Physical and mechanical properties of the repaired sandstone ashlars in the facing masonry of the Charles Bridge in Prague (Czech Republic) and an analytical study for the causes of its rapid decay

2010 ◽  
Vol 63 (7-8) ◽  
pp. 1623-1639 ◽  
Author(s):  
Richard Přikryl ◽  
Zuzana Weishauptová ◽  
Miroslava Novotná ◽  
Jiřina Přikrylová ◽  
Aneta Št’astná
Keyword(s):  
Mechanical Properties ◽  
Czech Republic ◽  
Analytical Study ◽  
Physical And Mechanical Properties ◽  
Rapid Decay

Testing and Optimization of Production of Technical Foam for the Production of Cement Foam

2018 ◽  
Vol 276 ◽  
pp. 254-258
Author(s):  
Karel Mikulica ◽  
Dušan Dolák
Keyword(s):  
Mechanical Properties ◽  
Czech Republic ◽  
Construction Industry ◽  
Building Materials ◽  
Cement Mortar ◽  
Physical And Mechanical Properties ◽  
Foam Concrete ◽  
The Czech Republic ◽  
Insulation Materials ◽  
The Many

In the current construction industry, great importance is given to the usage of thermally insulating building materials. One of the many such materials can be a cement foam or foam concrete, a mixture of cement mortar and technical foam. This material can be, due to its consistency right after mixing, applied to uneven horizontal surfaces where usage of conventional thermal board insulation materials would be complicated. This paper discusses the methodology of testing of the physical and mechanical properties of foaming additives such as strength, density, foaming number and half-separability of technical foams. Then this methodology was subsequently verified on the five commonly used foaming additives in the Czech Republic.

scholarly journals Physical and mechanical properties of subfossil oak (Quercus, sp.) wood

2010 ◽  
Vol 58 (4) ◽  
pp. 123-134 ◽  
Author(s):  
Tomáš Kolář ◽  
Michal Rybníček
Keyword(s):  
Mechanical Properties ◽  
Czech Republic ◽  
Radiocarbon Dating ◽  
Physical And Mechanical Properties ◽  
Wood Properties ◽  
The Other ◽  
The Czech Republic ◽  
Oak Wood ◽  
Gravel Pit ◽  
Subfossil Wood

The paper deals with the examination of physical and mechanical properties of subfossil wood of oak (Quercus, sp.). The issue of establishing physical and mechanical properties of subfossil oak wood has not yet been addressed in the area of the Czech Republic. The main objective is to find out what changes to subfossil wood properties have occurred in comparison with recent wood. For these purposes, samples from three locations were taken (gravel pit Tovačov – district Přerov, gravel pit Kostomlátky – district Nymburk, and the Bečva basin near Osek nad Bečvou). All of the selected properties were tested in compliance with relevant valid Czech technical norms (ČSN). The results provide us with a realistic picture of the properties of wood that has been deposited under the ground in very specific conditions for thousands of years. With regard to density, the results do not show any definite changes. The dimensions of subfossil wood are approximately doubled in comparison with recent wood. On the other hand, there is an obvious decrease in mechanical properties. The paper also offers the results of dendrochronological or radiocarbon dating of the trunks.

Analysis of Alkali Oxides Influence on the Microstructure of Refractory Grog

2021 ◽  
Vol 325 ◽  
pp. 188-193
Author(s):  
Lenka Nevřivová ◽  
David Zemánek
Keyword(s):  
Mechanical Properties ◽  
Czech Republic ◽  
Experimental Work ◽  
Raw Materials ◽  
Physical And Mechanical Properties ◽  
Special Kind ◽  
Alumina Content ◽  
Refractory Materials ◽  
The Czech Republic ◽  
Alkali Oxides

The development and subsequent production of these special kind of grog from raw materials available in the Czech Republic is one of the possibilities how to reduce income costs for the production of refractory materials with specific properties. The experimental work is focused on verifying the possibility of producing grog with increased alumina content from available raw materials. The raw materials are kaolins and claystones. To achieve a higher content of alumina in the grog, waste mullite dust is used. In order to improve the physical and mechanical properties of the grog, modifiers are used. Selected modifiers are expected to affect positively on the resulting density while maintaining the heat properties.

PEMANFAATAN KAYU AKASIA MANGIUM (Acacia mangium Willd) UNTUK MEBEL

2012 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Djoko Purwanto
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physical Properties ◽  
Treatment Process ◽  
Acacia Mangium ◽  
Physical And Mechanical Properties ◽  
Wood Fibers ◽  
Test Parameters ◽  
Mechanical And Physical Properties ◽  
Scale Scores

Timber Acacia mangium (Acacia mangium, Willd) for Furniture. The study aims to determine the mechanical and physical properties and the decorative value (color and fiber) wood of acacia mangium with using finishing materials. This type of finishing material used is ultran lasur natural dof ,ultran lasur classic teak, aqua politur clear dof, aqua politur akasia dan aqua politur cherry. After finishing the wood is stored for 3 months. Test parameters were observed, namely, physical and mechanical properties of wood, adhesion of finishing materials, color and appearance of the fiber, and timber dimensions expansion. The results showed that the mechanical physical properties of acacia wood qualified SNI. 01-0608-89 about the physical and mechanical properties of wood for furniture, air dry the moisture content from 13.78 to 14.89%, flexural strength from 509.25 to 680.50 kg/cm2, and compressive strength parallel to fiber 342.1 - 412.9 kg/cm2. Finishing the treatment process using five types of finishing materials can increase the decorative value (color and fiber) wood. Before finishing the process of acacia mangium wood has the appearance of colors and fibers and less attractive (scale scores 2-3), after finishing acacia wood fibers have the appearance of colors and interesting and very interesting (scale 4-5).Keywords: mangium wood, mechanical properties, decorative value, finishing, furniture.

Physical and Mechanical Properties of Tenun Pahang Fabrics using Alternative Yarns

2016 ◽  
Vol 13 (2) ◽  
pp. 67
Author(s):  
Engku Liyana Zafirah Engku Mohd Suhaimi ◽  
Jamil Salleh ◽  
Suzaini Abd Ghani ◽  
Mohamad Faizul Yahya ◽  
Mohd Rozi Ahmad
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
The Other ◽  
Silk Fabrics ◽  
Recovery Angle ◽  
Made In

An investigation on the properties of Tenun Pahang fabric performances using alternative yarns was conducted. The studies were made in order to evaluate whether the Tenun Pahang fabric could be produced economically and at the same time maintain the fabric quality. Traditional Tenun Pahang fabric uses silk for both warp and weft. For this project, two alternative yarns were used which were bamboo and modal, which were a little lower in cost compared to silk. These yarns were woven with two variations, one with the yarns as weft only while maintaining the silk warp and the other with both warp and weft using the alternative yarns. Four (4) physical testings and three (3) mechanical testings conducted on the fabric samples. The fabric samples were evaluated including weight, thickness, thread density, crease recovery angle, stiffness and drapability. The results show that modal/silk and bamboo silk fabrics are comparable in terms of stiffness and drapability, hence they have the potential to replace 100% silk Tenun Pahang.

Basic set of experiments for determination of mechanical properties of sand

2014 ◽  
Vol 62 (1) ◽  
pp. 129-137
Author(s):  
A. Sawicki ◽  
J. Mierczyński
Keyword(s):  
Mechanical Properties ◽  
Soil Mechanics ◽  
Physical And Mechanical Properties ◽  
Local Strain ◽  
Initial State ◽  
Laboratory Equipment ◽  
Additional Information ◽  
Basic Set ◽  
Initial Anisotropy

Abstract A basic set of experiments for the determination of mechanical properties of sands is described. This includes the determination of basic physical and mechanical properties, as conventionally applied in soil mechanics, as well as some additional experiments, which provide further information on mechanical properties of granular soils. These additional experiments allow for determination of steady state and instability lines, stress-strain relations for isotropic loading and pure shearing, and simple cyclic shearing tests. Unconventional oedometric experiments are also presented. Necessary laboratory equipment is described, which includes a triaxial apparatus equipped with local strain gauges, an oedometer capable of measuring lateral stresses and a simple cyclic shearing apparatus. The above experiments provide additional information on soil’s properties, which is useful in studying the following phenomena: pre-failure deformations of sand including cyclic loading compaction, pore-pressure generation and liquefaction, both static and caused by cyclic loadings, the effect of sand initial anisotropy and various instabilities. An important feature of the experiments described is that they make it possible to determine the initial state of sand, defined as either contractive or dilative. Experimental results for the “Gdynia” model sand are shown.

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