Cementitious compositions

A homogeneous uncured cementitious composition which comprises the ingredients:

• a. a hydraulic cement selected from the group consisting of cements which comprise compounds of calcium, aluminum, silicon, oxygen and/or sulfur which set and harden by reaction with water,
• b. water, and
• c. a water-dispersible polymer, wherein
• i. the ratio of water to hydraulic cement is in the range 15 - 28 parts by weight of water to 100 parts by weight of hydraulic cement;
• ii. the ratio of water-dispersible polymer to hydraulic cement is in the range 0.1 - 3.0 parts by weight of water dispersible polymer to 100 parts by weight of hydraulic cement;
• and
• iii. the water-dispersible polymer is selected, with reference to the hydraulic cement and to the selected proportions of polymer and water, for its suitability to facilitate homogenization and to yield on homogenization an uncured composition which can be shaped under pressure and which is shape retaining,
• and wherein the ingredients (a), (b) and (c) have been subjected to a homogenization process of dispersion and homogenization so that they are regularly dispersed throughout the composition;
• such that on curing and drying, the homogeneous uncured composition yields a cured and dried cementitious composition having a modulus of rupture greater than 15 MN/m.sup.2.