scholarly journals Relationship among the firing temperature, wetting properties and colonization of fungi on clay roofing tile surfaces

2011 ◽  
pp. 197-207
Author(s):  
Jonjaua Ranogajec ◽  
Sinisa Markov ◽  
Ognjen Rudic ◽  
Snezana Vucetic ◽  
Vilma Ducman
Keyword(s):  
Water Absorption ◽  
Firing Temperature ◽  
Surface Characteristics ◽  
Surface Phenomenon ◽  
Experimental Investigations ◽  
Surface Wetting ◽  
Wetting Properties ◽  
Deterioration Process ◽  
Two Temperatures ◽  
Two Stages

The wettability of clay roofing tiles as a surface phenomenon plays a key role considering their deterioration process during exploitation. The experimental investigations in this paper were performed combining the data of the material-relevant parameters and the surface wetting properties in order to assess clay roofing tiles biodurability. The fungus Aspergillusniger was used as a model microorganism whose colonization and growth, during a period of 28 days on the tiles fired at two temperatures (900 and 1020?C), was analyzed. The paper confirms that the colonization of the tiles with the fungus goes through two stages: up to the 18th day, based on the surface characteristics, and after the 18th day when the textural characteristics (values of water absorption) are the dominant parameters.

scholarly journals Effects of Anti-Graffiti Protection on Concrete Durability

2014 ◽  
Vol 634 ◽  
pp. 517-526 ◽  
Author(s):  
Elsa Neto ◽  
Ana Souto ◽  
Aires Camões ◽  
Arlindo Begonha ◽  
Paulo Cachim
Keyword(s):  
Water Absorption ◽  
Atmospheric Pressure ◽  
Surface Characteristics ◽  
Concrete Surface ◽  
Experimental Program ◽  
Concrete Durability ◽  
Protection Systems ◽  
Before And After ◽  
Paint Removal ◽  
Durability Of Concrete

The heritage of fair-faced concrete, largely built in the twentieth century and nowadays recognized as heritage to be protected, is susceptible to attacks by graffiti, a form of vandalism that causes a major social and economic impact on society. Concrete is a porous material sometimes deteriorated over the years, and the interactions between the inks and the substrate and removal methods sometimes deteriorate or alter the concrete surface, especially if it is necessary to repeat the removal process. The anti-graffiti products are applied on the surface of the concrete, hindering the adhesion of paints or preventing its penetration into the pores of concrete, which in turn facilitates their removal. However, it appears that many of the existing protective products on the market may also alter the surface characteristics of the concrete irreversibly. Considering that the durability of concrete depends on the composition and characteristics of the surface, it is essential to know the effects of anti-graffiti protection systems on the durability of concrete and adopt the appropriate methodology to preserve this heritage. Thus, an experimental program was developed for analyzing changes in durability indicators and surface properties that protect concrete from deterioration (i) concrete without protection before and after application of spray paint, (ii) concrete with protection before and after application of spray paint and (iii) after paint removal were studied. Two anti-graffiti products were evaluated: a permanent and a sacrificial one. Effects of the anti-graffiti systems on the concrete durability are investigated and the tests performed include: water absorption by capillary and immersion at atmospheric pressure. The results of the water absorption tests show that the graffiti protection reduces the water absorption into the concrete and facilitates the removal of the graffiti without affecting negatively the characteristics of the surface and thus contributing to improve its durability.

scholarly journals Capillary transfer of soft films

2020 ◽  
Vol 117 (10) ◽  
pp. 5210-5216 ◽  
Author(s):  
Yue Zhang ◽  
Mengtian Yin ◽  
Yongmin Baek ◽  
Kyusang Lee ◽  
Giovanni Zangari ◽  
...  
Keyword(s):  
High Speed ◽  
Computational Analysis ◽  
Liquid Surface ◽  
Theoretical Models ◽  
Dynamic Contact ◽  
Surface Wetting ◽  
Motion Direction ◽  
Wetting Properties ◽  
Geometric Patterns ◽  
Solid Substrates

Existing transfer technologies in the construction of film-based electronics and devices are deeply established in the framework of native solid substrates. Here, we report a capillary approach that enables a fast, robust, and reliable transfer of soft films from liquid in a defect-free manner. This capillary transfer is underpinned by the transfer front of dynamic contact among receiver substrate, liquid, and film, and can be well controlled by a selectable motion direction of receiver substrates at a high speed. We demonstrate in extensive experiments, together with theoretical models and computational analysis, the robust capabilities of the capillary transfer using a versatile set of soft films with a broad material diversity of both film and liquid, surface-wetting properties, and complex geometric patterns of soft films onto various solid substrates in a deterministic manner.

scholarly journals Wetting ofAl2O3by Molten Aluminum: The Influence ofBaSO4Additions

2008 ◽  
Vol 2008 ◽  
pp. 1-12 ◽  
Author(s):  
Joaquin Aguilar-Santillan
Keyword(s):  
High Temperatures ◽  
Firing Temperature ◽  
Molten Aluminum ◽  
Sessile Drop ◽  
Contact Angles ◽  
Sessile Drop Technique ◽  
Pure Alumina ◽  
Two Temperatures ◽  
Drop Technique

The effects ofBaSO4additions on the wetting of alumina by molten aluminum were studied by the sessile drop technique. To study the effect ofBaSO4decomposition(1100–1150∘C), the additions were treated at two temperatures700∘C(973 K) and1450∘C(1723 K), respectively.BaSO4additions at low and high temperatures did not improve the nonwetting character of these compositions. However, at higher firing temperature, the formation ofBA6 (BaO•6Al2O3)has a nonwetting trend with increasing its content. To address theBA6specifically a pureBaO•6Al2O3was produced and tested. It was more nonwetting than the pure alumina. After the analysis of the contact angles for theBaSO4and theBA6 (BaO•6Al2O3), it was concluded that these additions to alumina do not inhibit wetting by molten aluminum. In fact, at the addition levels common for refractories, the wetting tendency of molten aluminum is enhanced. Alternative explanations for the effectiveness ofBaSO4additions to alumina refractories are discussed.

Mechanical Properties and Thermal Conductivity of Lightweight Clay Bricks Fabricated with a Powdered Marble Dust Additive

2018 ◽  
Vol 777 ◽  
pp. 465-470
Author(s):  
Sutas Janbuala ◽  
Mana Eambua ◽  
Arpapan Satayavibul ◽  
Watcharakhon Nethan
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Water Absorption ◽  
Bulk Density ◽  
Firing Temperature ◽  
Apparent Porosity ◽  
Clay Brick ◽  
Clay Bricks ◽  
Marble Dust

The objective of this study was to recycle powdered marble dust to improve mechanical properties and thermal conductivity of lightweight clay bricks. Varying amounts of powdered marble dust (10, 20, 30, and 40 vol.%) were added to a lightweight clay brick at the firing temperatures of 900, 1000, and 1100 °C. When higher quantities of powdered marble dust were added, the values of porosity and water absorption increased while those of thermal conductivity and bulk density decreased. The decrease in apparent porosity and water absorption were also affected by the increase in firing temperature. The most desirable properties of the clay bricks were obtained for the powdered marble dust content of 40 vol.% and firing temperature 900 °C: bulk density of 1.20 g/cm3, compressive strength 9.2 MPa, thermal conductivity 0.32 W/m.K, and water absorption 22.5%.

scholarly journals Modifying hydrophilic properties of polyurethane acryl paint substrates by atomic layer deposition and self-assembled monolayers

RSC Advances ◽  
2020 ◽  
Vol 10 (57) ◽  
pp. 34333-34343
Author(s):  
D. Beitner ◽  
I. Polishchuk ◽  
E. Asulin ◽  
B. Pokroy
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Self Assembled Monolayers ◽  
Surface Wetting ◽  
Wetting Properties ◽  
Layer Deposition ◽  
Assembled Monolayers ◽  
Self Assembled

A process of atomic layer deposition (ALD) combined with self-assembled monolayers (SAMs) was used to investigate the possible modification of polyurethane (PUR) paint surface wetting properties without altering their original hue.

The Effect of Steel Slag Coarse Aggregate on the Mechanical and Durability Performances of Concrete

2020 ◽  
Vol 833 ◽  
pp. 228-232
Author(s):  
Md. Jihad Miah ◽  
Mohammad Shamim Miah ◽  
Anisa Sultana ◽  
Taukir Ahmed Shamim ◽  
Md Ashraful Alom
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Water Absorption ◽  
Coarse Aggregate ◽  
Steel Slag ◽  
Experimental Investigations ◽  
Clay Brick ◽  
Crushing Strength ◽  
Burnt Clay ◽  
Good Agreement

This work performs experimental investigations on concrete made with difference replacement percentage of first-class burnt clay brick aggregate (0, 10, 20, 30, 40, 50, 60, 80, and 100%) by steel slag (SS) aggregate. The aim is to evaluate the mechanical properties as well as durability performances, additionally, water absorption porosity test is performed to investigate the influence of steel slag aggregate on the durability of tested concrete. The experimental results have shown that the compressive strength was improved significantly due to the replacement of brick aggregate by steel slag aggregate. The crushing strength of concrete made with 100% steel slag aggregate has gained up to 70% more than the control concrete (100% brick aggregate). However, the porosity of concrete was reduced with the adding percentage of brick aggregate by steel slag aggregate which is consistent with the compressive strength results. Further, a quite good agreement between compressive strength and porosity was observed as well.

Effect of Firing Temperature on Mechanical and Physical Properties of Porcelain Balls as Grinding Media

2017 ◽  
Vol 888 ◽  
pp. 37-41
Author(s):  
Hasrul Yahya ◽  
Mohd Roslee Othman ◽  
Zainal Arifin Ahmad
Keyword(s):  
Compressive Strength ◽  
Physical Properties ◽  
Water Absorption ◽  
Firing Temperature ◽  
Chemical Resistance ◽  
Firing Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grinding Media ◽  
Mechanical And Physical Properties

Porcelain balls as grinding media are produced by firing process of clay, quartz and feldspar mixtures. This application need high technological properties such as high compressive strength and hardness, wear resistance, low water absorption and excellent chemical resistance. These properties are associated with higher firing temperatures. The porcelain balls were prepared by mixing 30 wt.% clay, 40 wt.% feldspar and 30 wt.% quartz. The samples were sintered at 1200°C, 1230°C, 1250°C, 1270°C and 1300°C for 2 hours with heating rate of 3°C/min. Both green powder and fired samples were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF) and scanning electron microscopy (SEM).The properties of the fired samples were evaluated by compressive strength, hardness, shrinkage, water absorption, bulk density, and porosity measurement. Increasing of compressive strength, hardness and density are associated with increasing of firing temperatures. Porcelain balls PB1 and PB2 can be produced as grinding media with optimum mechanical and physical properties at firing temperature 1270°C and 1250°C, respectively.

Properties of Dan Kwian, Sukhothai and Ratchaburi Pottery Clays Fired at 700 and 900 °C

2014 ◽  
Vol 608 ◽  
pp. 47-61
Author(s):  
Nonglak Meethong ◽  
Wanwisa Pattanasiriwisawa ◽  
Weenawan Somphon ◽  
Waraporn Tanthanuch ◽  
Sutham Srilomsak
Keyword(s):  
Specific Gravity ◽  
Comparative Study ◽  
Water Absorption ◽  
Bulk Density ◽  
Firing Temperature ◽  
Reflectance Spectra ◽  
Modulus Of Rupture ◽  
Regression Equations ◽  
Statistical Software

Dan Kwian, Sukhothai and Ratchaburi pottery clays are economically important pottery clays. They are well known in the Thai ceramic society for making Dan Kwian pottery, Sawankhalok pottery and Dragon jars, respectively. There have been several studies of these pottery clays. However, few of them used statistics to analyze their results. This work is a comparative study of the compositions and properties of these three pottery clays using statistical software to analyze the results. Results show that the major components of these pottery clays are SiO2 and Al2O3. The Modulus of Rupture (MOR) of each pottery clay fired at 700°C are not significantly different. Sukhothai pottery clay fired at 900°C has a higher MOR and bulk density while its porosity, water absorption and apparent specific gravity are less than those of the Dan Kwian and Ratchaburi pottery clays fired at the same temperature. Additionally, the current study developed regression equations for estimating the properties of all pottery clays under study. Finally, it was found that the L*, a*, b* and reflectance spectra of all pottery clays increased when firing temperature was increased from 700 to 900°C.

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