Effect of Activator Type, Curing Condition and Calcium Addition on the Strength and Microstructure of Fly Ash-Based Geopolymers

In this study, utilization of coal fly ash with higher loss on ignition (LOI) for geopolymer mortar was investigated. The fly ash with approximately 9% of LOI was compared with Class F fly ash. Relationship between heat curing condition and strength was clarified. As the results, although compressive strength of geopolymer mortar with higher LOI was 30-50% smaller, it was available for geopolymer mortar as an alumina silicate material. The higher temperature and the longer period for initial curing, the higher strength was obtained. In order to decrease drying shrinkage, the higher temperature and the longer period for heat curing were required.

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Influence of Mixture Proportion and Curing Condition on Contribution of Fly Ash to Strength of Concrete

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.302-303.235 ◽

2006 ◽

Vol 302-303 ◽

pp. 235-241 ◽

Cited By ~ 2

Author(s):

F.-R. Wu ◽

Yoshihiro Masuda ◽

S. Nakamura ◽

S. Sato

Keyword(s):

Fly Ash ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Cement Content ◽

Ash Content ◽

K Value ◽

Fly Ash Concrete ◽

Curing Condition ◽

Strength Difference

To investigate the strength efficiency of fly ash in concrete, the contribution of fly ash to strength, k value was calculated with the equation: the strength difference between fly ash concrete and control concrete with no fly ash due to the different fly ash content divides by the strength difference between both control concrete with no fly ash due to the different cement content which equals to the former different fly ash content. The k values were organized with fly ash specific surface area, concrete curing condition and age of specimens. Based on a large number of data collected from several proceedings and journals published in Japan during 1981 to 2003, the influences of fly ash property, mixture proportion and curing condition on k value were investigated. Within the range of study the following observations were made: (1) When fly ash concrete kept in moist curing, the k value of fly ash with specific surface area from 250 to 500 m2/kg is averagely 0.5 to 0.6 or higher at an age of 91 days and later, whereas that of fly ash with specific surface area from 150 to 250 m2/kg is around 0.4 to 0.5, and with some cases contributing little to the strength. (2) In the range of a portland cement content of 250 to 450 kg/m3, the strength contribution tends to increase as the cement content increases. (3) The contributions of fly ash to strength at 91 and 364 days are 1.44 to 1.97 times as large as those at 28 days, respectively, by standard curing, but conversely decrease to 0.75 to 0.79 times those at 28 days by air curing.

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Influence of curing condition on thermo-mechanical properties of fly ash reinforced epoxy composite

Composites Part B Engineering ◽

10.1016/j.compositesb.2019.107301 ◽

2019 ◽

Vol 176 ◽

pp. 107301 ◽

Cited By ~ 3

Author(s):

A. Pattanaik ◽

M. Mukherjee ◽

S.B. Mishra

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Epoxy Composite ◽

Curing Condition

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Experiment on Making Autoclaved Sludge Bricks with the Dewatered Sludge from Water-Supply Plant

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.261-263.829 ◽

2011 ◽

Vol 261-263 ◽

pp. 829-833

Author(s):

Sai Jun Zhou ◽

Jun Tong Qu

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Water Supply ◽

Urban Water ◽

Urban Water Supply ◽

Optimal Parameters ◽

Optimal Process ◽

Curing Conditions ◽

Urgent Task ◽

Curing Condition

How to efficiently dispose of the urban water-supply plant sludge has become an urgent task of controlling pollution caused by municipal solid waste. This paper is an experiment on autoclaved sludge brick, which is mainly made of sludge from the water-supply plants, fly ash, lime, sand and cement, integrated with the manufacturing process of autoclaved fly ash brick. By orthogonal optimal process, we get the optimal parameters for making sludge bricks as follows: W sludge : W ash : W lime = 15%: 45%: 15%, stirring intensity being 1400r/min, forming and curing condition being the constant temperature and humidity Curing Box (60 °C, humidity 95%), and autoclave curing condition being 1.2Mpa (time 10h). With the optimal parameters, the compressive strength of the produced bricks reaches 20.8Mpa, and its flexural strength reaches 5.4 Mpa. Besides, stirring conditions, forming and curing conditions together with the influence of curing conditions on autoclaved sludge bricks’ mechanical properties are discussed.

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