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Pro083

Effect of fly ash gradation on workability, strength and durability of Portland cement fly ash mortars



Author(s): Xianping Liu, Peiming Wang, Jie Sun
Paper category: Conference
Book title: 2nd International conference on Microstructural-related Durability of Cementitious Composites
Editor(s): Guang Ye, K. Van Breugel, Wei Sun, Changwen Miao
Print ISBN: 978-2-35158-129-2
e-ISBN: 978-2-35158-123-0
Publisher: RILEM Publications SARL
Pages: 1452- 1461
Total Pages: 9
Language: English


Abstract: 
Four graded fly ashes were incorporated respectively with Portland cement by 50% (w/w) to investigate the effect of fly ash gradation on the workability, strength and durability of Portland cement fly ash mortars. The results indicated that appropriate gradation of fly ash decreased the void content and increased the flowability of fresh mortar, as well as improved strength and durability of hardened mortar due to the modification of microstructure. Based on the grey correlation theory, the particle size of fly ash under 8.1 μm, especially ranged between 3.9 and 8.1 μm, was beneficial to the increase of compressive strength, impermeability and carbonation resistance, but unfavorable to the decrease of shrinkage of fly ash incorporated mortars. However, the particle size of fly ash above 8.1 μm, especially ranged between 8.1 and 15.7 μm, was on the contrary. With the increase of specific surface area, the pozzolanic activity of fly ash was improved due to more amorphous phase and calcium oxide, which resulted in more non-evaporable water and less calcium hydroxide in hardened cement paste. Fly ash particles with different chemical compositions had different reaction activity, hence played different roles in the microstructure of hardened mortar.


Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00