Stabilization Characteristics of Clays Using Class C Fly Ash

1998 ◽  
Vol 1611 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Anil Misra
Keyword(s):  
Fly Ash ◽  
Chemical Properties ◽  
Clay Soils ◽  
Statistical Characteristics ◽  
Oxide Content ◽  
Physical And Chemical Properties ◽  
High Calcium ◽  
Class C ◽  
Physical And Chemical ◽  
And Chemical Properties

Coal-burning utilities using subbituminous coal from Wyoming typically produce fly ash, which, because of its high calcium oxide content, may be classified as Class C fly ash. These ashes are characterized by their self-cementing property and therefore can be used for soil improvement. Stabilization characteristics of clay soils blended with Class C fly ash were evaluated. Because fly ash is a by-product, uniformity of its physical and chemical properties is significant for quality control. The statistical characteristics of fly ash physical and chemical properties are obtained and compared with the data in literature. Fly ash is blended with several different clay soils of varying plasticity to study moisture-density relationships and strength behavior of stabilized soils. It is observed that the fly ash used in these experiments has a rapid hydration characteristic. Consequently, higher densities and strengths are achieved when the compaction is performed with little or no delay after the addition of moisture to clay-fly ash blends. Conversely, delayed compaction produces low densities and strength. In addition, it is observed that the stabilization characteristics are closely related to the soil mineral type and plasticity. Results also are presented for strength gain behavior with curing period for the various soil-fly ash blends.

Monitoring of Fluctuations in the Physical and Chemical Properties of a High-Calcium Fly Ash

1987 ◽  
Vol 113 ◽  
Author(s):  
Scott Schlorholtz ◽  
Ken Bergeson ◽  
Turgut Demirel
Keyword(s):  
Fly Ash ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Physical And Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Studies ◽  
High Calcium ◽  
Physical And Chemical ◽  
And Chemical Properties

ABSTRACTThe physical and chemical properties of fly ash produced at Ottumwa Generating Station have been monitored since April, 1985. The fly ash is produced from burning a low sulfur, sub-bituminous coal obtained from the Powder River Basin near Gillette, Wyoming. One-hundred and sixty samples of fly ash were obtained during the two year period. All of the samples were subjected to physical testing as specified by ASTM C 311. About one-hundred of the samples were also subjected to a series of tests designed to monitor the self-cementing properties of the fly ash. Many of the fly ash samples were subjected to x-ray diffraction and fluorescence analysis to define the mineralogical and chemical composition of the bulk fly ash as a function of sampling date. Hydration products in selected hardened fly ash pastes, were studied by x-ray diffraction and scanning electron microscopy. The studies indicated that power plant operating conditions influenced the compressive strength of the fly ash paste specimens. Mineralogical and morphological studies of the fly ash pastes indicated that stratlingite formation occurred in the highstrength specimens, while ettringite was the major hydration product evident in the low-strength specimens.

Influence of Fluidized Fly Ash on the Selected Physical-Mechanical Properties of the Autoclaved Aerated Concrete

2014 ◽  
Vol 899 ◽  
pp. 409-414 ◽  
Author(s):  
Alena Struhárová ◽  
Stanislav Unčík ◽  
Svetozár Balkovic ◽  
Mária Hlavinková
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Amorphous Phases ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete ◽  
Free Cao ◽  
Physical And Chemical ◽  
And Chemical Properties

Fluidized fly ash has different physical and chemical properties compared to fly ash emerging from classic combustion. It contains amorphous phases resulting from a dehydration of clay minerals as well as unreacted sorbent of CaCO3, free CaO and anhydrite (CaSO4). Work targets the possibilities of production of an autoclaved aerated concrete (AAC) from fluidized fly ash, and its influence on particular physical-mechanical properties of autoclaved aerated concrete.

Influence of Physical and Chemical Properties on the Activity of Fly Ashes

1987 ◽  
Vol 113 ◽  
Author(s):  
F. Sybertz
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Hydrochloric Acid ◽  
Potassium Hydroxide ◽  
Chemical Properties ◽  
Experimental Program ◽  
Physical And Chemical Properties ◽  
Fly Ashes ◽  
Physical And Chemical ◽  
And Chemical Properties

ABSTRACTIn an experimental program, the suitability of various methods for testing the pozzolanic activity of fly ash was investigated. The research was conducted on virtually all fly ashes approved as concrete additives in Germany. This paper discusses differences in the particle size distribution and the solubility on dissolution with hydrochloric acid and potassium hydroxide of the fly ashes. It also reports on interrelationships between the physical and chemical properties of the fly ashes and the workability and strength of mortars containing fly ash.

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