CIVILEN 3510 Lecture Notes - Lecture 3: Modulus Guitars, Tobermorite, Portland Cement
2 May 2016
School
Department
Course
Professor
Document Summary
Basic characteristics of portland cements: chemical composition. C2s: final strength (greater resistance due to chemical attack and a smaller drying shrinkage: most stable, 70% to 80% of the cement, and contribute most to the physical properties. C3a: extremely exothermic, least stable, proportion > 10%, concrete susceptible to surface attack. C4af: less important than other compounds, rate of reaction: medium: other characteristics. Relates to the size of the cement particles. Greater the surface area of a given volume the greater the hydration. Portland cement + h2o c-s-h + c-h + heat. C3s: 2c3s + 6h c3s2h3 (gel) + 3ch + heat. C2s: 2c2s + 4h c3s2h3 + ch + heat. C3a: c3a + 6h c3ah6 + heat. C3s2h gel, hydration product, or tobermorite which is a cementing property. Ch does not have (nor negligible) cementing property. Converting c-h to c-s-h: one method is to add pozzolanic material to the concrete mix (this includes micro-silica and fly ash)
