HPC Mix Characterization Using X-Ray Diffraction and Electron Microprobe Analyses

Traditionally, concrete mixes are designed by testing a large number of trial mixtures. Compression testing is the most common method of evaluating the performance of concrete mix design. It is well known that the compound composition of the cementitious materials has a direct correlation with the strength of concrete and its development with time. This paper demonstrated that it is feasible to reduce the number of trial mixes necessary to design a high performance concrete mix. Some of the variables involved in the high performance concrete design are related to the proportions of cementitious materials (portland cement, silica fume, and fly ash). A method is presented to select the proportions of cementitious materials for a required strength and time based on cement chemistry. The compound composition of a small amount of several cementitious material mixes is determined using X-Ray Diffraction and Electron Microprobe techniques and can be used for optimization. Mortar cubes prepared using each mixture of cementitious material are tested under uniaxial compression. The results obtained from mortar cube testing are consistent with those obtained from X-Ray Diffraction and Electron Microprobe analyses.