Influence of various hydraulic binders on performance of very low porosity cementitious systems

The influence of various hydraulic binders on the mechanical properties of very low porosity cement-based materials has been investigated. Alkali-activated slag cement and aluminate cement systems are compared with the ordinary Portland cement system. The results demonstrate that the alkali-slag system has the highest compressive strength and aluminate cement intermediate values. Development of structure and properties confirms that very low porosity cement pastes hydrate continuously during 90 days of cure. Regression analysis of the porosity-strength relation described by Schiller's equation indicates that the constants at "zero strength" are much less than those for normal porosity systems. These relations indicate that alkali-slag cement and aluminate cement systems have potentially higher performance characteristics than Portland cement due to their different products. The role of hydration products e.g. crystalline Ca(OH)₂ on mechanical properties is discussed.