An attempt to apply a slag binder with zeolite in mining construction. Durability and hardness

The paper presents comparative results of strength tests on mortars, hardness of pastes and their microscopic observations. The focus was on alkali activated ground granulated blast furnace slag (GGBFS) to which the zeolite was introduced. Zeolite positively affects the rheological properties, densifies the microstructure by reducing its permeability and binds Ca(OH)₂. It causes lower susceptibility of the binder to corrosion, which can be affected by mine mineralized waters or brines flowing from the salt beds. To increase the mechanical properties, polymer scattered reinforcement was used, which does not corrode in contact with saline waters, contrary to steel reinforcement. The paper presents the results of: Bending strength and compression strength of mortar bars made of slag (S2), slag with zeolite (S3), slag with zeolite and polymer fibers (S5); the Vickers indenter tests results of slag pastes of S2 and S3 as well, up to 90 days of hydration. The 90 day compressive strength was 64.0 MPa; 27.7 MPa and 64.7 MPa, and bending strength: 6.4 MPa; 2.9 MPa and 6.0 MPa, respectively for S2, S3, S5. The Vickers indenter test at HV 1 was as follows: On average 27.04 MPa and 36.69 MPa, respectively for S2 and S3. Microstructure observations were carried out in SEM. The obtained results require further research work.