Very high strength cement pastes prepared by hot pressing and other high pressure techniques

Abstract Very high strengths approaching zero-porosity values have been measured on materials prepared by hot pressing pastes of conventional cements, using pressures of 25, 000–50, 000 psi at temperatures near 150°C. Typical strengths for hot pressed samples are: 73, 900 (compressive); 59, 300; 6320; 11, 820 (compressive, indirect tensile, and shear, all expressed in psi). High pressure specimens prepared at 100, 000 psi without elevated temperatures resulted in strengths of 46, 100; 4020; and 8400 (compressive, indirect tensile, and shear, respectively). The microstructures as revealed by scanning electron microscopy are very dense, and the hot pressed samples, particularly, are dimensionally stable.