Accession Number : ADA189691

Title :   Submicroscopic Deformation in Cement Paste and Mortar at High Load Rates.

Descriptive Note : Final rept. 1 Aug 86-31 Jul 87,

Corporate Author : KANSAS UNIV LAWRENCE DEPT OF CIVIL ENGINEERING

Personal Author(s) : Darwin, David

PDF Url : ADA189691

Report Date : 23 Oct 1987

Pagination or Media Count : 15

Abstract : Research into the submicroscopic behavior of the cement paste and mortar constituents of concrete is enhanced through the acquisition of an integrated scanning electron microscope, energy dispersive spectrometer, image analysis system. The combined system is used to obtain crack surveys of cement paste and mortar loaded in uniaxial compression at strain rates ranging from 0.3 to 300,000 microstrain per second. Research background, equipment selection procedures, equipment capabilities, installation, and on-site evaluation are described. Crack dimensions, orientations, and locations are determined using the combined instrumentation. The surface crack distributions are converted to three-dimensional crack distributions, which are in turn used in estimate the portion of the total deformation due to cracking. The new instrumentation provides a major improvement in both the quality and the quantity of crack data available for analysis. Keywords: Cement, Concrete, Electron microscopes, Image analysis, Microcracks, Microscopic, Mortar, Strain rate, Submicrocracks, X ray analysis.

Descriptors :   *CEMENTS, *CONCRETE, ACQUISITION, BEHAVIOR, COMPRESSION, DEFORMATION, ELECTRON MICROSCOPES, ELECTRONIC SCANNERS, IMAGE PROCESSING, MICROCRACKING, MORTARS, SPATIAL DISTRIBUTION, SPECTROMETERS, STRAIN RATE, TEST AND EVALUATION, THREE DIMENSIONAL, X RAYS, MATHEMATICAL PREDICTION, PHASE TRANSFORMATIONS, FAILURE(MECHANICS)

Subject Categories : Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE