Sulphate resisting and high alumina cements as rapid setting composite

Blends made from sulphate resisting Laid high alumina cements as rapid setting composites were studied from the physicomechanical and chemical properties of the cement pastes up to 90 days. The results indicated that the addition of alumina cement up to 20\% increases the water of consistency and accelerates the initial and final setting time. Also, the alumina cement enhances the hydration of cement as measured from the combined water contents. On the other side, the free lime content decreases due to its reaction with the alumina cement during hydration. The bulk density increases and total porosity decreases with curing time and alumina cement. Whereas the compressive strength increases up to 10\% then decreases at 15 and 20\% alumina cement. This is mainly attributed to the type of hydrates formed at each Value of alumina cement.