Properties of Cement Compacts Prepared by High-Pressure Compaction

摘要

The purpose of this investigation was to determine the combined effects of fly ash as a partial replacement for portland cement and the use of high-pressure compaction in reducing the porosity and increasing the compressive strength of prepared miniature compacts. According to current practice and theory, for specialized uses, portland cement concrete materials with strengths approaching 20,000 psi (140 MPa) may be produced by reducing the amount of porosity present in the microstructure of the paste-matrix material. To accomplish this, both high-pressure compaction and increased formation of cementitious products form a pozzolanic reaction have provided excellent results. However, judging from an extensive literature survey, the effect of combining the two has not been examined. The three main parameters investigated included the initial compacted porosity level from high-pressure compaction, the percentage fly ash replacement of the cement, and curing duration. Additionally, the effects of accelerated curing by oven-drying was explored. The study revealed that high-pressure compaction, followed by accelerated curing, is an excellent means of producing a low-porosity condition and, thereby, a greater strength in a cementitious material.