Academic literature on the topic 'Capillary water absorption'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Capillary water absorption.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Capillary water absorption"
1
Xiao, Qianhui, Xiaolin Liu, Jisheng Qiu, and Yangyang Li. "Capillary Water Absorption Characteristics of Recycled Concrete in Freeze-Thaw Environment." Advances in Materials Science and Engineering 2020 (May 7, 2020): 1–12. http://dx.doi.org/10.1155/2020/1620914.
Full textAbstract:
In order to study the capillary water absorption characteristics of recycled concrete (RAC) with different replacement rates of recycled coarse aggregate (0, 20%, 40%, and 60%) in freeze-thaw environment, the standard test method of measuring the water absorption of hydraulic cement concrete (ASTM C1585-13) was adopted, and the influence mechanism of freeze-thaw cycle and replacement rate of recycled coarse aggregate on the capillary water absorption of RAC was analyzed, and a prediction model of initial capillary water absorption of RAC in freeze-thaw environment was established. The results show that when the freeze-thaw environment is the same, the greater the replacement rate of recycled coarse aggregate, the greater the cumulative water absorption of RAC, the faster the initial capillary water absorption, and the stronger the capillary water absorption; when the freeze-thaw environment is different, the more the freeze-thaw cycles, the greater the cumulative water absorption of RAC with the same replacement rate of recycled coarse aggregate, the faster the initial capillary water absorption, and the stronger the capillary water absorption. The prediction model of RAC initial capillary water absorption established by regression analysis has high accuracy, which can be used to predict RAC capillary water absorption performance and provide theoretical basis for the research of RAC frost resistance durability.
2
Ardiani, Septia, Handika Rahmayanti, and Nurul Akmalia. "The Study of Paper Capillarity with a Simple Technique." Jurnal Ilmiah Publipreneur 8, no. 1 (August 30, 2020): 34–47. http://dx.doi.org/10.46961/jip.v8i1.55.
Full textAbstract:
The study of water absorption by capillarity on paper with a simple technique is simple but important to do to inform the public about the characteristics of paper and for the development of research on the absorption of different types of paper. In this study, five types of paper were used, namely HVS paper, cardboard, tissue paper, concord paper and buffalo paper. In the capillary water absorption test on paper, the physical quantities analyzed are the water absorption, the absorption time and the water absorption rate. The capillarity of the paper is a comparison of the rate of water absorption by the paper which is analyzed using the straight line movement approach. The value of water absorption is estimated using the ratio between the height of water absorption and the time absorption. Based on the results of the capillary test on paper, it was found that the water absorption height for the five types of paper increases with increasing absorption time. The highest water absorption capacity is tissue paper, which is 7.4 ± 0.2 cm every 180 seconds. While the lowest water absorption capillarity is HVS paper which is 0.5 ± 0.1 cm at the 180th second. Cardstock and buffalo paper have almost the same water absorption value and are higher than HVS paper and match. The absorption speed which is almost the same between cardboard and buffalo paper is due to the fact that both belong to the same type of paper, namely printing paper.
3
Liu, Xue Wu, Jin Bo Yang, Kai Quan Xia, Peng Zhang, and Zhan Guo Li. "Capillary Absorption Dynamics for Cementitious Material Considering Water Evaporation and Tortuosity of Capillary Pores." Advanced Materials Research 821-822 (September 2013): 1213–18. http://dx.doi.org/10.4028/www.scientific.net/amr.821-822.1213.
Full textAbstract:
This paper presents the theoretical analysis of capillary absorption dynamics for cemementitious material. Fractal theory is applied to analyse tortuosity of capillary pores in cementitious material and a definition of tortuosity is given. The dynamic equation of capillary absorption considering water evaporation and tortuosity of capillary pores is derived. Based on the dynamic model, the capillary coefficient and sorptivity of concrete are explained theoretically. In absorption test, water evaporation is one of the main reasons caused variations from linearity between water absorption height and the square root of time, or between water amount absorbed and the square root of time. In cementitious material, the evaporation rate is very small compare to capillary flow velocity at the initial time of absorption test. For simplification of testing procedure, there is no meaning to modify absorption test.
4
Gao, Qi, Zhiming Ma, Jianzhuang Xiao, and Fuan Li. "Effects of Imposed Damage on the Capillary Water Absorption of Recycled Aggregate Concrete." Advances in Materials Science and Engineering 2018 (October 8, 2018): 1–12. http://dx.doi.org/10.1155/2018/2890931.
Full textAbstract:
Capillary water absorption of concrete is closely related to its pore structure, permeability, and durability. This paper intensively investigates the effects of imposed damage, including freeze-thaw damage and loading damage, on the capillary water absorption of recycled aggregate concrete (RAC). Freeze-thaw cycle test, loading test, and the experiment of capillary water absorption were carried out, respectively. The results demonstrate that the addition of recycled coarse aggregate (RCA) results in the increase in the capillary absorption behavior of RAC without imposed damage, and there exists a linear correlation between the behaviors of capillary water absorption and chloride penetration of RAC. The imposed freeze-thaw damage or load damage of RAC boosts with the increase of RCA replacement percentages after suffering the same freeze-thaw cycles or loading level. The imposed freeze-thaw damage and load damage further lead to the increase in the capillary water absorption of RAC, and the capillary absorption coefficient of RAC increases linearly with the increased RCA replacement percentages, after suffering the same freeze-thaw cycles or loading level. Furthermore, capillary absorption coefficient increases linearly with the growth of imposed freeze-thaw damage or load damage degree, which can be used to estimate the capillary absorption behavior of RAC exposed to the extreme environment.
5
Hall, Christopher. "Capillary water absorption by a porous cylinder." Journal of Building Physics 42, no. 2 (August 21, 2017): 120–24. http://dx.doi.org/10.1177/1744259117724523.
Full textAbstract:
Capillary absorption (imbibition) of water by a porous cylinder is described by means of a Sharp-Front model. The cumulative absorption increases as (time)1/2 at early times, but more slowly as the wet front approaches the cylinder axis. Results are given in terms of dimensionless variables. Experimental data on plaster cylinders are in good agreement with theory. Estimates of the sorptivity and effective porosity of the material can be obtained. The model may be useful in testing drilled cores and may also be applied to radial flow through the wall of a porous tube (hence to conduits and arches).
6
Tomašić, Ivan, Dražen Lukić, Nataša Peček, and Ana Kršinić. "Dynamics of capillary water absorption in natural stone." Bulletin of Engineering Geology and the Environment 70, no. 4 (February 11, 2011): 673–80. http://dx.doi.org/10.1007/s10064-011-0355-x.
Full text
7
Wang, Ru, Dao Xun Ma, and Pei Ming Wang. "Waterproof Performance of Polymer-Modified Cement Mortar." Advanced Materials Research 687 (April 2013): 213–18. http://dx.doi.org/10.4028/www.scientific.net/amr.687.213.
Full textAbstract:
This paper tested the capillary water absorption, impermeability and cracking of cement mortars modified with three polymers respectively and founded the correlation of cracking with the waterproof performance. The results show that with the polymer content increasing, especially as the polymer/cement ratio (mp/mc) increases from 0% to 5%, the reduction in the capillary water absorption and the penetration depth of water into mortar is significant. When the mp/mc is more than 15%, the increase of the mp/mc in all mortars has little effect on the capillary water absorption and the penetration depth. For the purpose of reducing the cracking weighted value, the styrene-butadiene rubber (SBR) dispersion and the styrene-acrylic copolymer (SAE) powder are superior to the SAE dispersion. Regardless what kinds of polymers, the capillary water absorption and the penetration depth of water into mortar show exponential growth with the increasing cracking weighted value.
8
Ma, Dao Xun, Yan Liu, and Yong Lai. "The Influence of Pore Structure on the Waterproof Performance of Polymer Modified Mortar." Applied Mechanics and Materials 584-586 (July 2014): 1130–34. http://dx.doi.org/10.4028/www.scientific.net/amm.584-586.1130.
Full textAbstract:
This paper tested the pore structure, capillary water absorption and impermeability of cement mortars modified with three polymers respectively, establishing the relationship between the pore structure and waterproof performance. The results show that with the polymer dosage growing, especially as the polymer/cement ratio (mp/mc) increases from 0% to 5%, the reduction in the capillary water absorption and the penetration depth of water into mortar is significant. In themp/mcrange of 0%~20% the open porosity presents a gradual decrease trend. The capillary water absorption and the penetration depth of water into mortar show linear growth and exponential growth respectively with the open porosity increasing.
9
Zhu, Ya Guang, Pei Zhen Xu, Qiu Yi Li, and Chuan Li. "Influence of Water Repellent Surface Impregnation on Water Absorption Properties of Recycled Aggregate Concrete." Applied Mechanics and Materials 71-78 (July 2011): 5011–14. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.5011.
Full textAbstract:
This paper aimed to investigate the influence of using silane surface water repellent treatment on the capillary water absorption properties of recycled aggregate concrete. In this study, two types of coarse aggregate, natural aggregates and recycled aggregates were used, and the surface water repellent treatment of concrete was produced by brushing 100g/m2 and 200g/m2 of paste. It was found that the silane impregnation depth of recycled concrete was deeper than that of natural concrete, and the surface treatment was more effective in the improvement of capillary water absorption properties of recycled aggregate concrete than the natural aggregate concrete.
10
Wang, Li Cheng, and Shu Hong Li. "Numerical Solutions for Capillary Absorption by Cementitious Materials." Applied Mechanics and Materials 94-96 (September 2011): 1560–63. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.1560.
Full textAbstract:
Capillary absorption is essential to mass migration in cementitious materials. Based on previous studies, capillary rise involving gravity effects is of much greater interest in porous building materials because equilibrium is attained at the wetting front when gravitational force balance the capillary force. In this paper, two different solution forms, semi-analytical and numerical, are presented to account for the gravity effect for realistical prediction of water penetration process. The former is stable against small perturbation proved by Stepanyants [1]. The comparison of predicted results by the two methods confirms the reliability of the technique in estimating water transport.
Dissertations / Theses on the topic "Capillary water absorption"
1
Lieboldt, Matthias, and Viktor Mechtcherine. "Einfluss von Rissen auf den Feuchtetransport in textilbewehrtem Beton." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-77943.
Full textAbstract:
In diesem Beitrag wird die Wasserabsorption und die Wasserpermeabilität von axial vorbelasteten Prüfkörpern aus textilbewehrtem Beton (TRC) und biegebelasteten Verbundprüfkörpern (Normalbeton + TRC) im gerissenen Zustand untersucht. Durch in situ Permeabilitätsmessungen wird das dehnungsabhängige Transportverhalten im einaxialen Zugversuch beobachtet und mittels eines analytischen Modells beschrieben. Es besteht eine ausgeprägte Abhängigkeit der Transportraten von Flüssigkeiten zu relevanten Risscharakteristika (Rissanzahl, Rissbreite). Weiterhin wurden Selbstheilungseffekte von feinen Rissen infolge einer zyklischen Wasserbeaufschlagung beobachtet. Die Feuchteverteilung in einer gerissenen Normalbetonprobe und einer Verbundprobe (Normalbeton + TRC) wird mit Hilfe der Neutronenstrahlradiographie zeit- und ortsaufgelöst dargestellt. Das Eindringen von Wasser wird anhand der Messungen qualitativ vorgestellt und diskutiertIn this study water absorption and water permeability were tested on uniaxially preloaded, cracked specimens made of textile reinforced concrete (TRC) and cracked composite specimens (ordinary concrete + TRC) preloaded in bending. The influence of imposed strain on the permeation of water was observed in-situ by using uniaxial tensile tests and described by an analytical model. The transport values for the cracked material correlated with the cracks’ characteristics (number of cracks, crack width). Furthermore, the effect of self-healing phenomena on the transport properties of TRC was considered. The distribution of water in cracked ordinary concrete and cracked composite specimens was studied by means of neutron radiography which provided with a high spatial and temporal resolution. The penetration of water is presented qualitatively and discussed
2
Vláčilíková, Michaela. "Měření infiltrace v terénu pomocí MiniDiskového infiltrometru." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409739.
Full textAbstract:
The diploma thesis deals with measuring of infiltration by MiniDisk method and its evaluation, but also with analysis of intact and grab soil sample, by means of which it is possible to assess the soil quality. The measurements took place on 30.4.2019, 4.5.2019, 12.5.2019, 2.6.2019, 30.6.2019, 2.7.2019, 31.8.2019 and 21.9.2019 on grassland near the town of Luhačovice. Grab and intact soil samples were taken from the upper soil layer and processed in a pedological laboratory. The Zhang method was used to evaluate the infiltration results. The results of soil analyzes and infiltration were processed numerically, plotted and subsequently described and compared.
3
Cantarelli, Gustavo Martins. "PERCOLAÇÃO DE ÁGUA EM CONCRETOS COM ELEVADOS TEORES DE ESCORIA E CINZA VOLANTE COM ADIÇÃO DE CAL." Universidade Federal de Santa Maria, 2007. http://repositorio.ufsm.br/handle/1/7678.
Full textAbstract:
Conselho Nacional de Desenvolvimento Científico e TecnológicoThe study of concrete structures durability necessarily passes by the study of covercrete and by the understanding of the factors that affect the features of this superficial layer. The use of high contents of mineral addictions on the concrete influences meaningfully the resistance of the covering layer to the chemical attack and on the pores structure. This dissertation aimed to analyze, through the obtained results in the tests of capillary water absorption, according to the RILEM TC 116 PCD Recommendation, and to the diffusion of water held following the directives DAN et al (1988) presented by Isaia (1995), based on publications of CSTB, the percolation of water on concrete covering layer, besides co-relating with the resistance to 50 MPa, the total volume of intruding mercury and the critical diameter of the pores. To these analysis perform, prototypes specimens of 75 cm x 20cm x 15cm have been molded with high contents of mineral additions, 70 % of slag and 20% of fly ash, in replacement to the cement mass, with or without addition of 20% of hydrated lime, in mass, and w/cm relationships 0,3 ; 0,4 ; 0,5 besides the reference mix proportion, only with cement and w/cm relationships 0,4; 0,6 e 0,8. The tests of capillary absorption and water diffusion were held, on the 91 and 300 days to execute the comparative study between these two ages, extracted specimens of 10 cm x 20 cm, from the prototypes had been accomplished, being closed to 0, 2,5 e 5,0cm of depth from the surface. After performing the analysis, it has been noticed that the replacement of cement by mineral additions causes a strength reduction to the compression, being it more accentuated in the initial ages and eased as the time passes by. In relation to the coefficients of water absorption and diffusion of the concretes with mineral additions compared to the reference concretes in equality of w/cm and ages, being analyzed the use of additions, meaningful reductions that get to 79% in the absorption and 69% in the diffusion, on the 300 day. When analyzed considering the depth (in equality of w/cm) the layer reduction 3 (5cm) in relation to 1(0,5cm) gets to 55% in the absorption and 31% in the diffusion, on the 300 day, and in the mix proportion with addition of hydrated lime, justifiable by the fact of the hydrated lime stored water helping in the hydrating process producing a more compact matrix. In equality of 50 Mpa compressive strength, the reductions are 86% to the absorption and 70% to the diffusion. It s been noticed, as to the absorption as to the diffusion, a strong co-relation with the intruding total volume and the pores diameter on the 300 day.
O estudo da durabilidade das estruturas de concreto passa, necessariamente, pelo estudo do concreto de cobrimento e pelo entendimento dos fatores que afetam as características dessa camada superficial. O uso de altos teores de adições minerais no concreto influencia significativamente a resistência da camada de cobrimento ao ataque químico e a estrutura dos poros. Esta dissertação tem por objetivo analisar, através dos resultados obtidos nos ensaios de absorção capilar de água, conforme a norma RILEM TC-116 PCD, e de difusão de água, realizado seguindo as diretrizes de Dan et al (1988), apresentadas por Isaia (1995), baseadas em publicações de CSTB, a percolação de água na camada de cobrimento do concreto, além de correlacionar com a resistência a 50 MPa , o volume total de mercúrio intrudido e o diâmetro crítico dos poros. Para realização dessas análises, foram moldadas peças protótipos de 75 cm x 20 cm x 15 cm, que permaneceram em exposição ambiental até a data de realização dos ensaios. Os protótipos foram moldados com altos teores de escória, 70% e cinza volante 20%, em substituição à massa de cimento, com e sem adição de 20% de cal hidratada, em massa, e uma relação a/mc 0,3, 0,4, 0,5, além do traço de referência, somente com cimento e relação a/c 0,4; 0,6 e 0,8. Os ensaios de absorção capilar e de difusão de água foram realizados aos 91 e 300 dias. Para executar o estudo comparativo entre essas duas idades, foram extraídos testemunhos 10 cm x 20 cm dos protótipos sendo cerrados a 0, 2,5 e 5,0 cm de profundidade a partir da superfície. Após a realização das análises, observou-se que a substituição de cimento por adições minerais acarreta uma diminuição na resistência à compressão, sendo mais acentuada nas idades iniciais e amenizada com o passar do tempo. Em relação aos coeficientes de absorção e de difusão de água dos concretos com adições minerais, comparados com os concretos de referência, em igualdade de a/mc e idades analisadas, o uso de adições resultou em significativas reduções nesses coeficientes, que chegam a 79% na absorção e de 69% na difusão, aos 300 dias. Quando analisados em função da profundidade (em igualdade de a/mc), as reduções da camada 3 em relação à camada 1 chegam a 55% na absorção e 31% na difusão, aos 300 dias e nos traços com adição de cal hidratada. Esse comportamento é justificável pelo fato de a cal hidratada armazenar água auxiliando nos processos de hidratação, produzindo uma matriz mais compacta. Em igualdade de resistência, as reduções são de 86% para a absorção e de 70% para a difusão. Observa-se, tanto para a absorção como para a difusão, uma forte correlação com o volume total intrudido e o diâmetro dos poros aos 300 dias.
4
Keil, Allessandra, and Michael Raupach. "Polymermodifizierte Feinbetone - Untersuchungen zum Feuchtetransport." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-77927.
Full textAbstract:
Untersuchungen zur Dauerhaftigkeit von ARGlasbewehrung im Textilbeton haben gezeigt, dass durch die Alkalität des Betons in Verbindung mit Feuchtigkeit eine Glaskorrosion hervorgerufen wird, die im Laufe der Zeit zu Festigkeitsverlusten des Glases führt. Eine Möglichkeit, die durch die Glaskorrosion verursachten Festigkeitsverluste zu reduzieren, stellt die Polymermodifikation des Betons dar. Durch die Polymerzugabe wird die Wasseraufnahme der Feinbetonmatrix reduziert, dadurch sinkt der Gehalt an gelösten Alkalien im Bereich der Bewehrung. Um den Einfluss verschiedener Feinbetonmatrices auf die Dauerhaftigkeit von Textilbeton beurteilen zu können, sind u. a. zeit- und tiefenabhängige Informationen zur Feuchteverteilung erforderlich, die durch den Einsatz der NMR-Technik gewonnen werden. Der nachfolgende Artikel beschreibt den Feuchtetransport in einer speziell für den Textilbeton entwickelten Feinbetonmatrix sowie den Einfluss verschiedener Modifikationsstoffe auf das Wasseraufnahmeverhalten des BetonsDurability tests of textile reinforced concrete revealed a loss of strength of the AR-glass reinforcement due to glass corrosion effected by the alkalinity and moisture content of the concrete. In order to reduce this strength loss of AR-glass in cementitious matrices, polymers can be used for concrete modification. The aim of the polymer addition is to reduce the amount of capillary water absorption of the matrix, which reduces the amount of free alkalies closed to the reinforcement. In order to evaluate the effect of the concrete matrix on the durability of TRC, it is necessary to determine the moisture content as functions of time and depth. This data can be obtained by the use of nuclear magnetic resonance (NMR) technique. This paper deals with the moisture transport in a finegrained concrete matrix especially developed for the use in TRC as well as the influence of polymer addition on the water absorption properties of the concrete matrix
5
Lieboldt, Matthias, and Viktor Mechtcherine. "Medientransport durch Verstärkungsschichten aus textilbewehrtem Beton." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1244045285527-10721.
Full textAbstract:
In den durchgeführten Versuchsreihen wurden die Wasserabsorption sowie die Gas- und Wasserpermeabilität sowohl an gerissenen als auch rissfreien Prüfkörpern aus textilbewehrtem Beton (TRC) untersucht. Eine deutliche Steigerung der Wasseraufnahme bei Proben mit unbeschichteten Textilien konnte mit Zunahme der Garnfeinheit beobachtet werden. Bei den gerissenen Proben besteht eine ausgeprägte Abhängigkeit der Transportraten von Flüssigkeiten und Gasen zu den relevanten Risscharakteristika (kumulative Risslänge, Rissbreite). Weiterhin sind Selbstheilungseffekte von feinen Rissen infolge einer zyklischen Wasserbeaufschlagung beobachtet worden. Hierbei kam es zu einer deutlichen Reduzierung der Transportraten sowohl für Wasser als auch für Gase. Eine speziell entwickelte Permeabilitätsmesskammer zur Durchführung von In- Situ-Messungen ermöglicht Untersuchungen zum Stofftransport unter axialer Zugbelastung bei verschiedenen Dehnungszuständen.
6
Wallqvist, Viveca. "Interactions between non-polar surfaces in water: Fokus on talc, pitch and surface roughness effects." Doctoral thesis, KTH, Ytkemi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10283.
Full textAbstract:
The aim of this thesis work was to gain understanding of the interactions between talc mineral and surfaces, liquids and chemicals relevant for industrial applications, such as pulp and paper. Talc is used in the pulp and paper industry as a filler pigment, in control of pitch (lipophilic extractives) deposits and as a coating pigment. A deeper understanding of talc interactions will be beneficial in optimizing its use. Long-range attractive interactions between talc and hydrophobic model probes, as well as pitch probes, have been measured using the atomic force microscope (AFM) colloidal probe method. Two procedures for preparation of pitch colloidal probes were developed to allow these studies. Model hydrophobic, nanorough surfaces with surface energy characteristics similar to talc have also been prepared and their interactions with hydrophobic model probes compared to interactions between hydrophobic model probes and talc. It is demonstrated that talc mineral interacts with model hydrophobic particles, as well as with pitch, by long-range attractive forces, considerably stronger than the expected van der Waals force. The possible origin of the measured interaction forces is discussed, and the conclusion is that the main cause is an attractive capillary force due to formation of a gas/vapor capillary between the surfaces. Force measurements using model hydrophobic, nanorough surfaces show that a large-scale waviness does not significantly influence the range and magnitude of the capillary attraction, but large local variations in these quantities are found. It is demonstrated that a large variation in adhesion force corresponds to a small variation in local contact angle of the capillaries at the surfaces. The nature of the surface topographical features influences the capillary attraction by affecting the local contact angle and by pinning of the three-phase contact line. The effect is clearly dependent on the size of the surface features and whether they exist in the form of crevices or as extending ridges. Entrapment of air also affects the imbibition of water in pressed talc tablets. The effects of wetting and dispersion agents on the interactions between talc and hydrophobic probes have also been investigated. It is demonstrated that a common dispersing agent used for talc, poly(acrylic acid), does not affect the capillary attraction between talc and non-polar probes. In fact, the results strongly suggest that poly(acrylic acid) does not adsorb on the basal plane of talc. From this finding it is inferred that the stabilizing effect of this additive most likely is due to adsorption to the edges of talc. In contrast, a wetting agent (the non-ionic triblock copolymer Pluronic PE6400) removes the long-range capillary attraction. It is suggested that such an ability to replace air at the talc surface is of great importance for an efficient wetting agent. The Hamaker constant for talc has also been estimated by using optical data obtained from spectroscopic ellipsometry. It is demonstrated that a nanocrystalline talc mineral, cut in different directions displays very small differences in Hamaker constant between the different crystallographic orientations, whereas a microcrystalline sample displays a significantly higher value. The estimated Hamaker constants are discussed for different material combinations of relevance for the pulp- and paper industry, such as cellulose and calcium carbonate.Målet med detta avhandlingsarbete var att öka förståelsen för interaktioner mellan talkmineral och ytor, vätskor och kemikalier relevanta för industriella applikationer, såsom papper och massa. Talk används i pappers- och massaindustrin som fyllmedel, för kontroll av hartsrika (lipofila extraktivämnen) avsättningar och som bestrykningspigment. En djupare förståelse för talkinteraktioner kommer att vara användbart för att optimera dess användning. Långväga attraktiva interaktioner mellan talk och hydrofoba modellpartiklar, såväl som mellan talk och hartspartiklar, har uppmätts med hjälp av atomkraftsmikroskopi (AFM) genom att fästa kolloidala partiklar på kraftsensorn. Två metoder för att framställa partiklar gjorda av harts har utvecklats för att möjliggöra dessa studier. Hydrofoba, nanostrukturerade modellytor med ytenergier liknande de för talk har också tillverkats och deras växelverkan med hydrofoba modellpartiklar har jämförts med dem mellan talk och hydrofoba modellpartiklar. Studierna visar att talkmineral växelverkar med hydrofoba modellpartiklar, såväl som med harts, genom långväga attraktiva krafter som är betydligt starkare än den förväntade van der Waals kraften. Möjliga orsaker till de uppmätta växelverkanskrafterna diskuteras och slutsatsen blir att huvudorsaken är en attraktiv kapillärkraft som uppkommer genom att en gas-/ångkapillär bildas mellan ytorna. Kraftmätningar gjorda med hydrofoba nanostrukturerade modellytor visar att en storskalig vågighet inte nämnvärt påverkar storleken av kapillärattraktionen, men stora lokala variationer existerar. Det demonstreras att en stor variation i adhesionskraft motsvaras av en liten variation i lokal kontaktvinkel för kapillärerna på ytorna. Ytornas topografi påverkar kapillärattraktionen genom att påverka den lokala kontaktvinkeln samt genom att trefaskontaktlinjen inte kan röra sig fritt över ytan. Effekten är tydligt beroende av huruvida ytojämnheterna existerar i form av nedsänkningar eller upphöjningar. Instängd luft påverkar också pressade talktabletters uppsugningsförmåga av vatten. Vätnings- och dispergeringsmedels inverkan på växelverkan mellan talk och hydrofoba partiklar har undersökts. Resultaten visar att ett vanligt dispergeringsmedel för talk, polyakrylsyra, inte påverkar kapillärattraktionen. I själva verket tyder data på att polyakrylsyra inte adsorberas på talks basalplan. Utifrån dessa resultat dras slutsatsen att polyakrylsyra stabiliserar talkdispersioner genom att adsorbera på talkkanterna. Ett vanligt vätmedel (nonjonisk triblock sampolymer Pluronic PE6400) tar å andra sidan bort långväga kapillärattraktion. Detta antyder att egenskapen att ersätta luft på talkytan är av stor betydelse för effektiva vätmedel. Hamakerkonstanten för talk har uppskattats genom att utnyttja optiska data från ellipsometrimätningar. Det demonstreras att ett nanokristallint talkmineral kapat i olika riktningar uppvisar mycket små skillnader i Hamakerkonstant mellan de olika kristallografiska orienteringarna, medan ett mikrokristallint prov uppvisar ett betydligt högre värde. De beräknade Hamakerkonstanterna diskuteras för olika materialkombinationer relevanta för pappersindustrin, såsom cellulosa och kalciumkarbonat.
QC 20100813
7
Skoupil, Jakub. "Vliv etherů celulózy na vlastnosti hydraulického vápna." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392357.
Full textAbstract:
This diploma thesis deals with the study of the influence of cellulose ethers on the properties of hydraulic lime mortars. The availability and price of cellulose ethers in the industrial market is very favorable, but we can´t meet with studies using cellulose ethers in building materials, where lime is used as a binder. Cellulose ethers are commonly used as thickening agents in cement-based materials. The purpose of this diploma thesis is to review if cellulose ethers are appropriate for use in hydraulic lime mortars, either as water retention agents that contribute by water retention to better hydration of hydraulic binder components or to affect the properties of mortar in the fresh state. The theoretical part is dedicated to cellulose ethers, especially their production and how they influence the properties of building materials. In the practical part, the thesis deals with the influence of the dose of five different types of cellulose ethers on the properties of hydraulic lime. The properties in the fresh state and the physical-mechanical properties of mortars were monitored over time.
8
Studencová, Alžběta. "Porovnání hydraulických vlastností kavernózně zvětralých hornin do tvarů tafoni a voštin." Master's thesis, 2017. http://www.nusl.cz/ntk/nusl-369000.
Full textAbstract:
Forms of cavernous weathering - tafoni and honeycombs - belong to long-term investigated and discussed phenomena in geology. The reason for the difference in size between few centimetres- long honeycombs and the several-metres-long tafoni has not been yet studied. In my master thesis I compared the hydraulic properties of rocks with developed honeycombs and tafoni. The research consists of field measurements (measurement of suction pressures and capillary water absorption using Karsten tube) and laboratory measurements on tafoni and honeycomb samples (retention curve measurement, capillary water absorption, water vapour diffusion rate and saturated hydraulic conductivity). I have been studing honeycombs from various sites in the Bohemian Cretaceous Basin and tafoni from three different sites: Carbon Arkoses near Kralupy nad Vltavou, Cambrian Sandstone in Petra (Jordan) and Tunnel Spring Tuff in Crystal Peak (Utah). The measurements showed that values of suction pressure are far higher inside tafoni than inside honeycombs. This observation corresponds to different retention curves of studied rocks: steeper retention curve for honeycomb's quartz sandstone than for fine-grained arkosic sandstones to arkoses with tafoni. In the other part of my research I have compared the properties of hydrophobic...
9
Slavík, Martin. "Propustnost přírodních povrchů hruboskalského pískovce ve skalních městech pro vodní páru a intenzita výparu." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-341321.
Full textAbstract:
Aim of this study was to describe capillary water and vapor transport in shallow subsurface of Hrubá Skála sandstone in the Bohemian Paradise. I have quantified permeability of Hrubá Skála sandstone for water vapor using "wet cup" method and also capillary water absorption of sandstone drill cores. I have found out general rules of evaporation and rate of evaporation from several sandstone outcrops in real microclimate. Important part of my work was to determine whether surface crust plays some role in studied parameters. Based on my results, permeability of different types of sandstones for water vapor does not vary significantly and surface crust has no effect on rate of water vapor diffusion. Rate of capillary water absorption is reduced by surface crust. Hrubá Skála sandstone is classified as medium or highly absorbing material. I have proved that evaporation from porous medium can be approximated by exponential function. Rate of evaporation is strongly controlled by climatic conditions, especially by relative humidity. Powered by TCPDF (www.tcpdf.org)
10
Sysel, Ondřej. "Propustnost pískovcových povrchů a pohyb vody v mělkých zónách skalních měst." Master's thesis, 2020. http://www.nusl.cz/ntk/nusl-435014.
Full textAbstract:
Water in porous rocks (e.g. sandstone) plays a fundamental role in their disintegration. However, the places where water enters the sandstone rocks are somewhat overlooked. At two sites in the Český ráj region, I use Karsten tube to measure capillary water absorption (CWA) of natural sandstone exposures and, using TDR (Time Domain Reflectometry) method, I study movement of water in a shallow zone of ruiniform sandstone landscape. The CWA differed up to four orders of magnitude at a distance of tens of meters, mostly depending on the type of the surface. The highest CWA was measured at highly weathered surfaces, the second most absorbent were less weathered surfaces covered with a biologically-initiated rock crust. The horizontal surfaces on the tops of the rock formations were even less absorbent, probably due to clogging by fine particles from soil. Surfaces covered with iron crust were the least absorbent. The differences between those surfaces are significant. After simulated infiltration, the maximum rate of the propagation of the wet front in the sandstone was from 5,5.10-6 do 1,9.10-4 m.s-1 measured by TDR. The water propagated at this rate only to a certain depth (the first tens of cm), but then the propagation stopped or slowed down rapidly. From a long-term measurement of volumetric...
Book chapters on the topic "Capillary water absorption"
1
Wagner, Christian, Beate Villmann, and Volker Slowik. "Water Permeability and Capillary Absorption of Cracked SHCC." In Strain-Hardening Cement-Based Composites, 591–99. Dordrecht: Springer Netherlands, 2017. http://dx.doi.org/10.1007/978-94-024-1194-2_68.
Full text
2
Mao, Gang. "A Study of Bio-Computational Design in Terms of Enhancing Water Absorption by Method of Bionics Within the Architectural Fields." In Proceedings of the 2021 DigitalFUTURES, 102–13. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-5983-6_10.
Full textAbstract:
AbstractThis essay aims to explore an architecture computational design intended to accept and absorb moisture through geometrical and material conditions, and using design strategies, help deliver this moisture upwards through capillary action to areas of cryptogamic growth including mosses and smaller ferns on the surface of architecture. The purpose of this research project is to explore the morphology of general capillary systems based on research into the principle of xylematic structures in trees, thereby creating a range of capillary designs using three types of material: plaster, 3D print plastic, and concrete. In addition, computational studies are used to examine various types of computational designs of organic structures, such as columns, driven by physical and environmental conditions such as sunshine, shade, tides and other biological processes to explore three-dimensional particle-based branching systems that define both structural and water delivery paths.
3
Ren, Fangzhou, and Chunsheng Zhou & WeiWang. "Modeling capillary absorption of water in cement-based materials with time-dependent permeability." In Life-Cycle Civil Engineering: Innovation, Theory and Practice, 754–59. CRC Press, 2021. http://dx.doi.org/10.1201/9780429343292-99.
Full text
4
Warrick, Arthur W. "One-Dimensional Absorption." In Soil Water Dynamics. Oxford University Press, 2003. http://dx.doi.org/10.1093/oso/9780195126051.003.0009.
Full textAbstract:
In this chapter we address one-dimensional absorption. Absorption denotes movement of water (or other liquid) into a soil under the influence of capillarity without the effects of gravity. Although important for horizontal flow conditions, there is more interest in the results and principles relevant to the early stage of infiltration and in general relationships descriptive of the physical principles for all unsaturated systems. At the outset, two simplified systems will be considered. Included is the classical problem of linear diffusion into a semi-infinite domain. Then the Boltzmann similarity transform will be applied, confirming results from the simplified solutions and leading to methods for finding soil-water diffusivity and Philip’s quasi-analytical solution. Finally, simultaneous water flow will be considered as a two-phase process. Figure 4-1 shows water introduced into a horizontal column of soil at a matric potential hwet. The value of hwet is maintained as zero or negative by the “mariotte” device to the left. The initial condition is that the matric potential is hdry with hdry < hwet ≤ 0. A porous plate at x = 0 allows water to come into the system but prevents air from flowing from the soil back into the water supply. The right-hand end allows air to freely escape the system as the water displaces the air. Vertical movement in the soil column is ignored. We make key simplifying assumptions that the conductivity is a constant K = Kwet in the wet part of the column and K = 0 for the dry part. Furthermore, we assume a sharp division between the wet and dry part at xf. On the supply side of the column (0 < x < xf), the water content is a constant (θ = θwet) and, to the dry side, the initial value is maintained (θ = θdry). These are equivalent to the “Green–Ampt” assumptions used in chapter 5, when gravity will be included as a driving force.
Conference papers on the topic "Capillary water absorption"
1
Alberghina, M. F., R. Barraco, M. Brai, A. Lo Casto, A. Mazzocchio, and T. Schillaci. "X-ray CT imaging as a scientific tool to study the capillary water absorption in sedimentary rocks used in cultural heritages." In SPIE Europe Optical Metrology, edited by Luca Pezzati and Renzo Salimbeni. SPIE, 2009. http://dx.doi.org/10.1117/12.827745.
Full text
2
Zhang, P., T. J. Zhao, L. S. Zhang, F. H. Wittmann, E. Lehmann, and P. Vontobel. "Application of Neutron Radiography to Observe Water Absorbtion of Concrete." In 18th International Conference on Nuclear Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/icone18-29080.
Full textAbstract:
It has been experienced that service life of reinforced concrete structures is often limited due to lack of durability of cement-based materials. One major reason for this durability problem is the penetration of water and compounds dissolved in water into concrete. Therefore, there is an urgent need to study water penetration into concrete in order to better understand deterioration mechanisms. Neutron radiography provides an advanced non-destructive technique with high spatial resolution. In this contribution, neutron radiography was successfully utilized to study the process of water absorption of two types of concrete with different water-cement ratios namely 0.4 and 0.6. It is shown that it is possible to visualize migration of water into concrete and to quantify the time-dependent moisture distribution with accurately and with high spatial resolution by means of neutron radiography. In concrete with high water-cement ratio, water penetrates much quicker than in concrete with lower water cement ratio. Water penetration depth obtained from neutron radiography is in good agreement with corresponding values obtained from capillary suction tests. Experimental results obtained by means of neutron radiography on water penetration into concrete will be presented and discussed in this contribution. Results will provide us with a solid basis for a better understanding of deteriorating processes in concrete and other cement-based materials. These results may be considered to be a first step to improve durability of concrete.
3
Suciu, Claudiu Valentin. "Thermal Effects on Nano-Energy Absorption Systems (Nano-EAS)." In 2008 Second International Conference on Integration and Commercialization of Micro and Nanosystems. ASMEDC, 2008. http://dx.doi.org/10.1115/micronano2008-70039.
Full textAbstract:
Development of intelligent and ecological energy absorption systems (EAS) is important to various fields such as automotive (vehicle suspensions, bumpers, engine mounts), construction (protections against seismic and wind-induced vibrations), and defense (parachuted objects, armors). Usual EAS use composites, shape-memory alloys and foams. Recently, liquid adsorption/desorption in/from nanoporous solids was employed to develop high-performance nano-EAS. Energy loss is based on the well-known capillary phenomenon: external work must be done to spread a non-wetting liquid on a solid surface. Nano-EAS provide considerably higher dissipated energies, about 1–10J/g at deformability of 30–70%, compared with the energy absorption of Ti-Ni alloys, about 0.01–0.05J/g at deformability of 5–8%. For water against hydrophobic nanoporous silica gel (artificial sand), the nano-EAS become ecological; they can be also made intelligent by thermo-electrical control. Relative to thermal effects, Qiao et al. have investigated, for nanoporous silica gel with insufficient coverage of the alkyl-based hydrophobic coating, the problem of hysteresis recovery by increasing the temperature in the range 20∼80°C. Energy loss capacity reduced severely after the first loading-unloading cycle, so, the hysteresis was found as irreversible. Shape of the first hysteresis, the accessible specific pore volume and the desorption pressure were almost unaffected by the temperature change. At temperature augmentation the second hysteresis was partially recovered and when the temperature exceeded 50°C the system became almost fully reusable. Water inflow was found as governed by Laplace-Washburn equation but the outflow process was perceived as thermally aided. On the other hand, Eroshenko et al. have contradictorily obtained for nanoporous silica gel with full coverage of the alkyl-based hydrophobic coating, a stable hysteresis at repeated working cycles. Adsorption pressure decreased and desorption pressure increased at temperature augmentation, this producing a reduction of the hysteresis area and damping. However, the accessible specific pore volume was found as thermally unaffected. Oppositely, both the in- and out-flows were found as governed by Laplace-Washburn equation. In this work, for nanoporous silica gels with partial and full coverage of the alkyl and fluorocarbon based hydrophobic coatings, the thermal effects on the hysteresis and damping performances are studied. Test rig used is a compression-decompression chamber introduced inside of an incubator that allows temperature adjustment in the range of −10∼50°C. Results reveal that, depending on the hydrophobic coating coverage, findings reported by Qiao et al. and Eroshenko et al. are in fact not contradictory but complementary. However, as expected, the accessible specific pore volume was found to decrease at temperature reduction. In order to explain all these apparently opposite experimental findings, a model based on the water cluster size distribution versus temperature, the pore size distribution of silica gel and the ability of water molecules to form hydrogen bonds with the uncovered hydroxyl groups on the solid surface is proposed.
4
Namsone, Eva, Genadijs Sahmenko, Elvija Namsone, Endija Namsone, Aleksandrs Korjakins, and Diana Bajare. "Experimental investigation on foamed concrete produced using a planetary ball mill." In The 13th international scientific conference “Modern Building Materials, Structures and Techniques”. Vilnius Gediminas Technical University, 2019. http://dx.doi.org/10.3846/mbmst.2019.152.
Full textAbstract:
The experimental study is devoted to investigation on foamed concrete produced applying innovative intensive mixing technology by using a planetary ball mill. Modern type of foamed concrete represents cementitious composite material group which may be competitive with traditionally used autoclaved aerated concrete. Innovative mixing method makes possible stabilizing of foamed concrete mixture and improving the microstructure of material. The aim of this study is to investigate physical and mechanical properties of non-autoclaved concrete such as density and compressive strength, and capillary water absorption depending on intensive mixing time. In this research microstructure, such as pore size diameters, depending on mixing time is also analysed.
5
Sohawon, Haris, and Hans Beushausen. "The effect of hydrophobic impregnation on chloride ingress into cracked concrete." In IABSE Congress, New York, New York 2019: The Evolving Metropolis. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2019. http://dx.doi.org/10.2749/newyork.2019.1963.
Full textAbstract:
<p>Premature concrete degradation due to rebar corrosion has many financial and social implications on a large scale. Direct costs relate to the repair and rehabilitation of existing structures to maintain serviceability while indirect costs include loss in productivity and reduced economic growth. Hydrophobic (silane) impregnation represents a cost-effective way to increase the durability of concrete structures in cases where insufficient design cover quality and depth have been achieved. The water repellent product lines the internal capillary pore structure and provides a water-repellent concrete surface. Thus, the risk of reinforcement corrosion initiation and subsequent deterioration can be reduced as the ingress of water-dissolved aggressive species (chlorides) is minimised or prevented. The purpose of this study was to investigate and quantify the influence of silane impregnation as a remedial measure for poor quality or insufficient cover depth in newly constructed structures and ultimately predict the service life extension possible for specific cover depths. The effectiveness of silane impregnation in cracked concrete was also studied. The results indicate that silane impregnation reduces capillary absorption and conductivity of chloride ions for all the mixes. Chloride ingress in the treated concrete mixes was suppressed and lower chloride surface concentration (C<sub>s</sub> and apparent chloride diffusion coefficient (D<sub>a</sub>) were recorded. A slight decrease in carbonation depth was observed in the w/b 0.60 concrete mixes. The results also suggest that silane impregnation reduces chloride ingress in cracked concrete (up to a crack width of 0.6 mm). A lower rate of chloride ingress was predicted in the silane treated concrete and consequently to achieve the same service life, smaller cover depths are required. The overall results indicate that the service life of concrete with inadequate cover depth and quality, regardless of the binder type, can be effectively extended using hydrophobic (silane) impregnation, assuming proper surface preparation and application methods.</p>
6
Khanolkar, Ratnesh U., and A. K. Suresh. "Effect of Material of Nanoparticle on Mass Transfer Enhancement and a Convective Diffusion Model to Predict the Enhancement." In ASME 2013 4th International Conference on Micro/Nanoscale Heat and Mass Transfer. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/mnhmt2013-22178.
Full textAbstract:
While particles smaller than the thickness of the diffusion film have been known to enhance rates of interfacial mass transfer [1], a relatively new result is the discovery that nanoparticles in suspension show enhancements that far exceed the earlier reported enhancements, and without any apparent adsorptive or reactive effects[2]. Different mechanisms for the enhancements have been speculated upon, but there is a paucity of data on different nanoparticulate materials, collected in a systematic way on model contactors so that rational comparisons may be made. In this work, enhancement in Carbon dioxide absorption in water has been studied using SiO2 and TiO2 nanoparticles using the same capillary tube apparatus for which previous results of Fe3O4 were reported. For 0.4% silica particles and 0.0118% TiO2 nanoparticles, 165% and 155% enhancement was observed respectively. A phenomenological convective diffusion model has been proposed to explain the observed effects of particle size, holdup and material density. The model accounts for the overall effect of the Brownian (and any diffusiophoretic) motion of the nanoparticles on the surrounding fluid in terms of an ‘effective’ convective velocity, which is determined from the experimental data and correlated to the modified Sherwood Number proposed earlier [2], volume fraction of Nanoparticles and a solid Reynolds number Rp. This model provides a good fit to the data from wetted wall column and capillary tube experiment for iron oxide from the previous literature, as well as for the data on silica and Titanium dioxide nanoparticles from this work, the average error being 8.3%.
7
Shrestha, S., A. Hays, S. Thapa, D. Wood, D. Bailey, and L. Weiss. "Small-Scale Thermal Energy Harvester With Copper Foams and Thermal Energy Storage." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-52406.
Full textAbstract:
This article investigates the use of advanced, high porosity thermally conductive foams and a thermal energy storage (TES) device for small scale thermal energy harvesting. In final application, it may be employed in various real world situations that include existing systems like thermoelectric generators (TEGs) and thermal scavenging systems that provide power output from freely available thermal sources. Experimental tests were conducted using various porosity metallic copper foams ranging from 85 % to 89 % porosity. Copper foams were selected to serve as the heat exchanger innards and examined for several key attributes. These included the ability of the foams to yield capillary action with working fluids like water or 3M™ HFE7200. Thermal energy absorption by the exchanger to the working fluid was also monitored. These results were compared to other exchangers based on capillary channel fabrication techniques as previously reported by the research team. Full characterization was based on operating temperature, measured thermal input, mass transfer rate, and heat transfer capability. Preliminary investigation of a matching, small-scale TES unit designed to integrate with the heat exchanger and a future thermoelectric for energy harvesting application was also conducted. Thermal storage was accomplished via solid-liquid phase change of a paraffin wax within the TES device forming a so-called “thermal battery.” In a final design, the TES includes what is defined by thermodynamics as heat pipes. The integrations of several heat pipes, made of copper tubing and filled with working fluid, mounted vertically and immersed in the wax medium will transfer heat to the wax by means of thermal conductivity and phase transition. This represents a first of its kind in this small-scale, thermal harvesting application. The specific tests performed in this initial work included one TES unit filled with a paraffin wax medium and a second that contained several copper vertically placed tubes surrounded by the paraffin wax. The overall thermal conductivity of the phase change medium (wax) was investigated for both constructions as was the ability of each to absorb thermal energy directly. Results indicated capillary action of the working fluid was possible via incorporation of copper foams within the heat exchanger. Maximum heat flux observed in exchanger tests was 0.27 kW/m2 given an operating temperature of 76.6 °C and 2.5W thermal input. Thermal storage tests indicated a maximum thermal capture rate of 0.91 W and phase change material thermal conductivity of 1.00 W/mK for the TES device constructed with copper tubing innards. This compared favorably to the baseline wax conductivity of approximately 0.32 W/mK. Future efforts will fully incorporate both the heat exchanger and matching TES device for a complete harvesting and thermal capture system. The ability of the exchanger to provide thermal energy for storage to the “thermal battery” will be monitored.