https://www.sydneyconstructionmaterials.com.au/mk_pozzolan.html
Molar ratio
NaAlO2 Solution consisting of 34 wt% NaAlO2, 9 wt% NaOH and 57 wt% water. Supplied by Redox Ltd., Australia
Fumed silica Silica Fume SF 98, Australian Fused Materials PL. 93 wt% silica, 4 wt% (ZrO2+HfO2)
Two sets of OPC samples were made by mixing Aalborg cement with a water/cement ratio of 0.3, one set with 40 wt% sand and the other without. They were cast similar to the GPs (see above). They were cured at ambient for 28 days before testing.
Physical and mechanical properties
The bulk densities of all the materials were determined by measuring the mass and the volume with a Hg pycnometer.Open porosities were determined by immersing each specimen in octane (non-polar liquid) for 24 h and measuring the mass absorbed (density of octane=0.703 g/cm3). Saturation with water was considered unsuitable because of leaching in water, especially Na [11]. This method of determining open porosity is a comparative method and not an absolute determination as the open porosity may be higher because of incomplete permeation of the liquid into the pores.
CCS specimens of 25-mm diameter and 40-mm high, were cast for each batch. Each specimen was ground flat and parallel using silicon carbide paper prior to testing. The CCS tests were conducted at room temperature in a servo-electric universal mechanical testing machine (Instron8562) with a 100 kN load cell. The specimens were tested in position control at a cross head speed of 5 micron/s. A minimum of five specimens for each composition were tested.
Flexure specimens were prepared as bars 6 x 10 x 50 mm, for elastic modulus and strength evaluation. Five specimens were obtained from each batch composition. Young’s modulus of each specimen was measured using a non-destructive impulse excitation technique. The long edges of each specimen were then chamfered on the prospective tensile face to avoid edge failures. The strength or modulus of rupture (MOR) was determined using three-point bending with a support span S=40 mm on the testing machine at a cross-head speed of 5micron/s. The MOR values, sigma F, were calculated from the failure load and the specimen dimensions using the formula[12]:
Observations of fracture surfaces of MOR samples also indicated that large pores were the fracture origin sites.The EDS analyses of the matrices were carried out on all the materials and the values are listed in Table6. The lower the Na/Al ratio, the less Na is available for binding to form a coherent solid. Hence, this is reflected in the strength value of SAGP. The EDS analysis will give a lower Na value because of the migration of Na under the electron beam. Higher Si/Al ratio for LGP is not clear, but possibly all the SiO2

Fig. 4 Backscattered scanning electron micrographs of polished sections of
(a) SAGP, (b) FSGP, (c) LGP and (d) SGP.MK relics are shown in each image and are marked by a narrow and other minor phases are identified where appropriate