The Influence of Curing Temperature and Curing Period on Strength Development in High Volume Fly Ash Concrete.

Author(s): G. V. P. Bhagath Singh and Kolluru V.L. Subramaniam
Paper category: Proceedings
Book title: Proceeding of the 71st RILEM Annual Week & ICACMS 2017
Editor(s): Manu Santhanam, Ravindra Gettu, Radhakrishna G. Pillai, Sunitha K. Nayar
ISBN:978-2-35158-195-7, 978-2-35158-190-2 (Set)
e-ISBN: 978-2-35158-191-9
Publisher: RILEM Publications SARL
Publication year: 2017
Pages: 39-46
Total Pages: 8
Language : English

Abstract: The strength gain behavior of high volume fly ash concrete is investigated for different curing time intervals at two different curing temperatures (25°C and 40°C). Three different curing intervals 1, 3 and 7 days were used. Samples cured at 40°C showed significantly more rapid strength gain in the first few days and the ultimate compressive strength is attained earlier for 40°C. Extended curing at 40°C however impacts the ultimate strength attained. Curing time of 3 days at 40°C provides sufficient early strength gain while ensuring high ultimate strength. The influence of the temperature regimes on the dissolution of the fly ash glassy phase and formation of reaction products is evaluated using the XRD based direct decomposition technique. Increasing the temperature increases the dissolved glassy content in fly ash. At 40°C, the reacted glassy content increases with an increase in the curing time from 1 day to 7 days. The results of the study clearly establish that the temperature sensitivity of the rate of strength gain exhibited by fly ash mix is due to increased rate of dissolution of glassy phase in fly ash at higher temperatures.