scholarly journals Feasibility of using pozzolanicity tests to assess reactivity of wood biomass fly ashes

2021 ◽  
Vol 72 (12) ◽  
pp. 1145-1153
Keyword(s):  
Electrical Conductivity ◽  
Activity Index ◽  
Pozzolanic Activity ◽  
Material Strength ◽  
Wood Biomass ◽  
Fly Ashes ◽  
Pozzolanic Reactivity ◽  
Pozzolanic Material

Pozzolanic activity of materials can initially be assumed from the quantity of the pozzolanic oxides SiO2, Al2O3 and Fe2O3. Some of the methods for assessing pozzolanic reactivity of materials include measurement of CaO consumption (Frattini test), decrease in electrical conductivity and pH of a solution containing pozzolanic material, or measurement of an increase in strength of mortar with replacement of cement by pozzolanic material (strength activity index, SAI). The above-mentioned pozzolanicity tests are used in this study to evaluate reactivity of wood biomass fly ashes (WBA-F). The results presented in the paper show that only the SAI method can fully reveal the hydraulic and pozzolanic activity of WBA-F.

Multivariate Statistical Analysis of the Wfarddc North American Fly Ash Database

1991 ◽  
Vol 245 ◽  
Author(s):  
Hans S. Pietersen ◽  
Simon P. Vriend ◽  
Gregory J. Mccarthy
Keyword(s):  
Compressive Strength ◽  
Statistical Analysis ◽  
Specific Gravity ◽  
North American ◽  
Activity Index ◽  
Pozzolanic Activity ◽  
Mineral Admixtures ◽  
Fly Ashes ◽  
Glass Chemistry ◽  
Bulk Chemistry

ABSTRACTThe database of chemical, mineralogical and physical characteristics of North American Fly ashes, assembled by the WFARDDC in North Dakota, was analyzed using multivariate statistics. Prior to the multivariate analysis, the data were rearranged in subgroups containing information on bulk-chemistry, glass chemistry, mineralogy and ASTM physical test results. These groups were analyzed individually. The multivariate technique used was Fuzzy C-Means Cluster Analysis, combined with Non-Linear Mapping. Analysis of the data-set indicates a relation between glass network former and network modifier content. The database shows that a subdivision on the basis of bulk CaO (< 11%; 11–20%; >20%) correlates well with the ASTM C618 Σ(SiO2 +Al2O3 +Fe2O3) and/or specific gravity. Mineralogical data indicate a subdivision into clusters containing varying amounts of mullite, quartz and/or ferrite spinel and a variety of Ca-containing minerals; high CaO ashes usually have high Ca-mineral contents. Of the CaO containing minerals, only portlandite contributed slightly to the compressive strength as defined by ASTM C618. Analysis of glass chemistry reveals smaller differences in absolute amounts of major oxides than would be expected on the basis of bulk chemistry alone. Surprisingly, the total glass content does not contribute significantly to 28 day compressive strength; multiple regression analysis only indicates a significant relation of particle size and specific gravity with the ASTM Pozzolanic Activity Index (portland cement). The Pozzolanic Activity Index with lime seems to be of limited importance in evaluating the performance of fly ashes as mineral admixtures in concrete. On the basis of the statistical analysis, suggestions for selection of important classifying variables are made.

scholarly journals Investigations on the Pozzolanic Effect of Sugar Cane Bagasse Ashes Used in Cementitious Composites

2016 ◽  
Vol 10 (1) ◽  
pp. 395-405
Author(s):  
Paula G. Lamezon de Pádua ◽  
Túlio H. Panzera ◽  
Roberto B. Figueiredo ◽  
A. M. Gomes ◽  
Maria T. Paulino Aguilar
Keyword(s):  
Electrical Conductivity ◽  
Differential Scanning Calorimetry ◽  
Sugar Cane ◽  
Activity Index ◽  
Pozzolanic Activity ◽  
Degree Of Crystallinity ◽  
Cementitious Composites ◽  
Chemical Compositions ◽  
Scanning Calorimetry ◽  
Lime Solution

Brazil is a major producer of alcohol from sugar cane, a fuel with low environmental impact. The production of alcohol generates a large amount of bagasse, the biggest waste of Brazilian agriculture. This bagasse is usually burned for energy production providing nearly 3% of residual ashes. The potential use of these ashes like mineral admixture of cementitious composites depends on calcination conditions. The present work identifies the physical and chemical characteristics of ashes from the furnace exhauster, obtained in an industry located at southeast region of Brazil. The ashes were obtained from bagasse of sugar cane harvest in two different seasons. Chemical composition analysis, X-ray diffraction, grain size distribution, loss on ignition, thermogravimetry analysis (TGA), differential scanning calorimetry (DSC), specific surface measurements (BET) and Fourier transform infrared spectroscopy (FTIR) tests were used to characterize the ashes. The pozzolanic activity was estimated by pozzolanic activity index tests with cement and lime, by the modified Chapelle test, electrical conductivity in lime solution tests, TGA and FTIR. The ashes presented different chemical compositions and degree of amorphicity. The ashes with a higher content of silica, the lower organic material content and high degree of crystallinity (1st harvest), for the same size, have higher pozzolanic on electrical conductivity in lime solution tests than the ashes with lower silica content and higher amorphicity (2nd harvest). However, the results of differential scanning calorimetry (DSC) and modified Chapelle method would indicate the pozzolanicity of the ashes of the 2nd harvest. The results of pozzolanic activity index (with cement or lime) indicated the ashes were not pozzolanic.

scholarly journals Quantitative Comparison of Binary Mix of Agro-Industrial Pozzolanic Additions for Elaborating Ternary Cements: Kinetic Parameters

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2944
Author(s):  
Ernesto Villar-Cociña ◽  
Moisés Frías ◽  
Holmer Savastano ◽  
Loic Rodier ◽  
María Isabel Sánchez de Rojas ◽  
...  
Keyword(s):  
Kinetic Parameters ◽  
Sugar Cane ◽  
Research Work ◽  
Pozzolanic Reaction ◽  
Reaction Rate Constant ◽  
Pozzolanic Activity ◽  
Binary Blend ◽  
Activation Free Energy ◽  
Pozzolanic Reactivity ◽  
Bamboo Leaf Ash

In this research work, the quantitative characterization of a binary blend comprised of two pozzolans (sugar cane straw (SCSA)–sugar cane bagasse ashes (SCBA), bamboo leaf ash (BLAsh)–SCBA and paper sludge (PS)–fly ash (FA)) taking into account the calculated values of the kinetic parameters of the reaction in the pozzolan/calcium hydroxide system is shown. The paper shows the most significant and important results obtained by the authors in the quantitative assessment (calculation of kinetic parameters) of the pozzolanic reaction of different mixtures of pozzolanic materials that are residues from agriculture or industrial processes. This allows a direct and rigorous comparison of the pozzolanic activity of the binary combinations of materials. The values of the kinetic parameters (reaction rate constant or activation free energy) constitute a very precise quantitative index of the pozzolanic activity of the binary combinations of materials, which is very useful for its employment in the elaboration of ternary cements. This paper shows that the binary blends 1SCBA60Blash40, 1SCBA50Blash50, 1SCBA70Blash30 have a very high pozzolanic reactivity followed by PSLSFA, 2SCBA50SCSA50, PSISFA and SCWI.

The Effect of Substituting Rdf on the Physical and Environmental Properties of Coal Fly Ash

1988 ◽  
Vol 136 ◽  
Author(s):  
Ashaari B. Mohamad ◽  
David L. Gress
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Physical Properties ◽  
Activity Index ◽  
Coal Fly Ash ◽  
Pozzolanic Activity ◽  
Portland Cement Concrete ◽  
Fly Ash Concrete ◽  
Refuse Derived Fuel ◽  
Cadmium And Lead

ABSTRACTRefuse-derived-fuel (RDF) consisting mainly of waste paper and plastics is a viable fuel source for the production of power. An experimental test burn partially substituting coal with RDF was undertaken by the Public Service of New Hampshire at the Merrimack Power Station.Five percent and ten percent RDF were substituted, on a BTU basis, for coal in the test bums. The chemical and physical properties of the resulting fly ash were determined. Twelve test burn days were run with 4 days of 5% RDF and 8 days of 10% RDF. Emphasis was placed on investigating the effect of the RDF fly ash on Portland cement concrete.Most of the chemical and physical properties of the coal-RDF fly ash were found to be comparable with ordinary coal fly ash except for the amount of cadmium and lead, the pozzolanic activity index and the compressive strength of fly ash concrete. Cadmium and lead were at average levels of 5.1 ppm and 102.6 ppm for the 5% RDF, and 7.8 ppm and 198.3 ppm for the 10% RDF, respectively. Although the pozzolanic activity index of coal-RDF fly ash increases over normal coal fly ash, preliminary results show that the 28-day compressive strength of concrete with direct replacement of cement and sand decreases by up to 30%. Leaching tests on crushed concrete were conducted to evaluate the environmental effect of acid rain.

scholarly journals Evaluating the Effect of Calcination and Grinding of Corn Stalk Ash on Pozzolanic Potential for Sustainable Cement-Based Materials

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Shazim Ali Memon ◽  
Saba Khan ◽  
Israr Wahid ◽  
Yekaterina Shestakova ◽  
Muhammad Ashraf
Keyword(s):  
Activity Index ◽  
Pozzolanic Activity ◽  
Second Phase ◽  
Corn Stalk ◽  
Cement Concrete ◽  
Carbon Particles ◽  
Cement Based Materials ◽  
Two Phases ◽  
Pozzolanic Properties ◽  
Ash Disposal

In developing countries, one of the usual practices is the uncontrolled, open burning of corn stalk (CS) or its utilization as a fuel. It is known that the ash obtained under uncontrolled burning conditions constitutes blackish and unburnt carbon particles as well as whitish and grayish particles (representing crystallization of silica) due to over burning. However, controlling the burning process can improve the quality of ash produced to effectively use it in cement-based materials. Hence, this research was aimed at exploring the pozzolanic properties of corn stalk ash upon calcination and grinding, for it to be used in the manufacturing of sustainable cement-based materials. In order to obtain a suitable corn stalk ash (CSA), which can be used in cement/concrete, a research investigation consisted of two phases. In the first phase, calcination was carried out at 400°C, 500°C, 600°C, 700°C, and 800°C for 2 hours. The tests applied on the resulting ashes were weight loss, XRD, pozzolanic activity index (PAI), Chapelle, Fratini, and consistency. From XRD spectra, it was found that, at lower temperatures, silica remained amorphous, while it crystallized at higher temperature. Ash combusted at a temperature of 500°C possessed largest pozzolanic activity of 96.8%, had a Fratini CaO reduction of 93.2%, and Chapelle activity of 856.3 mg/g. Thus, 500°C was chosen as an optimum calcination temperature. In the second phase, the ash produced at 500°C was grinded for durations of 30, 60, 120, and 240 minutes to ascertain the optimum grinding times. Resulting ashes were examined for hydrometer analysis, Blaine fineness, Chapelle activity, and pozzolanic activity. Experiment outcomes revealed a direct relationship between values of Blaine fineness, surface area, Chapelle activity, PAI, and grinding duration. It was concluded that CSA can be used as a pozzolan, and thus, its utilization in cement/concrete would solve ash disposal problems and aid in production of eco-friendly cement/concrete.

Some Physical, Chemical and Mineralogical Properties of Some Canadian Fly Ashes

1986 ◽  
Vol 86 ◽  
Author(s):  
R. C. Joshi ◽  
B. K. Marsh
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Chemical Properties ◽  
Water Soluble ◽  
Pozzolanic Activity ◽  
Unburned Carbon ◽  
Magnetic Fraction ◽  
Fly Ashes ◽  
Physical And Chemical

ABSTRACTThis paper gives physical and chemical properties of some Canadian fly ashes. Specific surface area, magnetic fraction, water soluble fraction and fraction finer than 45 μm were determined as part of the physical tests. Thermo-gravimetric analyses (TGA) in oxygen and nitrogen were conducted on raw ash samples. The change of pH with time in suspensions of the different ashes in water was also determined. Pozzolanic activity of the ashes with lime for all the ashes was evaluated to measure ash reactivity.The ash activity seems to be related to fineness of the ash measured by the Blaine air permeability method, but not to the fineness measured by nitrogen sorption. Generally the greater the specific surface area, the higher the reactivity of the ash. The correlation was, however, not strong and no other physical or chemical parameter measured in this investigation seems to be related to pozzolanic activity.The results of pH and TGA tests indicated that the ashes differ in many respects from each other. The TGA data suggest that loss on-ignition in many of the ashes is not entirely due to the presence of unburned carbon. Specific surface area determined by various methods seems to provide different values. No characterization parameter was found that was uniquely related to coal type.

Engineering behaviour of a low carbon, pozzolanic fly ash and its potential as a construction fill

1991 ◽  
Vol 28 (4) ◽  
pp. 542-555 ◽  
Author(s):  
B. Indraratna ◽  
P. Nutalaya ◽  
K. S. Koo ◽  
N. Kuganenthira
Keyword(s):  
Fly Ash ◽  
Pozzolanic Activity ◽  
Unburned Carbon ◽  
Low Carbon ◽  
Collapse Potential ◽  
Pozzolanic Reactivity ◽  
Wide Range ◽  
Good Potential ◽  
Class C ◽  
Mae Moh

Detailed laboratory investigations were conducted on Mae Moh fly ash from northern Thailand for the determination of its grain size distribution, mineralogy, pozzolanic activity, compaction and strength characteristics, and the collapse potential. On the basis of the experimental results, this fly ash is classified as ASTM class C, which is considered to be pozzolanic. It has good potential to be utilized as an effective fill for embankments (roads and dams), airfields, pavements, and building bricks, as well as for the stabilization of compressible or erodible foundations. Because of the fact that Mae Moh fly ash contains only a negligible amount of unburned carbon, its pozzolanic reactivity is accelerated, in comparison with the relatively inert, high-carbon fly ash produced elsewhere in Thailand and many other parts of Asia. It is also demonstrated that Mae Moh fly ash can be easily compacted to produce acceptable dry densities over a wide range of water contents. Curing with an adequate moisture supply in the presence of calcium oxide plays an important role in accelerating the pozzolanic reactions, hence improving the time-dependent-properties. This study further proposes that a curing period of 2–3 weeks is sufficient for this material to approach its maximum strength. Although the behaviour of one specific fly ash cannot generalize the wide array of other ashes, the test results obtained for Mae Moh fly ash may be applied to lignite ashes in the category of ASTM class C. Key words: fly ash, structural fill, compaction, compressive strength, shear strength, collapse potential, pozzolanic activity.

Determining Residual Ammonia in Flue Gas Conditioned Fly Ashes and Its Influence on the Pozzolanic Activity

2011 ◽  
Vol 39 (1) ◽  
pp. 103001
Author(s):  
M. R. Mitchell ◽  
R. E. Link ◽  
S. Shanthakumar ◽  
D. N. Singh ◽  
R. C. Phadke
Keyword(s):  
Flue Gas ◽  
Pozzolanic Activity ◽  
Fly Ashes

scholarly journals Phase and Microstructural Characterization of Lime-MK Blended Mixes

2012 ◽  
Vol 730-732 ◽  
pp. 135-140 ◽  
Author(s):  
André Gameiro ◽  
António Santos Silva ◽  
R. Veiga ◽  
Ana Velosa
Keyword(s):  
Microstructural Characterization ◽  
Pozzolanic Reaction ◽  
Material Degradation ◽  
Molar Ratios ◽  
Pozzolanic Reactivity ◽  
Pozzolanic Material ◽  
Granulated Blast Furnace Slag ◽  
Calcium Silicate Hydrates

Metakaolin (MK) is nowadays a well-known pozzolanic material used in cement-based materials. Its benefits are related to its great pozzolanic reactivity when compared with some others pozzolanic materials, like fly ash or ground-granulated blast furnace slag. When MK reacts with calcium hydroxide, cementitious products are formed. It is known that the main phases produced during its pozzolanic reaction at ambient temperature are calcium silicate hydrates (CSH), stratlingite (C2ASH8) and calcium aluminate hydrate (C4AH13). However, in literature there are several discrepancies regarding these phases stability, namely the transformation of stratlingite and C4AH13 into hydrogarnet (C3AH6) at long term. The consequences of that instability are a reduction in the porosity and a loss of microstructural strength that can induce a complete material degradation. The MK is a material with great potential in Portugal, since there is a large abundance of kaolinitic clays, however its development is not yet achieved. In order to answer this demand a research project was initiated with the aim of optimizing the production of MK in Portugal and enhancing the durability of aerial calcitic lime mortars, to be mainly used in conservation and restoration of historical buildings. With the objective of studying the compounds formed in lime/MK and their stability during time, we have prepared different lime/MK ratio pastes (molar ratios). These lime/MK pastes were stored at saturated conditions (RH > 95%) and 23 ± 2 °C temperature being analysed at several ages by TGA-DTA, XRD and SEM-EDS. In this paper the results obtained are presented and discussed.

An examination of the ASTM Lime Pozzolanic Activity Test for class C fly ashes

1984 ◽  
Vol 14 (4) ◽  
pp. 499-504 ◽  
Author(s):  
S. Schlorholtz ◽  
T. Demirel ◽  
J.M. Pitt
Keyword(s):  
Pozzolanic Activity ◽  
Fly Ashes ◽  
Activity Test ◽  
Class C
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