Effect of Freeze/Thaw Cycles on the Physical Properties of Selected Building Stones

2014 ◽  
Vol 1035 ◽  
pp. 83-88
Author(s):  
Zbyšek Pavlík ◽  
Jan Fořt ◽  
Milena Pavlíková ◽  
Jaromír Žumár ◽  
Robert Černý

Effect of climatic loading on the physical properties of three different kinds of sandstone is investigated. The studied materials were used for masonry and ornamental parts of historical buildings over a long time period.The application of sandstone for building construction in the Central European region can be traced to the 14th century and ends in the 19th century, where the static function took over reinforced concrete. The samples of researched sandstones are exposed to the freeze/thaw cycles and the effect on materials performance is evaluated using measurement of several physical parameters. On the basis of obtained results, the materials behavior at real service conditions can be assessed, which is a necessary information for their practical usage in the reconstruction works on the historical monuments.

2015 ◽  
Vol 719-720 ◽  
pp. 210-213 ◽  
Author(s):  
Zbyšek Pavlík ◽  
Jan Fořt ◽  
Milena Pavlíková ◽  
Robert Černý

In reconstruction works on historical buildings, considerable expenses are spent. Therefore, it is desirable to assess durability of applied materials in the particular conditions of a specific building. This cannot be done effectively without the knowledge of their basic physical and hygric properties, which give information on materials performance within their exposure to harmful climatic conditions. In this paper, experimental analysis of five types of sandstone originally used over the Czech territory for historical buildings, monuments and ornamental parts of architecture, is presented. On the basis of obtained results, the materials behavior at real service conditions can be assessed, which is necessary information for their practical usage.


Alloy Digest ◽  
2003 ◽  
Vol 52 (1) ◽  

Abstract Wieland-B18 is a phosphor bronze with a composition that allows usage in slightly more severe service conditions than alloy B16 (UNS C52100). A common application is in slide bearings and slideways. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: CU-696. Producer or source: Wieland Metals Inc., Wieland-Werke AG.


2020 ◽  
Vol 1 (1) ◽  
pp. 19-23
Author(s):  
Diah Willis L ◽  
Thomas Priyasmanu ◽  
Wahyu Panji A ◽  
D. H. Praswanto ◽  
E. Y. Setyawan

Development in the current development sector has grown rapidly, in this development we can see a good potential to be developed, namely the development of bricks with good quality compared to using red bricks which production takes a long time. Batako is an alternative that can be used in the construction of a building, because currently the price of red brick is quite high because the production cost is quite expensive. Besides, the price of firewood used for cooking red brick is getting difficult. Meanwhile, the demand for brick gradually increased because brick was one of the main components in building construction. So it needs to be developed in making brick blocks because the time is relatively short in the drying process. Therefore the community service team made a brick making machine with a vibration system for compaction and a faster production process in brick making using a machine that has been made, so that it can increase partner income, who previously produced 120 pieces with a manual system using a machine that could produce 500 pieces of brick per day.


Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 711
Author(s):  
Zdzisław Kaliniewicz ◽  
Dariusz J. Choszcz

Viburnum is a genus of colorful and ornamental plants popular in landscape design on account of their high esthetic appeal. The physical properties of viburnum seeds have not been investigated in the literature to date. Therefore, the aim of this study was to characterize the seeds of selected Viburnum species and to search for potential relationships between their physical attributes for the needs of seed sorting operations. The basic physical parameters of the seeds of six Viburnum species were measured, and the relationships between these attributes were determined in correlation and regression analyses. The average values of the evaluated parameters were determined in the following range: terminal velocity—from 5.6 to 7.9 m s−1, thickness—from 1.39 to 1.87 mm, width—from 3.59 to 6.33 mm, length—from 5.58 to 7.44 mm, angle of external friction—from 36.7 to 43.8°, mass—from 16.7 to 35.0 mg. The seeds of V. dasyanthum, V. lentago and V. sargentii should be sorted in air separators, and the seeds of V. lantana and V. opulus should be processed with the use of mesh screens with round apertures to obtain uniform size fractions. The seeds of V. rhytodophyllum cannot be effectively sorted into batches with uniform seed mass, but they can be separated into groups with similar dimensions.


2005 ◽  
Vol 192 ◽  
pp. 275-280 ◽  
Author(s):  
L. Zampieri ◽  
M. Ramina ◽  
A. Pastorello

SummaryWe present the results of a systematic analysis of a group of Type II plateau supernovae that span a large range in luminosities, from faint objects like SN 1997D and 1999br to very luminous events like SN 1992am. The physical properties of the supernovae appear to be related to the plateau luminosity or the expansion velocity. The simultaneous analysis of the observed light curves, line velocities and continuum temperatures leads us to robust estimates of the physical parameters of the ejected envelope. We find strong correlations among several parameters. The implications of these results regarding the nature of the progenitor, the central remnant and the Ni yield are also addressed.


2017 ◽  
Vol 908 ◽  
pp. 118-122 ◽  
Author(s):  
Giedrius Balčiūnas ◽  
Viktor Kizinievič ◽  
Justinas Gargasas

Scientific literature mostly aims at investigation of composites with fibre hemp shives (FHS) aggregate and lime binder, although, such materials are characterised by pretty low mechanical properties. In order to obtain higher mechanical properties of a composite, it is appropriate to use cementitious binder. This work investigates physical properties of blocks from hemp shives aggregate and cementitious binder, manufactured in the expanded clay production line using vibro pressing technology. Following properties of the blocks are determined: freeze-thaw resistance, compressive strength, thermal conductivity and density. Thermal resistance according to EN ISO 6946 for the block with cavities is calculated as well. It is found that compressive strength of FHS-cement blocks may be up to 3.18 MPa when the density is of ~850 kg/m3 and thermal conductivity up to 0.135 W/(m∙K). It is found as well that the decrease of compressive strength is 8.7% after 25 freeze-thaw cycles.


2018 ◽  
Vol 33 ◽  
pp. 02075 ◽  
Author(s):  
Tatyana Matseevich

The theme of the research is important because it allows to use hybrid materials as finishing in the high-rise constructions. The aim of the study was the development of producing coloured hybrid materials based on liquid glass, a polyisocyanate, epoxy resin and 2.4-toluylenediisocyanate. The detailed study of the process of stress relaxation at different temperatures in the range of 20-100°C was provided. The study found that the obtained materials are subject to the simplified technology. The materials easy to turn different colors, and dyes (e.g. Sudan blue G) are the catalysts for the curing process of the polymeric precursors. The materials have improved mechanical relaxation properties, possess different color and presentable, can be easily combined with inorganic base (concrete, metal). The limit of compressive strength varies from 32 to 17.5 MPa at a temperature of 20 to 100°C. The values σ∞ are from 20.4 to 7.7 MPa within the temperature range from 20 to 100°C. The physical parameters of materials were evaluated basing on the data of stress relaxation: the initial stress σ0, which occurs at the end of the deformation to a predetermined value; quasi-equilibrium stress σ∞, which persists for a long time relaxation process. Obtained master curves provide prediction relaxation behavior for large durations of relaxation. The study obtained new results. So, the addition of epoxy resin in the composition of the precursor improves the properties of hybrid materials. By the method of IR spectroscopy identified chemical transformations in the course of obtaining the hybrid material. Evaluated mechanical performance of these materials is long-time. Applied modern physically-based memory functions, which perfectly describe the stress relaxation process.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2383
Author(s):  
Daniele Torsello ◽  
Mattia Bartoli ◽  
Mauro Giorcelli ◽  
Massimo Rovere ◽  
Rossella Arrigo ◽  
...  

We report on the microwave shielding efficiency of non-structural composites, where inclusions of biochar—a cost effective and eco-friendly material—are dispersed in matrices of interest for building construction. We directly measured the complex permittivity of raw materials and composites, in the frequency range 100 MHz–8 GHz. A proper permittivity mixing formula allows obtaining other combinations, to enlarge the case studies. From complex permittivity, finally, we calculated the shielding efficiency, showing that tailoring the content of biochar allows obtaining a desired value of electromagnetic shielding, potentially useful for different applications. This approach represents a quick preliminary evaluation tool to design composites with desired shielding properties starting from physical parameters.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Yong Zhang ◽  
Zhiguo Cao ◽  
Xiaomeng Shi

The cement-plaster bonded rock-like material is one of the most commonly used materials to simulate different rocks in physical model tests. However, the applicability of this material in solid-fluid coupling model tests is not clear because there are few research studies on the water-physical properties of this material and its similarity to the actual rock is uncertain. This paper presents a systemic experimental study on the water-physical properties of the cement-plaster bonded rock-like materials. The parameters of rock-like materials, including water absorption, softening coefficient, and permeability coefficient, were compared with those of actual rocks to analyse the applicability of such material. Then, the influence of proportion on the water-physical properties of this material was discussed. By multiple regression analysis of the test results, empirical equations between the water-physical parameters and proportions were proposed. The equations can be used to estimate the water-physical properties of cement-plaster bonded rock-like materials with specific proportion and thus to select suitable materials in the solid-fluid coupling physical model tests.


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