Portland clinker is normally used as the main component in cement manufacturing. It is a mix of different oxides and silicates suitable for the production of low cost structural ceramics. In this work, it is used as raw material in making ceramic matrix composites fit for use as structural ceramic. The sinterability of Portland clinker with different oxides (Al₂O₃, MgO and SiO₂) and other ceramic enhancers (CaF₂) is evaluated by dilatometry and density in response to temperature. The manufacturing process includes mixing, followed by cold isostatic pressing at 180 MPa and sintering in air at temperatures between 1100 and 1420°C. At these temperatures the sintering is carried out with liquid phase, demonstrated by optical and scanning electronic microscopy (SEM). There are indications of reactivity between the base material and the additives.