The Influence of Limestone Additions on the Rheological Properties and Water Retention Value of Portland Cement Slurries

2009 ◽  
pp. 24-24-6 ◽  
Author(s):  
CS Neto ◽  
VC Campiteli
Keyword(s):  
Portland Cement ◽  
Rheological Properties ◽  
Water Retention ◽  
Water Retention Value

scholarly journals The Influence of Hydrated Lime and Cellulose Ether Admixture on Water Retention, Rheology and Application Properties of Cement Plastering Mortars

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5487
Author(s):  
Edyta Spychał ◽  
Ryszard Dachowski
Keyword(s):  
Rheological Properties ◽  
Water Retention ◽  
Hydrated Lime ◽  
Plastic Viscosity ◽  
Subjective Rating ◽  
Cellulose Ether ◽  
Technological Properties ◽  
Water Retention Value ◽  
Rheological Measurements ◽  
Standard Tests

In this article, the effect of hydrated lime and cellulose ether on the water retention, rheology, and application properties of plasters was studied. For mortars, the consistency, bulk density, and water retention were tested. Rheological measurements of pastes included yield stress and plastic viscosity. In addition to standard tests of mortars and examining the rheological properties of the pastes, a proprietary method for testing the application properties was proposed. The obtained research results made it possible to evaluate the performance of the tested plasters. An attempt was also made to correlate the rheological properties of pastes (plastic viscosity) to the water retention value. The influence of hydrated lime and cellulose ether on selected properties of pastes and plasters was also presented using the statistical Box–Behnken method. The subjective rating of an expert plasterer confirmed the necessity of the modification of plastering mortars with hydrated lime and cellulose ether. As shown, modification of cement plastering mortar with hydrated lime and cellulose ether at the same time allows obtaining a material with favorable technical and technological properties, especially mortars applied by machine.

scholarly journals The Influence of Cement Type on the Properties of Plastering Mortars Modified with Cellulose Ether Admixture

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7634
Author(s):  
Edyta Spychał ◽  
Przemysław Czapik
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Portland Cement ◽  
Bulk Density ◽  
Water Retention ◽  
High Water ◽  
Cellulose Ether ◽  
Cement Type ◽  
Water Retention Value ◽  
Mineral Additives

In this article, the effect of cement type on selected properties of plastering mortars containing a cellulose ether admixture was studied. In the research, commercial CEM I Portland cement, CEM II and CEM III, differing in the type and amount of mineral additives, and cement class, were used as binders. Tests of consistency, bulk density, water retention value (WRV), mechanical properties and calorimetric tests were performed. It was proved that the type of cement had no effect on water retention, which is regulated by the cellulose ether. All mortars modified with the admixture were characterized by WRV of about 99%. High water retention is closely related to the action of the cellulose ether admixture. As a result of the research, the possibility of using cement with additives as components of plasters was confirmed. However, attention should be paid to the consistency, mechanical properties of the tested mortars and changes in the pastes during the hydration process. Different effects of additives resulted from increasing or decreasing the consistency of mortars; the flow was in the range from 155 mm to 169 mm. Considering the compressive strength, all plasters can be classified as category III or IV, because the mortars attained the strength required by the standard, of at least 3.5 MPa. The processes of hydration of pastes were carried out with different intensity. In conclusion, the obtained results indicate the possibility of using CEM II and CEM III cements to produce plastering mortars, without changing the effect of water retention.

Effects of a PFI refiner’s operational parameters on the swellability of recycled fiber

TAPPI Journal ◽  
2020 ◽  
Vol 19 (5) ◽  
pp. 239-246
Author(s):  
XIAONING SHEN ◽  
BO LI ◽  
WENXUAN MO ◽  
XIN-SHENG CHAI
Keyword(s):  
Water Retention ◽  
Fiber Quality ◽  
Operational Parameters ◽  
Fiber Morphology ◽  
Water Retention Value ◽  
Electron Microscopic ◽  
Mathematical Relation ◽  
Scanning Electron Microscopic ◽  
Recycled Fiber ◽  
Scanning Electron

This paper presents data on the effects of operational parameters (number of revolutions, linear pressure, and gap) of the PFI refiner on the swellability of recycled fiber, which was characterized by water retention value (WRV). The results showed that the increase of recycled fiber’s WRV was proportional to the number of revolutions and the linear pressure, but inversely proportional to the gap. The mathematical relation between these parameters and the fiber WRV could be described by an empirical model for gaps greater than 0.1 mm. Scanning electron microscopic images of fiber morphology showed that the basic framework of fibers could be maintained with the gap greater than 0.1 mm, but was destroyed with smaller gaps. This model provides a technical reference for quantitative control of refining treatment and an effective method for improving recycled fiber quality.

scholarly journals Impact of Superplasticizer on Rheological Properties and Hardening Process of Different Portland Cement Pastes

2015 ◽  
Vol 21 (1) ◽  
Author(s):  
Jadvyga Žvironaitė ◽  
Modestas Kligys ◽  
Ina Pundienė ◽  
Jolanta Pranckevičienė
Keyword(s):  
Portland Cement ◽  
Rheological Properties ◽  
Cement Pastes ◽  
Hardening Process

New model for predicting tensile strength and density of eucalyptus handsheets based on an activation parameter calculated from fiber distribution characteristics

Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Iiro Pulkkinen ◽  
Juha Fiskari ◽  
Ville Alopaeus
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Wall Thickness ◽  
Water Retention ◽  
Activation Parameter ◽  
Water Retention Value ◽  
Data Set ◽  
Network Activation ◽  
Fiber Wall ◽  
Fiber Segment

Abstract The activation parameter developed is based on the fiber wall thickness distribution, fiber curl distribution, and water retention value of the unrefined fibers. The mechanical properties of paper that contain chemical pulp depend, among other things, on the free fiber segment activation between fiber-fiber crossings that is created during drying. Experimental data revealed that the degree of fiber swelling is responsible together with the fiber shape factor (curl) and fiber wall thickness for the extent of fiber network activation. The amount of bonding between fibers also affects fiber segment activation. Based on the experimental data, it was deduced that interfiber bonding ability of fibers, characterized as the water retention value, was mainly responsible for the development of handsheet density. Tensile index development was more affected by the morphology of fibers, which was the main determinant for high activation potential of fibers. Factor analysis was used to identify the main causes of variation for a refining data set of 20 Eucalyptus grandis samples. Three independent descriptors were found to be responsible for the majority of the variation: the bonding and activation factor, the factor of microcompressions, and the factor of fiber wall thickness and fiber curl. The activation parameter developed in this study can be used to determine the effect of fiber segment activation and inter-fiber bonding on the inplane mechanical properties of paper.

The Influence of Hydrated Lime, Portland Cement and Cement Dust on Rheological Properties of Recycled Cold Mixes with Foamed Bitumen

2017 ◽  
Author(s):  
Przemysław Buczynski ◽  
Marek Iwanski
Keyword(s):  
Portland Cement ◽  
Rheological Properties ◽  
Complex Modulus ◽  
Hydrated Lime ◽  
Laboratory Evaluation ◽  
Cement Kiln ◽  
Direct Tension ◽  
Stiffness Modulus ◽  
Hydraulic Binder ◽  
Foamed Bitumen

This article presents a laboratory evaluation of the viscoelastic properties of recycled base courses produced with different fillers. The aim of this study was to investigate the influence of loading time and temperature on the complex modulus (E*) and the phase angle (6) of recycled base courses with respect to selected additives used. The mixtures contained reclaimed asphalt pavement RAP, crushed stone from existing base courses and virgin aggregate. Foamed bitumen 50/70 at 2.5% was used as a binder. The hydraulic binder constituted 3.0% of the recycled base course mixture. Portland cement, hydrated lime and cement kiln dust CKD were added as fillers. Evaluation of rheological properties of recycled base courses according to selected additives was carried out to the procedure set out in EN 12697-26 annex D. The evaluation of stiffness modulus was conducted in the direct tension- compression test on cylindrical samples (DTC-CY). The samples were subjected to the cycles of sinusoidal strain with an amplitude Bo < 25μB. All tests were performed over a range of temperatures (5 ºC, 13 ºC, 25 ºC, 40 ºC) and loading times (0.1 Hz, 0.3 Hz, 1 Hz, 3 Hz, 10 Hz, 20 Hz). The results were used to model stiffness modulus master curves of the recycled base courses containing selected additives in the hydraulic binder.

Recycled fiber treated with NaOH/urea aqueous solution: effects on physical properties of paper sheets and on hornification

2018 ◽  
Vol 33 (4) ◽  
pp. 651-660 ◽  
Author(s):  
Yingju Miao ◽  
Yunfei Zhi ◽  
Heng Zhang ◽  
Ying Chen ◽  
Shaoyun Shan ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Physical Properties ◽  
Water Retention ◽  
Crystalline Region ◽  
Cellulose Film ◽  
Reinforced Concrete Structure ◽  
Water Retention Value ◽  
Fiber Network ◽  
Urea Aqueous Solution ◽  
Intramolecular Hydrogen

Abstract Hydrogen bonding among fiber microfibrils is the primary cause of fiber hornification, wherein NaOH/urea aqueous solution precooled to −13 °C can disassemble inter- and intramolecular hydrogen bonds. Whether hornified fibers treated with this process can significantly improve fiber swelling ability and physical properties of the resulting paper sheets remains a problem. In this investigation, the 6th cycle fiber was pretreated with this procedure, and the water retention value of the fiber before and after treatment and the physical properties of the resulting paper sheets were studied. The results indicate that the lignin decline, complete swelling of flat fiber, filling of cellulose film between the interfiber network, and decreasing crystalline region all contribute to the increase in water retention value. The water retention value of repaired fiber is equivalent to that of virgin pulp, and hornification reverses by 89 %. In addition, the cellulose film filling among the fiber network constructs a similar reinforced concrete structure, which causes the tear, burst, and tensile index of the resulting paper sheets to increase by 145 %, 98 %, and 43 %, respectively.

scholarly journals Calorimetry in the studies of by-pass cement kiln dust as an additive to the calcium aluminate cement

2019 ◽  
Vol 138 (6) ◽  
pp. 4561-4569 ◽  
Author(s):  
Wiesława Nocuń-Wczelik ◽  
Katarzyna Stolarska
Keyword(s):  
Portland Cement ◽  
Rheological Properties ◽  
Calcium Aluminate ◽  
Calcium Aluminate Cement ◽  
Cement Kiln ◽  
Phase Assemblage ◽  
Chemical Shrinkage ◽  
High Calcium ◽  
Kinetics Of ◽  
Aluminate Cement

Abstract The studies focused on the kinetics of early hydration in the high-calcium aluminate cement (CAC 70)—by-pass cement kiln dusts (BPCKD)—mixtures. For this purpose, the mixtures of cement with this additive or with some potential constituents of dusts were produced. The microcalorimeter was applied to follow the kinetics of hydration. The investigations with the aim of finding the relationship between the components of initial mixtures and the modification of hydration process were carried out. The rheological properties were characterized, and the chemical shrinkage characteristics were produced. The phase assemblage characterization and microscopic observations were done as well. In case of the high-calcium aluminate-based binders, the modification of setting process was observed; the rheological properties and chemical shrinkage were affected too. The acceleration of heat evolution—the shortening of so-called induction period in the presence of BPCKD additive—was observed. The results were compared to those obtained for the CAC with ordinary Portland cement additive. The results of calorimetric measurements are discussed in terms of the chemical and phase assemblage of this additive as compared to the Portland cement clinker precursors and potassium chloride—the solid and liquid components of the dust.

Use of Cellulose-Containing Fillers in Composites with Polypropylene

1970 ◽  
Vol 17 (2) ◽  
pp. 150-154
Author(s):  
Marianna LAKA ◽  
Svetlana CHERNYAVSKAYA ◽  
Galia SHULGA ◽  
Viktor SHAPOVALOV ◽  
Andrej VALENKOV ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Shear Modulus ◽  
Rapeseed Oil ◽  
Water Retention ◽  
Raw Materials ◽  
Water Retention Value ◽  
Water Vapour Sorption ◽  
Recycled Polypropylene ◽  
Sulphate Pulp

The composites, containing recycled polypropylene and fillers, obtained from different lignocellulosics by the thermocatalytic destruction method, were investigated. Birch sawdust, newsprint wastes, cotton residues and wood bleached sulphate pulp were used as raw materials for obtaining fillers. The indices of mechanical properties (tensile strength, modulus of elasticity, deformation at break, shear modulus, toughness, twisting moment) of the composites' samples were determined. It has been found that the obtained composites have relatively good mechanical properties. Better results were obtained, using fillers from sawdust and wood pulp. After treating the fillers with rapeseed oil, their water vapour sorption and water retention value (WRV) decreased. In this case, the strength of the composites was higher.http://dx.doi.org/10.5755/j01.ms.17.2.484

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