A COMPARATIVE STUDY FOR STRENGTH CLASSIFICATION
The importance of providing a system for strength classification is emphasized by the diversity of testing methods, number of representative samples needed, and testing equipment required. In the present work three Egyptian types of rocks: Limestone, Sandstone and Granite with different specimen sizes are used to carry out a comparative study concerning the determination of the compressive strength using uniaxial compression, point-load, and Schmidt hammer techniques. Testing results are statistically analyzed and correlated with some physical properties like porosity, density and sound velocity. * Associate Professor, Mining Department, Faculty of Engineering, Cario University TÜRKİYE X I I I . M A D E N C İ L İ K K O N G R E S İ , 1 9 9 3
Blast design in monumental stone quarries
ABSTRACT Controlled blasting design in situations where blocks of rock are required for finished monumental stone or building blocks has been described in this paper. The basic concepts applicable to blast design have been outlined and various aspects involving drilling of holes, spacing, burden, explosive selection, loading of holes have been discussed. The effect of blasting with relief and without relief on the development of the shear zone has been also considered. The entire design process including blast optimization has been described by an example.
Compressive strength comparison and crystal morphology of dental cements.
Three dental cements were aged as cylindrical specimens in distilled water for periods up to 2 years. Zinc phosphate cement showed no change in compressive strength over the aging time, while glass ionomer and polycarboxylate cements increased in compressive strength. Energy dispersive spectroscopy of the crystalline surface of the zinc phosphate cement samples indicated a wide range of crystalline structures and compositions.