Performance of a Fly Ash Stabilized Pavement

1989 ◽  
Vol 178 ◽  
Author(s):  
Joakim G. Laguros ◽  
Curt Hayes
Keyword(s):  
Fly Ash ◽  
Concrete Surface ◽  
Asphaltic Concrete ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Calcium ◽  
Field Samples ◽  
High Calcium Fly Ash ◽  
Term Basis

AbstractAn expansive shale roadbase, stabilized with a Class C (high-calcium) fly ash received an 11–inch full–depth asphaltic concrete surface layer and the highway was opened to traffic six years ago. Periodic sampling and visual observations indicate that the performance of the pavement test sections are above average.Analyses of field samples showed that fly ash was effective in ameliorating the texture and plasticity of the shale and imparting strength to it on a long term basis. Pavement deflections and the extent of cracking have not increased beyond acceptable levels during the six year period.X-ray diffraction studies show a reduction of the areas under the peaks and the SEM observations reveal a dense degree of packing and reduction of the void areas. These modifications occur during the first two years of service and any changes beyond that period appear to be minor.

Fly Ash in Shale Stabilization for Highway Construction

1985 ◽  
Vol 65 ◽  
Author(s):  
M. Saleh ◽  
Joakim G. Laguros
Keyword(s):  
Fly Ash ◽  
Substantial Reduction ◽  
Aluminum Silicate ◽  
X Ray Diffraction ◽  
Clay Particles ◽  
Angle Of Internal Friction ◽  
High Calcium ◽  
Field Samples ◽  
High Calcium Fly Ash ◽  
Experimental Project

ABSTRACTThe expansive shales used for roadbeds in Oklahoma are traditionally stabilized with lime. Stabilization with a Class C (high-calcium) fly ash was explored and compared to an optimum design utilizing the conjunctive use of fly ash, lime and cement, in the laboratory and in a field experimental project. Periodic visual observations indicated that the performance of test sections was excellent. Analyses of field samples showed that fly ash, either alone or mixed with lime and cement, was effective in ameliorating the texture and plasticity of the shale by reducing the amount of clay size particles and by imparting higher strength levels to the shale. Laboratory samples showed better stabilization than field samples, but the field samples performed at an acceptable level in measurements of compressive and beam strength, cohesion, angle of internal friction and resistance to deflection. The microstructure of stabilized shale was studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Nonbasal (hkl) reflections in stabilized oriented specimens suggest that the clay particles acquire high resistance to dispersive forces. The reduction of the areas under the peaks help explain the strength gain observed. The SEM observations indicated newly formed hydration products, possibly calcium aluminum silicate hydrate crystals, and a rather dense degree of packing as manifested by the substantial reduction of void areas as a result of stabilization.

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.

X-ray Diffraction Analysis of Fly Ash. II. Results

1990 ◽  
Vol 34 ◽  
pp. 387-394 ◽  
Author(s):  
G. J. McCarthy ◽  
J. K. Solem
Keyword(s):  
Fly Ash ◽  
Diffraction Analysis ◽  
Chemical Constituents ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Power Station ◽  
Crystalline Phases ◽  
X Ray ◽  
High Calcium

AbstractA protocol for semi-quantitative XRD analysis of fly ash has been applied to 178 ashes in studies of the typical mineralogy of high-calcium and iow-calcium fly ash, the consistency of fly ash mineralogy from a typical power station, the partitioning of chemical constituents into crystalline phases, and the crystalline phases relevant to the use of fly ash in concrete.

scholarly journals Beneficial utilization of recycled asphaltic concrete aggregate in high calcium fly ash geopolymer concrete

2021 ◽  
pp. e00615
Author(s):  
Athika Wongkvanklom ◽  
Patcharapol Posi ◽  
Apichit Kampala ◽  
Traitot Kaewngao ◽  
Prinya Chindaprasirt
Keyword(s):  
Fly Ash ◽  
Concrete Aggregate ◽  
Geopolymer Concrete ◽  
Asphaltic Concrete ◽  
High Calcium ◽  
High Calcium Fly Ash

Test Research on Preparation of New Wall Material with Iron Tailings in Tangshan Area

2011 ◽  
Vol 295-297 ◽  
pp. 535-538
Author(s):  
De Qing Gan ◽  
Chao Chen ◽  
Jin Xia Zhang
Keyword(s):  
Compressive Strength ◽  
Electron Microscope ◽  
Fly Ash ◽  
Wall Material ◽  
X Ray Diffraction ◽  
Steam Curing ◽  
X Ray ◽  
A New Technique ◽  
Scanning Electron

This paper discussed the experimental resuhs of exploiting brick materials with iron tailing materials in Tanshang area. Through preparation of iron tailing bricks, the technical flow and production proportion was obtained. The results show that a burning-and steam curing-free brick product with a compressive strength of 28.30 MPa and Flexural strength of 5.63 MPa as the following: iron tailing; fly ash; sand; CaO; gypsum; cement. And long-term properties of a burning-and steam curing-flee brick is also studied by experiments in this paper. Put forward a new technique of making materials with iron tailing. At the same time, the micro mechanism of iron tailing brick was also studied with X-Ray Diffraction (XRD) and Scanning Electron Microscope(SEM).

scholarly journals Effects of Temperature in Different Initial Duration Time for Soft Clay Stabilized by Fly Ash Based Geopolymer

2018 ◽  
Vol 4 (9) ◽  
pp. 2082 ◽  
Author(s):  
Abdalla Mohammed Shihab ◽  
Jasim M Abbas ◽  
Amer M Ibrahim
Keyword(s):  
Fly Ash ◽  
Low Cost ◽  
Soft Clay ◽  
Volumetric Strain ◽  
Curing Temperature ◽  
X Ray Diffraction ◽  
Duration Time ◽  
High Calcium ◽  
High Calcium Fly Ash ◽  
Edx Analyses

When soft clay soils are included in engineering projects, it’s stabilized usually with some kinds of admixtures named as stabilizers. The common stabilizers that highly practiced are OPC, lime, high calcium fly ash (FA), etc. Each one of these stabilizers has its shortcomings. Geopolymers are the product of alkali activated aluminosilicate sources that excelled as an alternative to ordinary binders due to its sustainability, low cost and good mechanical properties. This study investigates the effects of some key elements like liquid over fly ash ratio (Liq/FA), initial duration curing time (D) and its temperature to soil – FA based Geopolymers samples characterized by its unconfined compressive strength testing (UCS), volumetric measurements, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-Ray diffraction (XRD). The Liq/FA taken as 2.71, 3.167, 3.8 and 4.75 respectively and the duration time taken were 1, 6, 18 and 24 hrs. respectively. The tests results showed that the maximum peak strength gain when Liq/FA is 3.8 at 90 oC with 24 hrs. D. It was observed that Young’s Modulus increased with increasing curing temperature for certain D. Volumetric strain increased by increasing D and its temperature. SEM and XRD analyses confirmed the Geopolymers gels formation for a selective precursor while EDX analyses showed that silicon over aluminium ratio is 1.38 for selective spectrum within the gel to the same mixture. 

Geopolymer Synthesis Using Metakaolin and High Calcium Fly Ash as Binary System Geopolymer

2020 ◽  
Vol 1007 ◽  
pp. 65-70
Author(s):  
Thammaros Pantongsuk ◽  
Chayanee Tippayasam ◽  
Pakamon Kittisayarm ◽  
Siripan Nilpairach ◽  
Duangrudee Chaysuwan
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Construction Material ◽  
Construction Materials ◽  
Chemical Properties ◽  
Waste Products ◽  
X Ray ◽  
Alternative Construction ◽  
High Calcium ◽  
High Calcium Fly Ash

Conventional cement production process emits tons of carbon dioxide gas which is one of the greenhouse gases that influence the environment across the world. Discovering the alternative construction material with the eco-friendly process and the performance similar to or greater than ordinary Portland cement has been attractive to find out. This research presented green construction materials or so-called geopolymers from metakaolin substituted by high calcium fly ash by 20, 40, 60, 80 and 100 wt%. Some researches reported that geopolymer produced from metakaolin and fly ash with alkali solution gave a great result, but usually, they used fly ash containing very low calcium component. Compressive strength at 3, 7 and 28 curing days and flowability were conducted. The compressive strength of geopolymers blended with high calcium fly ash was still developed as the curing day increased and revealed the highest at 28 days especially on MK40 (high calcium fly ash 60 wt%). Geopolymer pastes prepared with a higher amount of high calcium fly ash exhibited less viscous. It was proved that the high amount of high calcium fly ash could be applied and gave extraordinary compressive strength. Furthermore, X-ray diffraction and X-ray fluorescence were used to investigate chemical properties as well as microstructure by a scanning electron microscope. For phase analysis, the existence of oxides of calcium and sulfur in high calcium fly ash resulted in the formation of thenardite, calcite, portlandite and C-S-H phase associating with geopolymeric phase. Therefore, this research proposed the opportunity for geopolymer production by using abundant high calcium fly ash to raise the value of the industrial waste products and green alternative construction material compared with OPC.

Rietveld quantitative X-ray diffraction analysis of NIST fly ash standard reference materials

2000 ◽  
Vol 15 (3) ◽  
pp. 163-172 ◽  
Author(s):  
Ryan S. Winburn ◽  
Dean G. Grier ◽  
Gregory J. McCarthy ◽  
Renee B. Peterson
Keyword(s):  
Fly Ash ◽  
Diffraction Analysis ◽  
Reference Materials ◽  
Internal Standard ◽  
Standard Reference Materials ◽  
Ratio Method ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray ◽  
High Calcium

Rietveld quantitative X-ray diffraction analysis of the fly ash Standard Reference Materials (SRMs) issued by the National Institute of Standards and Technologies was performed. A rutile (TiO2) internal standard was used to enable quantitation of the glass content, which ranged from 65% to 78% by weight. TheGSASRietveld code was employed. Precision was obtained by performing six replicates of an analysis, and accuracy was estimated using mixtures of fly ash crystalline phases and an amorphous phase. The three low-calcium (ASTM Class F) fly ashes (SRM 1633b, 2689 and 2690) contained four crystalline phases: quartz, mullite, hematite, and magnetite. SRM 1633b also contained a detectable level of gypsum, which is not common for this type of fly ash. The high-calcium (ASTM Class C) fly ash, SRM 2691, had eleven crystalline phases and presented a challenge for the version ofGSASemployed, which permits refinement of only nine crystalline phases. A method of analyzing different groups of nine phases and averaging the results was developed, and tested satisfactorily with an eleven-phase simulated fly ash. The results were compared to reference intensity ratio method semiquantitative analyses reported for most of these SRMs a decade ago.

Sign in / Sign up

Export Citation Format

Share Document