Correlation Between Ultrasonic Pulse Velocity, Porosity and Compressive Strength of Slag-Glass Mortar Activated with Sodium Carbonate

The huge negative impact of the use of Portland cement as a binder in cementitious composites has called for an imminent need to develop a new binder system that can be used for different cementitious composites. The need to develop a new binder system is a result of the huge amount of emissions resulting from the production of Portland cement. For every tonne of Portland cement produced, there is a corresponding amount of carbon dioxide emitted into the environment. A novel type of mortar incorporating slag and glass powder as a binder and activated with sodium carbonate was developed in this study. The porosity and compressive strength of the mortar were investigated and a correlation between these properties and ultrasonic pulse velocity was derived. Results from this study showed that a structural grade mortar can be achieved by using slag and glass powder activated with sodium carbonate as a binder. However, there is a corresponding decrease in the compressive strength with increasing glass powder content in the binder system. Observation of the ultrasonic pulse velocity of the mortar showed that a non-destructive test can be used successfully to assess the properties of the novel mortar.