Influences of Curing Conditions On Strength and Microstructure of Lime-Amended Fly Ash

Abstract

The influence of curing conditions on strength and microstructure of lime-amended fly ash is presented in this paper. A series of compaction, UCS and CBR tests are carried out by varying the lime content from 0 to 12%. The curing of specimen is done for 0 to 60 days under temperature of 10ºC to 90ºC. The test results showed that an increase of either lime content or curing period increases the UCS and CBR values. The curing temper-ature also influences the rate of strength gain and formation of hydration products. Lower temperature cured specimens showed gradual increase in strength even up to 60 days whereas the specimen cured at higher tem-perature stabilized much earlier. Mineralogical analysis showed new amorphous products of CSH and CASH compounds. The microstructural study indicates formation of greater amount of needle like structure of ettringite which reduces the inter-particle voids and takes a major role in strength enhancement.