromeritics’ AutoPore IV 9500 Series. The samples were dried at 85 °C before the analysis. The porosity was measured using a 5 bulb solid penetrometer of 1 mL, stem volume 0.392 ml, penetrometer constant 10.79 ul/pF and pressure 0–30,000 psia.