Fresh state properties of lime mortars with foam glass dust

Flax oil has been used as mortar improving, hydrophobic, admixture already in ancient times. The paper describes the identification of flax oil in mosaic mortar from ca. 1900 by help of FTIR spectroscopy. This historic mortar was reproduced by nowadays raw materials and the influence of flax oil on consistency and air entraining of fresh mortar was tested. It was found that already small amount of oil caused significant air entrainment, which, simultaneously with water repellency action, may contribute to higher durability of mortar with oil admixture. The flux oil influenced also consistency of mortar; its presence caused higher flow value of mortar. Moreover, the introduction of the paper summarizes principal knowledge about action of natural admixtures in lime mortars and plasters on basis of current literature.

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Effect of natural lightweight aggregate on fresh state properties of lime mortars

10.1063/5.0041828 ◽

2021 ◽

Author(s):

Tomáš Žižlavský ◽

Martin Vyšvařil

Keyword(s):

Lightweight Aggregate ◽

Lime Mortars ◽

Fresh State

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Influence of Cellulose Ethers on Fresh State Properties of Lime Mortars

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.276.69 ◽

2018 ◽

Vol 276 ◽

pp. 69-74 ◽

Cited By ~ 5

Author(s):

Martin Vyšvařil ◽

Michaela Hegrová ◽

Tomáš Žižlavský

Keyword(s):

Water Retention ◽

Guar Gum ◽

Relative Yield ◽

Point Of View ◽

Rheological Parameters ◽

Cellulose Ethers ◽

Air Content ◽

Flow Table ◽

Lime Mortars ◽

Fresh State

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.

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Control of the Structure and Properties of Acoustic Materials on the Basis of Foam Glass Composites

Stroitel nye Materialy ◽

10.31659/0585-430x-2018-760-6-41-44 ◽

2018 ◽

Vol 760 (6) ◽

pp. 41-44 ◽

Cited By ~ 2

Author(s):

V.S. LESOVIK ◽

◽

S.V. ALEKSEEV ◽

I.V. BESSONOV ◽

S.S. VAISERA ◽

...

Keyword(s):

Foam Glass ◽

Structure And Properties ◽

Glass Composites

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Some Seventy Years in the Shrouding of Mining Residue Deposits for Environmental Protection

Water Science & Technology ◽

10.2166/wst.1983.0027 ◽

1983 ◽

Vol 15 (2) ◽

pp. 85-102

Author(s):

F D Cartwright

Keyword(s):

Environmental Protection ◽

Impervious Surfaces ◽

Dust Suppression ◽

Mine Dumps ◽

Fresh State

Isolation of mine dumps and slimes dams to prevent damage to the environment. There are considered the need for isolation, the use of vegetation essentially for dust suppression and material bonding to create impervious surfaces in order to lead off precipitation in a fresh state and suppress dust at the same time.

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Use of Posidonia oceanica fibres in lime mortars

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.123881 ◽

2021 ◽

Vol 298 ◽

pp. 123881

Author(s):

M. Stefanidou ◽

V. Kamperidou ◽

A. Konstantinidis ◽

P. Koltsou ◽

S. Papadopoulos

Keyword(s):

Posidonia Oceanica ◽

Lime Mortars

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Estimation of the Age of Architectural Heritage Objects by Microstructural Changes of Calcite in Lime Mortars of Ancient Brickwork and Masonry

Buildings ◽

10.3390/buildings11060240 ◽

2021 ◽

Vol 11 (6) ◽

pp. 240

Author(s):

Vladimir Kotlyar ◽

Victoria Pishchulina ◽

Alexey N. Beskopylny ◽

Besarion Meskhi ◽

Yury Popov ◽

...

Keyword(s):

18Th Century ◽

Degree Of Crystallinity ◽

Architectural Heritage ◽

Natural Conditions ◽

Relative Age ◽

Lime Mortars ◽

Powder Samples ◽

Diffraction Patterns ◽

Cultural Monuments ◽

The Degree Of Crystallinity

Determining the age of ancient architectural and cultural monuments is a significant scientific problem. An approach based on the transformation of portlandite into calcite and subsequent recrystallization of calcite is considered, which allows for estimating the relative age of ancient brickworks for local groups of historic buildings based on the results of diffraction studies of powder samples of carbonate mortars and measurements of samples with a known age. This article presents the results of the study of lime mortars of ancient brickwork. Under natural conditions, the process of transformation of portlandite into calcite takes from 100 to 200 years. The rate of this process is influenced by temperature, humidity, peculiarities of interaction with carbon dioxide contained in the air, etc. Examples show that portlandite is completely transformed into calcite in masonry mortars of the 18th century and that portlandite is not found in older mortars. It was determined that after the transformation of portlandite into calcite, an increase in the degree of recrystallization of calcite is observed, which manifests itself in powder diffraction patterns in the relative broadening of the diffraction peak of calcite hkl 104. In a detailed study, an estimate of the peak width at half maximum (FWHM) associated with the degree of crystallinity is effective. The actual data are given, which show that in older lime mortars the degree of recrystallization of calcite is higher than in younger ones. This fact makes it possible to indirectly determine the relative age of brickwork and masonry of various buildings of architectural heritage, which is especially relevant for the objects with the use of lime mortars of the northern provinces of the Byzantine Oecumene and other periods of various cultures.

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The performance of ultra-lightweight foamed concrete incorporating nanosilica

Archives of Civil and Mechanical Engineering ◽

10.1007/s43452-021-00234-2 ◽

2021 ◽

Vol 21 (2) ◽

Author(s):

Mohamed Abd Elrahman ◽

Pawel Sikora ◽

Sang-Yeop Chung ◽

Dietmar Stephan

Keyword(s):

Wall Thickness ◽

Probabilistic Approach ◽

Drying Shrinkage ◽

Dry Density ◽

Optimal Dosage ◽

X Ray ◽

Mechanical And Physical Properties ◽

Fresh State ◽

Foamed Concrete ◽

The Stability

AbstractThis paper aims to investigate the feasibility of the incorporation of nanosilica (NS) in ultra-lightweight foamed concrete (ULFC), with an oven-dry density of 350 kg/m3, in regard to its fresh and hardened characteristics. The performance of various dosages of NS, up to 10 wt.-%, were examined. In addition, fly ash and silica fume were used as cement replacing materials, to compare their influence on the properties of foamed concrete. Mechanical and physical properties, drying shrinkage and the sorption of concrete were measured. Scanning electron microscopy (SEM) and X-ray microcomputed tomography (µ-CT) and a probabilistic approach were implemented to evaluate the microstructural changes associated with the incorporation of different additives, such as wall thickness and pore anisotropy of produced ULFCs. The experimental results confirmed that the use of NS in optimal dosage is an effective way to improve the stability of foam bubbles in the fresh state. Incorporation of NS decrease the pore anisotropy and allows to produce a foamed concrete with increased wall thickness. As a result more robust and homogenous microstructure is produced which translate to improved mechanical and transport related properties. It was found that replacement of cement with 5 wt.-% and 10 wt.-% NS increase the compressive strength of ULFC by 20% and 25%, respectively, when compared to control concrete. The drying shrinkage of the NS-incorporated mixes was higher than in the control mix at early ages, while decreasing at 28 d. In overall, it was found that NS is more effective than other conventional fine materials in improving the stability of fresh mixture as well as enhancing the strength of foamed concrete and reducing its porosity and sorption.

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