Accession Number : ADA249106


Title :   Processing and Properties of Chemically Derived Calcium Silicate Cements


Descriptive Note : Final rept. 1 Apr 1988-31 Aug 1991


Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK


Personal Author(s) : Scheetz, B. E. ; Mecholsky, J. J. ; Adair, J. H.


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA249106


Report Date : 27 FEB 1992


Pagination or Media Count : 89


Abstract : Chemical engineering approach has been employed to promote elimination of large size flaws and improve strength. A general philosophy in the program was to prepare advanced cements designated as chemically bonded ceramics and use fracture mechanics and fractography to determine the size and origin of the critical flaw. flaws of a certain type were eliminated iii subsequent materials by alteration in some stage of the processing scheme. One of the most important goals of the current program was to analyze the effectiveness of indentation techniques for evaluating the mechanical properties of cementitious materials. The indentation-strength technique was found applicable to MDF cements for measuring fracture toughness. The indentation- strength technique and fracture surface analysis were found applicable MDF cements for measuring fracture toughness. By using both optical and electron microscopes, fractograph becomes a powerful tool to estimate the toughness. Therefore we suggest the small crack techniques are applicable for the measurement of crack growth resistance in cementitious materials as long as the crack size is that a characteristic dimension of the microstructure.


Descriptors :   *CEMENTS , MECHANICAL PROPERTIES , SURFACE ANALYSIS , TOOLS , CRACKS , ELECTRON MICROSCOPES , STRENGTH(GENERAL) , CHEMICAL ENGINEERING , CALCIUM ALLOYS , ALKALINE EARTH METALS , POWDER METALLURGY , TOUGHNESS , FRACTURE(MECHANICS) , FRACTOGRAPHY , CERAMIC MATERIALS , ELECTRONS


Subject Categories : PHYSICAL CHEMISTRY
      CERAMICS, REFRACTORIES AND GLASS
      METALLURGY AND METALLOGRAPHY


Distribution Statement : APPROVED FOR PUBLIC RELEASE