Influence of Cellulose Ethers on Fresh State Properties of Lime Mortars

Cellulose ethers (CEs) are widely used as viscosity enhancing, water retaining additives in cement based mortars. Nevertheless, studies about the effect of cellulose ethers on the properties of aerial lime-based mortars are very lack. The use of water retaining additives in lime mortars can influence not only their fresh state properties but also the pore structure and strength of hardened mortars. In this work, four different commercial cellulose ethers were added to lime mortars in order to test their influence on properties of mortars in the fresh state. Mortar rheological parameters (relative yield stress, consistency coefficient and fluidity index) were correlated with flow table tests, relative density measurements, water retention and air content in the mortars. It was found that CEs reduce the spread of lime mortars and increase air content in the mortars. The CEs are not so effective in water retention compared with other types of water retention agents. Most dosages of CEs change the behaviour of mortars from pseudoplastic to dilatant. In contrast to the effect of CEs in cement-based materials, their viscosity enhancing behavior in lime mortars is denied, due to the presence of large amounts of calcium hydroxide. From this point of view, the CEs are not so suitable to use as viscosity enhancing admixtures in lime mortars like derivatives of chitosan or guar gum.

Download Full-text

Rheological Properties of Lime Mortars with Guar Gum Derivatives

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.760.257 ◽

2018 ◽

Vol 760 ◽

pp. 257-265 ◽

Cited By ~ 8

Author(s):

Martin Vyšvařil ◽

Michaela Hegrová ◽

Tomáš Žižlavský

Keyword(s):

Yield Stress ◽

Water Retention ◽

Guar Gum ◽

Relative Yield ◽

High Water ◽

Rheological Parameters ◽

Air Content ◽

Hydroxypropyl Guar ◽

Flow Table ◽

Lime Mortars

In this paper, the behaviour of fresh lime mortars modified by etherified derivatives of guar (hydroxypropyl guar (HPG), carboxymethyl hydroxypropyl guar (CMHPG) and native guar gum (GG)) is assessed with the purpose of exploring a new application of such derivatives as lime mortar admixtures. The rheological parameters (relative yield stress, consistency coefficient and fluidity index) and viscoelastic properties were correlated with flow table tests, relative density measurements, water retention abilities of mortars and air content in mortars. Results were seen to be strongly dependent on substituents of the guar. Non-ionic derivative (HPG) exhibited the biggest impact on the yield stress and elastic properties of the mortars. The ionic CMHPG showed the thickening effect. GG had low impact on water retention, while HPG and CMHPG displayed high water retention capability.

Download Full-text

Cellulose ethers as water-retaining agents in natural hydraulic lime mortars

The proceedings of the 13th international conference "Modern Building Materials, Structures and Techniques" (MBMST 2019) ◽

10.3846/mbmst.2019.014 ◽

2019 ◽

Author(s):

Martin Vyšvařil ◽

Patrik Bayer

Keyword(s):

Water Absorption ◽

Liquid Water ◽

Frost Resistance ◽

Water Retention ◽

Point Of View ◽

Cellulose Ethers ◽

Water Absorption Coefficient ◽

Hydraulic Lime ◽

Air Content ◽

Natural Hydraulic Lime

Cellulose ethers (CEs) are commonly used as viscosity enhancing, water retaining agents in cement-based mortars. Nevertheless, studies about the effect of CEs on the properties of natural hydraulic lime-based mortars (NHL) are absent, although the use of mortars with hydraulic lime is often preferred for renovation purposes. In this study, the behavior of NHL mortars modified by four different CEs is assessed. The fresh state of mortars was characterized by water retention, air content, density a consistency. Hardened mortars were submitted to strength determination, study of pore size distribution, and thermogravimetric analyses. Transport of liquid water in the studied materials was characterized by water absorption coefficient, sorptivity, and liquid water diffusivity. Durability of the prepared mortars was monitored by frost-resistance tests. The results revealed elevated air content and water retention in mortars with increasing dose of CEs resulting in decreased density of fresh mortars. The strengths of modified mortars surpassed the reference ones at age of 180 d despite the fact that the mortars showed higher open porosity and water absorption. Enhanced porosity of mortars resulted in improvement of their frost resistance and faster carbonation. From a practical and economical point of view, the CEs dosage of 0.5% by weight of the binder appears to be sufficient.

Download Full-text

Microstructure of biopolymer-modified aerial lime mortars

MATEC Web of Conferences ◽

10.1051/matecconf/202032201023 ◽

2020 ◽

Vol 322 ◽

pp. 01023

Author(s):

Tomáš Žižlavský ◽

Martin Vyšvařil ◽

Patrik Bayer ◽

Pavla Rovnaníková

Keyword(s):

Building Materials ◽

Daily Basis ◽

Cellulose Ethers ◽

Air Content ◽

Wide Range ◽

Lime Mortars ◽

Mixed Mortar ◽

Entrained Air ◽

Intended Use ◽

Working Mechanisms

Cellulose-based viscosity-modifying admixtures are used on daily basis in a wide range of building materials, dominantly in pre-mixed mortar systems. Lately, alternative admixtures such as different “gums” have emerged. In building materials, the gums have similar viscosity-enhancingeffects as cellulose ethers with different efficiency. Various ways of production, as well as diverse working mechanisms of the biopolymers are to be considered while choosing the most suitable admixture for the intended use. Influence of alternative admixtures in several doses on the microstructure of lime mortars was studied in this paper. Mortars were prepared with the same workability and the air content in fresh mortar was determined, for it can have notable impact on microstructure of hardened mortar. Hydroxypropyl derivative of chitosan showed air entraining ability, while the carboxymethyl derivative reported slight decrease in amount of air entrained into the mixture. In the case of diutan gum, the most water-demanding admixture, the percentage of entrained air dropped with growing dose. Admixture addition increased the volume of pores in diameter lower than 0.1 μm, and in region of pores around 10 μm. Only the diutan gum affected the distribution of capillary pores, which are typical for lime mortars. Hygric properties were in correlation with air content values.

Download Full-text

Modification of water retention and rheological properties of fresh state cement-based mortars by guar gum derivatives

Construction and Building Materials ◽

10.1016/j.conbuildmat.2016.06.125 ◽

2016 ◽

Vol 122 ◽

pp. 772-780 ◽

Cited By ~ 18

Author(s):

Alexandre Govin ◽

Marie-Claude Bartholin ◽

Barbara Biasotti ◽

Max Giudici ◽

Valentina Langella ◽

...

Keyword(s):

Rheological Properties ◽

Water Retention ◽

Guar Gum ◽

Fresh State

Download Full-text

Chemical Composition and Functional Properties of Dietary Fibre Concentrates from Winemaking By-Products: Skins, Stems and Lees

Foods ◽

10.3390/foods10071510 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1510

Author(s):

María Ángeles Rivas ◽

Rocío Casquete ◽

María de Guía Córdoba ◽

Santiago Ruíz-Moyano ◽

María José Benito ◽

...

Keyword(s):

Chemical Composition ◽

Functional Properties ◽

Dietary Fibre ◽

Water Retention ◽

Point Of View ◽

Water Retention Capacity ◽

Retention Capacity ◽

Oil Retention ◽

High Antioxidant Activity ◽

By Products

The objective of this study was to evaluate, from a technological and nutritional point of view, the chemical composition and functional properties of the industrial winemaking by-products, namely skins, stems and lees. The chemical and physical characteristics, as well as the functional properties (fat and water retention and swelling capacity, antioxidant capacity, and their prebiotic effect), of the dietary fibre of these by-products were studied. The results showed that the skins, stems, and lees are rich in fibre, with the stem fibre containing the highest amounts of non-extractable polyphenols attached to polysaccharides with high antioxidant activity and prebiotic effect. Lee fibre had the highest water retention capacity and oil retention capacity. The results reveal that winemaking by-products could be used as a source of dietary fibre with functional characteristics for food applications.

Download Full-text

Plant size, nutrient composition and biomass productivity of oats and faba bean in intercropping, and the effect of controlling Rhopalosiphum padi (Hom., Aphididae) on these properties

Agricultural and Food Science ◽

10.23986/afsci.72921 ◽

1990 ◽

Vol 62 (1) ◽

pp. 21-31 ◽

Cited By ~ 1

Author(s):

Juha Helenius

Keyword(s):

Faba Bean ◽

Field Experiments ◽

Rhopalosiphum Padi ◽

Relative Yield ◽

Biomass Productivity ◽

Plant Size ◽

Damage Function ◽

Point Of View ◽

Daily Maximum ◽

Replacement Series

Effects of mixed intercropping on plant size, content of mineral nutrients and biomass yields were examined in three field experiments in Southern Finland in 1983—1985. The stand types were monocrops and replacement series of mixtures with 2/3 and 1/3 or 1/3 and 2/3 of oats (Avena sativa) and faba bean (Vicia faba), respectively. In one of the experiments control of R. padi, by means of deltamethrin sprayings, was an additional experimental factor having two levels. The height of stems or the above ground biomass of oats either were not affected or were increased by crop diversification. Bean plants remained smaller in the mixtures than in the monocrop. In plant size, there was a significant interaction between stand type and the effect of aphicide spraying: Oat benefitted most from being grown in the mixture containing most bean, and there was an indication (not statistically significant) that in these mixtures bean had proportionately higher weight loss. This result was interpreted as giving some support to the hypothesis of interspecific compensation between oats and bean against aphid damage to oats. In oats, the content of N, P, K, Ca, and Mg all decreased from the stage of inflorescence emergence to the stage of the onset of milk development. Mixed cropping increased the content in oats of all these nutrients except Ca. At the same time, contents of P and K in bean were decreased. The changes in growth form and composition in oats induced by intercropping are discussed from the point of view of host plant relationship and damage function of the aphid pest. In terms of relative yield total (RYT), there was no overyielding in the dry matter, and in one case only was there overyielding in the nitrogen. During the period of population growth of R. padi, the daily maximum temperatures within the canopy were higher in the mixtures than in the monocrop of oats.

Download Full-text

Influence of Cellulose Ethers on the Consistency, Water Retention and Adhesion of Renovating Plasters

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/471/3/032020 ◽

2019 ◽

Vol 471 ◽

pp. 032020

Author(s):

Waclaw Brachaczek

Keyword(s):

Water Retention ◽

Cellulose Ethers

Download Full-text

Investigation of the Potential Use of Curauá Fiber for Reinforcing Mortars

Fibers ◽

10.3390/fib8110069 ◽

2020 ◽

Vol 8 (11) ◽

pp. 69

Author(s):

Afonso R. G. de Azevedo ◽

Sergey Klyuev ◽

Markssuel T. Marvila ◽

Nikolai Vatin ◽

Nataliya Alfimova ◽

...

Keyword(s):

Water Retention ◽

Natural Fibers ◽

Northern Region ◽

Technological Properties ◽

Wetting And Drying ◽

Air Content ◽

Naoh Solution ◽

Potential Use ◽

Reference Mixture ◽

Curauá Fiber

Curauá is a bromeliad of Amazonian origin, present in some states in the northern region of Brazil and in other countries in South America. Its natural fibers have several technological advantages for application in composite materials. The objective of this research was to investigate the potential of using the fiber of Curauá as a reinforcement element in mortars for wall covering. Mortars were made with a 1:1:6 ratio (cement:lime:sand) in relation to their mass, evaluating the effect of adding 1%, 2% and 3% of Curauá fiber natural and fiber treated in NaOH solution in relation to the mass of cement, compared to the reference mixture (0%). Technological properties such as consistency, water retention and incorporated air content, compressive strength, water absorption and durability in wetting and drying cycles were evaluated. The results showed that the addition of the Curauá fiber causes an improvement in the mechanical properties of mortars, and at levels of addition 3% or more, it causes problems of workability and incorporation of air into the dough, thus, the fiber addition in 2% presented better results for application in coating mortars, in relation a Brazilian norm, even improving the durability of external coatings.

Download Full-text

Effect of Granite Residue Incorporation on the Behavior of Mortars

Materials ◽

10.3390/ma12091449 ◽

2019 ◽

Vol 12 (9) ◽

pp. 1449 ◽

Cited By ~ 27

Author(s):

Afonso Rangel Garcez de Azevedo ◽

Markssuel Teixeira Marvila ◽

Laimara da Silva Barroso ◽

Euzébio Bernabé Zanelato ◽

Jonas Alexandre ◽

...

Keyword(s):

Water Retention ◽

Building Materials ◽

Building Construction ◽

Squeeze Flow ◽

Technological Properties ◽

Rheological Characterization ◽

Ornamental Stone ◽

Fresh State ◽

The World ◽

Residue Incorporation

Civil construction is one of the most resource-consuming sectors in the world. For this reason, the last years have witnessed the study of reusing industrial residues in building materials. The ornamental stone processing industry has a considerable environmental liability related to residue generation during the cutting stages of granite blocks. The objective of this work is to analyze the viability of incorporating granite residues, up to 100%, to substitute sand in coating mortars for building construction. Mortars without residue, as control, and incorporated with 20, 40, 60, 80, and 100% of granite residue were subjected to consistency tests, incorporated air and water retention together with the rheological characterization using the squeeze-flow and the dropping-ball methods. The results show that mortars with 40% granite residues presented greater plastic deformation, helping their applicability by also presenting improved technological properties in the fresh state.

Download Full-text