INVESTIGATING THE LINEAR EXPANSION, SET, AND STRENGTH BEHAVIORS OF THE BINARY MIXTURE; PORTLAND CEMENT CLINKER-GYPSUM

The linear expansion, early-age compressive strength and setting times of the binary mixtures of gypsum and portland cement clinkers of relatively low c3a-contents were investigated. for this reason, type 1, 2, and 5 of portland cement-clinkers were selected and a number of binary mixtures were designed. at relatively lower percentages of gypsum (about 5%), the early strength behavior is improved. results obtained for compressive strength of mixtures with 5% gypsum confirm the possibility of achieving 28- and 90-day compressive strengths up to values higher than 100 mpa and 130 mpa, respectively. at relatively higher percentages of gypsum (more than 25%), excessive expansion caused by ettringite formation results in the formation of micro-cracks effectively weakening the strength behavior. the work suggests that type s expansive cements could be produced from portland cement clinkers of relatively low c3a- contents.