An Investigation on Strength Properties and Microstructural Properties of Pozzolanic Mortar Mixes

The persistent reliance on traditional construction materials is of no gain to the future generation. The rate at which the natural aggregate sources are explored is alarming, and as a result, the threat of depletion of the natural materials has inspired interest in sustainable construction materials, focusing on construction and demolition wastes and local materials. In this study, an experimental insight on modified concrete, based on workability, strength and microstructural properties, is provided, in an attempt to ascertain the suitability of silica-rich aggregates (ceramic industry wastes and laterite) as a replacement for conventional fine and coarse aggregates. Various mix proportions were considered, and material batching was done by weight for concrete casting. The workability test, using slump, indicates that the flowability of the modified concrete mixes is achievable at a water-binder ratio of 0.6. The strength properties of the concrete increased with the increasing ceramic substitution for granite while increasing laterite content beyond 10% negates the strength gain by the concrete. A concrete mix containing 90% ceramic fine and 10% laterite, as fine aggregate, and 100% of cement and ceramic coarse, as binder and coarse aggregate, respectively, gave higher compressive strength (22.5 MPa), and split-tensile strength (3.6 MPa), and these results were found as comparable to the conventional concrete.

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Strength and Microstructural Properties of Mechanically-Activated Kaolin Geopolymers

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.626.926 ◽

2012 ◽

Vol 626 ◽

pp. 926-930 ◽

Cited By ~ 11

Author(s):

C.Y. Heah ◽

Kamarudin Hussin ◽

Mohd Mustafa Al Bakri Abdullah ◽

M. Bnhussain ◽

Luqman Musa ◽

...

Keyword(s):

Compressive Strength ◽

Mechanical Activation ◽

Surface Area ◽

Strength Properties ◽

Morphological Features ◽

Microstructural Properties ◽

Activation Time ◽

Sem Micrograph ◽

Low Strength

Kaolin geopolymers exhibit low strength properties due to its plate-like nature which contribute to smaller surface area for geopolymerization reactions. Layered kaolin structure only allows very little, if any, substitution of other elements. Therefore, mechanical activation is an alternative way to break the kaolin structure to become finer to change the morphological features to smoother surface, and to cause edge distortion to the kaolin particles. Rounded particles also can be produced using this technique. This mechanically-activated kaolin was used to produce mechanically-activated kaolin geopolymers in this study. From the results, compressive strength increased as mechanical activation time increased and the compressive strength increased with the ageing day. The SEM micrograph showed that the mechanically-activated kaolin geopolymers have denser structure which complies with the compressive strength measured.

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SEM Study of Tension Wood Fiber Morphology and its Effect on Paper Properties

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079061 ◽

1977 ◽

Vol 35 ◽

pp. 308-309

Author(s):

K. W. Robinson

Keyword(s):

Tension Wood ◽

Wood Fiber ◽

Strength Properties ◽

Fiber Morphology ◽

Paper Properties ◽

Pure Cellulose ◽

Short Rotation ◽

Hardwood Trees ◽

Sem Study

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.

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The Effect of Growth Rate on the Strength Properties of Sawn Beams of Silver Birch (Betula pendula Roth)

Scandinavian Journal of Forest Research ◽

10.1080/02827589950152250 ◽

1999 ◽

Vol 14 (1) ◽

pp. 18-26

Author(s):

R. A. Dunham ◽

A. D. Cameron ◽

J. A. Petty

Keyword(s):

Growth Rate ◽

Betula Pendula ◽

Strength Properties ◽

Silver Birch ◽

Betula Pendula Roth

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Spectral and Topographic Microstructure of Brain Alpha Activity During Drowsiness at Sleep Onset and REM Sleep

Journal of Psychophysiology ◽

10.1027//0269-8803.14.3.151 ◽

2000 ◽

Vol 14 (3) ◽

pp. 151-158 ◽

Cited By ~ 6

Author(s):

José Luis Cantero ◽

Mercedes Atienza

Keyword(s):

Rem Sleep ◽

Spectral Component ◽

Sleep Onset ◽

Quantitative Information ◽

Maximum Energy ◽

Alpha Activity ◽

The Other ◽

Classification Algorithms ◽

Microstructural Properties ◽

Brain States

Abstract High-resolution frequency methods were used to describe the spectral and topographic microstructure of human spontaneous alpha activity in the drowsiness (DR) period at sleep onset and during REM sleep. Electroencephalographic (EEG), electrooculographic (EOG), and electromyographic (EMG) measurements were obtained during sleep in 10 healthy volunteer subjects. Spectral microstructure of alpha activity during DR showed a significant maximum power with respect to REM-alpha bursts for the components in the 9.7-10.9 Hz range, whereas REM-alpha bursts reached their maximum statistical differentiation from the sleep onset alpha activity at the components between 7.8 and 8.6 Hz. Furthermore, the maximum energy over occipital regions appeared in a different spectral component in each brain activation state, namely, 10.1 Hz in drowsiness and 8.6 Hz in REM sleep. These results provide quantitative information for differentiating the drowsiness alpha activity and REM-alpha by studying their microstructural properties. On the other hand, these data suggest that the spectral microstructure of alpha activity during sleep onset and REM sleep could be a useful index to implement in automatic classification algorithms in order to improve the differentiation between the two brain states.

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Modification of polymer matrix for carbon fiber reinforced plastic aimed at the increase of interfacial bond strength, deformation-strength properties and stability to thermal-oxidative destruction

Polymer materials and technologies ◽

10.32864/polymmattech-2017-3-4-19-36 ◽

2017 ◽

Vol 3 (4) ◽

pp. 19-36 ◽

Cited By ~ 1

Author(s):

V. I. Dubkova ◽

O. I. Maevskaya ◽

S. F. Zhandarov

Keyword(s):

Carbon Fiber ◽

Bond Strength ◽

Strength Properties ◽

Carbon Fiber Reinforced Plastic ◽

Oxidative Destruction ◽

Interfacial Bond ◽

Interfacial Bond Strength ◽

Fiber Reinforced Plastic ◽

Reinforced Plastic ◽

Thermal Oxidative Destruction

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Co-cooking nonwoods with hardwoods

TAPPI Journal ◽

10.32964/tj13.6.19 ◽

2014 ◽

Vol 13 (6) ◽

pp. 19-24

Author(s):

TROY RUNGE ◽

CHUNHUI ZHANG

Keyword(s):

High Performance Liquid Chromatography ◽

High Performance ◽

Paper Industry ◽

Pulp And Paper Industry ◽

Strength Properties ◽

Agricultural Residues ◽

Kraft Pulping ◽

Pulp And Paper ◽

Strength Increase ◽

Xylan Content

Agricultural residues and energy crops are promising resources that can be utilized in the pulp and paper industry. This study examines the potential of co-cooking nonwood materials with hardwoods as means to incorporate nonwood material into a paper furnish. Specifically, miscanthus, switchgrass, and corn stover were substituted for poplar hardwood chips in the amounts of 10 wt %, 20 wt %, and 30 wt %, and the blends were subjected to kraft pulping experiments. The pulps were then bleached with an OD(EP)D sequence and then refined and formed into handsheets to characterize their physical properties. Surprisingly, all three co-cooked pulps showed improved strength properties (up to 35%). Sugar measurement of the pulps by high-performance liquid chromatography suggested that the strength increase correlated with enriched xylan content.

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Chemical, anatomical, and technology aspects of Eucalyptus benthamii and Eucalyptus dunii for use in an integrated pulp and paper mill

TAPPI Journal ◽

10.32964/tj14.2.73 ◽

2015 ◽

Vol 14 (2) ◽

pp. 73-81 ◽

Cited By ~ 5

Author(s):

GISELY SAMISTRARO ◽

PETER W. HART ◽

JORGE LUIZ COLODETTE ◽

RICARDO PAIM

Keyword(s):

Energy Levels ◽

Black Liquor ◽

Basic Density ◽

Paper Mill ◽

Frost Tolerance ◽

Strength Properties ◽

Kappa Number ◽

Pulp Yield ◽

Chemical Compositions ◽

Physical Strength

Eucalyptus dunii has been commercially used in southern Brazil because of its relatively good frost tolerance and adequate productivity in the winter months. More recently, interest has grown in cultivating Eucalyptus benthamii Maiden & Cambage, which presents even superior frost tolerance compared to E. dunii and is highly productive as well. The quality of E. benthamii for pulp production is not yet proven. Thus, the chemical, anatomical, and technological aspects of pulp made from E. benthamii were compared with those of E. dunii for unbleached paper production. Samples of E. benthamii chips were obtained and analyzed for their basic density, chemical composition, higher heating value, trace elemental analysis, and chip size distribution. The chips were kraft cooked using conditions that produced a 74 ± 6 kappa number. The pulps were characterized for kappa number, yield, viscosity, and morphologic characteristics (e.g., length, wall thickness, and coarseness). Black liquor was analyzed for total solids, organics, inorganics, sodium sulfide, sodium hydroxide, and sodium carbonate. Brownstocks were beaten at five different energy levels in a Valley beater, and the physical strength properties of 120 g/m² handsheets were measured to develop a beater curve. The results of this study showed differences in delignification between the two woods and lower pulp yield for E. benthamii , which are related to their chemical compositions and basic densities. The E. benthamii studied in this work exhibited higher amounts of lignin and extractives, lower carbohydrate content, and lower basic density. However, cooking a blend of the two woods afforded good results in pulping and in physical pulp properties.

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Pilot trials of hemicelluloses extraction prior to thermomechanical pulp production: Part 1

TAPPI Journal ◽

10.32964/tj10.5.21 ◽

2011 ◽

Vol 10 (5) ◽

pp. 21-28 ◽

Cited By ~ 13

Author(s):

CARL HOUTMAN ◽

ERIC HORN

Keyword(s):

Oxalic Acid ◽

Energy Savings ◽

Wood Chip ◽

Strength Properties ◽

Thermomechanical Pulp ◽

Sugar Solution ◽

Bisulfite Treatment ◽

Pilot Trials ◽

Pulp Production ◽

Production Part

Pilot data indicate that wood chip pretreatment with oxalic acid reduced the specific energy required to make thermomechanical pulp. A combined oxalic acid/bisulfite treatment resulted in 21% refiner energy savings and 13% increase in brightness for aspen. A low level of oxalic acid treatment was effective for spruce. Energy savings of 30% was observed with no significant change in strength properties. Adding bisulfite did not significantly increase the brightness of the spruce pulp. For pine, the optimum treatment was a moderate level of oxalic acid, which resulted in 34% energy savings and an increase in strength properties. For all of these treatments 1–3 w/w % carbohydrates were recovered, which can be fermented to produce ethanol. The extract sugar solution contained significant quantities of arabinose.

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