scholarly journals Measuring the Uniaxial Compressive Strength of Ice

1977 ◽  
Vol 19 (81) ◽  
pp. 213-223 ◽  
Author(s):  
F. D. Haynes ◽  
M. Mellor
Keyword(s):  
Compressive Strength ◽  
Accurate Method ◽  
Conventional Technique ◽  
Circular Cylinders ◽  
Specimen Preparation ◽  
Shear Stresses ◽  
Compression Tests ◽  
Strength Tests ◽  
Polycrystalline Ice ◽  
Measured Strength

AbstractAn attempt was made to develop a simple but accurate method for making compressive strength tests on right circular cylinders. Compliant loading platens were designed to apply uniform normal stress without introducing significant interface radial shear stresses. The compliant platens gave reproducible results that agree well with results obtained by a precise conventional technique. Accurate results were obtained with simple specimen preparation, and with short specimens where the length-to-diameter ratio was less than unity. Platens were made from a rubber-like urethane which was molded in aluminum cylinders to provide lateral restraint. Uniaxial compression tests on cylindrical polycrystalline ice specimens were made to determine the characteristics of the platens. For 21 specimens with ends prepared on a lapping plate to obtain a mirror finish, the measured strength showed a variation of only 13% for length-to-diameter ratios from 0.74 to 2.5, with no systematic trend. Another 21 specimens with length-to-diameter ratios of about 2.35 were tested with various platens and various methods of specimen end preparation. The strength for specimens with saw-cut ends and for those with ends lapped showed very little difference when tested with the rubber platens.

scholarly journals Measuring the Uniaxial Compressive Strength of Ice

1977 ◽  
Vol 19 (81) ◽  
pp. 213-223 ◽  
Author(s):  
F. D. Haynes ◽  
M. Mellor
Keyword(s):  
Compressive Strength ◽  
Accurate Method ◽  
Conventional Technique ◽  
Circular Cylinders ◽  
Specimen Preparation ◽  
Shear Stresses ◽  
Compression Tests ◽  
Strength Tests ◽  
Polycrystalline Ice ◽  
Measured Strength

AbstractAn attempt was made to develop a simple but accurate method for making compressive strength tests on right circular cylinders. Compliant loading platens were designed to apply uniform normal stress without introducing significant interface radial shear stresses. The compliant platens gave reproducible results that agree well with results obtained by a precise conventional technique. Accurate results were obtained with simple specimen preparation, and with short specimens where the length-to-diameter ratio was less than unity. Platens were made from a rubber-like urethane which was molded in aluminum cylinders to provide lateral restraint. Uniaxial compression tests on cylindrical polycrystalline ice specimens were made to determine the characteristics of the platens. For 21 specimens with ends prepared on a lapping plate to obtain a mirror finish, the measured strength showed a variation of only 13% for length-to-diameter ratios from 0.74 to 2.5, with no systematic trend. Another 21 specimens with length-to-diameter ratios of about 2.35 were tested with various platens and various methods of specimen end preparation. The strength for specimens with saw-cut ends and for those with ends lapped showed very little difference when tested with the rubber platens.

scholarly journals The Influence of Digestate on the Static Strength of Spring Rapeseeds (Brassica napus var. arvensis)

2019 ◽  
Vol 11 (7) ◽  
pp. 2133 ◽  
Author(s):  
Artur Przywara ◽  
Magdalena Kachel ◽  
Milan Koszel ◽  
Norbert Leszczyński ◽  
Artur Kraszkiewicz ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Biogas Production ◽  
Statistical Tests ◽  
Testing Machine ◽  
Mineral Fertilizers ◽  
Organic Substrates ◽  
Compression Tests ◽  
Strength Tests ◽  
Average Size ◽  
Comparable Mass

Biogas production occurs during methane fermentation from organic substrates and the mass remaining after fermentation, containing organic matter and valuable minerals having regard to plant nutrition, forms the digestate, which could be useful for fertilizing purposes and very beneficial in the case of the fertilization of rapeseeds. This paper focuses on the use of two forms of fertilization of rapeseeds—digestate and mineral fertilizers—in order to reduce the compressive strength of rapeseeds. The object presents results of compressive strength tests of three rape varieties (Bios, Feliks, Markus). The uniaxial compression tests between two parallel planes were made using a Zwick/Roell Z005 testing machine. Comparative analyses for the analyzed variables were carried out applying parametric and non-parametric statistical tests. On the basis of the conducted research, it was found that the distribution of the increase in the force crushing Bios and Feliks rapeseed varieties in both forms of cultivation was proportional to the increase in their mass. However, with a relatively comparable mass of Bios cv. seeds, in the case of the digestate use, a stronger correlation was found between the seed pressing force and its mass than for the multi-component fertilizer, understanding the need to apply more force to crush the seeds for this form of cultivation. In the conducted tests, the average size of rapeseed diameters of all varieties and forms of cultivation ranged from 1.81–1.95 mm, which indicates their good suitability for industrial purposes.

scholarly journals Humidity and specimen preparation procedure: influence on compressive strength of concrete blocks

2021 ◽  
Vol 14 (2) ◽  
Author(s):  
Guilherme Aris Parsekian ◽  
André Luis Christoforo ◽  
Amanda Duarte Escobal Mazzú ◽  
Gláucia Maria Dalfré
Keyword(s):  
Compressive Strength ◽  
Concrete Block ◽  
Block Type ◽  
Specimen Preparation ◽  
Standard Procedures ◽  
Strength Tests ◽  
Concrete Blocks ◽  
Compressive Strength Of Concrete ◽  
Average Block ◽  
Best Fit

abstract: It is extremely important that the quality control of the concrete block used in structural masonry is conducted based on standard procedures that allow reliable estimation of the properties of these components. This work aims to analyze and evaluate the influence of the concrete block moisture on the result of the compression test. Hollow concrete blocks were prepared and subsequently maintained in different environments for various periods of time and under different conditions of temperature and humidity to determine the influence of the type of drying on the relative humidity of the block at the time of testing and consequently on its compressive strength. As a conclusion, it can be stated that, because it is necessary to use water in the process, the grinding rectification of the faces of the blocks led them to have high humidity, above 70%. If tested in this condition, the results of the compressive strength tests will be lower than that of blocks under usual environmental conditions. No differences were found in the average block strength when they were kept dry in the controlled environment of the laboratory during periods of 24 or 48 h. After grinding, it is not necessary to dry the blocks inside an oven at 40ºC before the tests; simply leaving them at a usual room temperature of 23ºC and humidity of 40 ± 5% for 24h is sufficient. The attempt to accelerate drying in an oven at 100ºC is not adequate because this leads to an increase in the compressive strength. From the results, it was possible to determine expressions to correlate the compressive strength as a function of the moisture of the block at the time of the test. The best-fit expressions are distinct for each block type, but the formulations are consistent in indicating a considerable difference in resistance as a function of moisture.

Failure conditions of solid wood on off-axis compression testing

Holzforschung ◽  
2019 ◽  
Vol 73 (3) ◽  
pp. 251-258
Author(s):  
Hiroshi Yoshihara
Keyword(s):  
Compressive Strength ◽  
Physical Meaning ◽  
Solid Wood ◽  
Shear Stresses ◽  
Compression Tests ◽  
Interaction Terms ◽  
Axis Compression ◽  
Failure Conditions ◽  
The Relationship ◽  
Normal And Shear Stresses

Abstract Off-axis compression tests (OACT) were conducted on solid wood from six tree species, and the relationship between the off-axis compressive strength (OACStr) and the off-axis angle was predicted under the conventional Hill-type quadratic failure conditions, off-axis special failure conditions, and under a condition proposed in this study, which contains terms of interaction between the normal and shear stresses. The latter was an effective approach for accurately predicting the OACStr, although the physical meaning of the interaction terms is not yet clear. Under the off-axis specialized conditions, the approach was simple and accurate for predicting the OACStr, which includes the 45° off-axis angle.

scholarly journals Analysis of the Influencing Factors of FDM-Supported Positions for the Compressive Strength of Printing Components

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4008
Author(s):  
Zhengkai Feng ◽  
Heng Wang ◽  
Chuanjiang Wang ◽  
Xiujuan Sun ◽  
Shuai Zhang
Keyword(s):  
Compressive Strength ◽  
Stress Intensity ◽  
Influencing Factors ◽  
Fused Deposition Modeling ◽  
Experimental Results ◽  
Compression Tests ◽  
Suspended State ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
Reference Experiment

Fused deposition modeling (FDM) has the advantage of being able to process complex workpieces with relatively simple operations. However, when processing complex components in a suspended state, it is necessary to add support parts to be processed and formed, which indicates an excessive dependence on support. The stress intensity of the supported positions of the printing components can be modified by changing the supporting model of the parts, their density, and their distance in relation to the Z direction in the FDM printing settings. The focus of the present work was to study the influences of these three modified factors on the stress intensity of the supporting position of the printing components. In this study, 99 sets of compression tests were carried out using a position of an FDM-supported part, and the experimental results were observed and analyzed with a 3D topographic imager. A reference experiment on the anti-pressure abilities of the printing components without support was also conducted. The experimental results clarify how the above factors can affect the anti-pressure abilities of the supporting positions of the printing components. According to the results, when the supporting density is 30% and the supporting distance in the Z direction is Z = 0.14, the compressive strength of the printing component is lowest. When the supporting density of the printing component is ≤30% and the supporting distance in the Z direction is Z ≥ 0.10, the compressive strength of printing without support is greater than that of the linear support model. Under the same conditions, the grid-support method offers the highest compressive strength.

scholarly journals Behavior of Offshore Pile in Calcareous Sand—Case Study

2021 ◽  
Vol 9 (8) ◽  
pp. 839
Author(s):  
Tarek N. Salem ◽  
Nadia M. Elkhawas ◽  
Ahmed M. Elnady
Keyword(s):  
Load Capacity ◽  
High Stress ◽  
Embedment Depth ◽  
Shear Stresses ◽  
Northern Coast ◽  
Compression Tests ◽  
Calcareous Sand ◽  
Element Analysis ◽  
Mixing Ratios

The erosion of limestone and calcarenite ridges that existed parallel to the Mediterranean shoreline forms the calcareous sand (CS) formation at the surface layer of Egypt's northern coast. The CS is often combined with broken shells which are considered geotechnically problematic due to their possible crushability and relatively high compressibility. In this research, CS samples collected from a site along the northern coast of Egypt are studied to better understand its behavior under normal and shear stresses. Reconstituted CS specimens with different ratios of broken shells (BS) are also investigated to study the effect of BS ratios on the soil mixture strength behavior. The strength is evaluated using laboratory direct-shear and one-dimensional compression tests (oedometer test). The CS specimens are not exposed to significant crushability even under relatively high-stress levels. In addition, a 3D finite element analysis (FEA) is presented in this paper to study the degradation offshore pile capacity in CS having different percentages of BS. The stress–strain results using oedometer tests are compared with a numerical model, and it gave identical matching for most cases. The effects of pile diameter and embedment depth parameters are then studied for the case study on the northern coast. Three different mixing ratios of CS and BS have been used, CS + 10% BS, CS + 30% BS, and CS + 50% BS, which resulted in a decrease of the ultimate vertical compression pile load capacity by 8.8%, 15%, and 16%, respectively.

scholarly journals Compression and Strain Predictive Models in Non-Structural Recycled Concretes Made from Construction and Demolition Wastes

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3177
Author(s):  
Evelio Teijón-López-Zuazo ◽  
Jorge López-Rebollo ◽  
Luis Javier Sánchez-Aparicio ◽  
Roberto Garcia-Martín ◽  
Diego Gonzalez-Aguilera
Keyword(s):  
Compressive Strength ◽  
Predictive Models ◽  
Unconfined Compressive Strength ◽  
Image Correlation ◽  
Peak Strain ◽  
Compression Tests ◽  
Maximum Peak ◽  
3D Digital Image Correlation ◽  
Granulometric Analysis ◽  
Physical And Chemical

This work aims to investigate different predictive models for estimating the unconfined compressive strength and the maximum peak strain of non-structural recycled concretes made up by ceramic and concrete wastes. The extensive experimental campaign carried out during this research includes granulometric analysis, physical and chemical analysis, and compression tests along with the use of the 3D digital image correlation as a method to estimate the maximum peak strain. The results obtained show that it is possible to accurately estimate the unconfined compressive strength for both types of concretes, as well as the maximum peak strain of concretes made up by ceramic waste. The peak strain for mixtures with concrete waste shows lower correlation values.

Preparation and Mechanical Properties of Polyethylene-Portland Cement Composites

2009 ◽  
Vol 1242 ◽  
Author(s):  
Rivas-Vázquez L.P. ◽  
Suárez-Orduña R. ◽  
Valera-Zaragoza M. ◽  
Máas-Díaz A. De la L. ◽  
Ramírez-Vargas E.
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Portland Cement ◽  
Plastic Waste ◽  
Cement Composites ◽  
Compression Tests ◽  
Standard Samples ◽  
Cement Ratio ◽  
Reinforcing Fibers ◽  
Waste Polyethylene

ABSTRACTThe effects of waste polyethylene aggregate as admixture agent in Portland cement at different addition polyethylene/cement ratios from 0.0156 to 0.3903 were investigated. The reinforced samples were prepared according the ASTM C 150 Standard (samples of 5 × 5 × 5 cm). The reinforcing fibers were milling at a size of 1/25 in diameter, form waste and used them to evaluate the effects in mechanical properties in cement-based composites. The evaluation of polyethylene as additive was based on results of density and compression tests. The 28-day compressive strength of cement reforced with plastic waste at a replacement polyethylene/cement ratio of 0.0468 was 23.5 MPa compared to the control concrete (7.5 MPa). The density of cement replaced with polyethylene varies from 2.114 (0% polyethylene) to 1.83 g/cm3 by the influence of polyethylene.

Dynamic and Quasi-Static Compressive Deformation Behaviour of Polyimide Foam at Various Elevated Temperature

2014 ◽  
Vol 566 ◽  
pp. 158-163 ◽  
Author(s):  
A. Yosimoto ◽  
Hidetoshi Kobayashi ◽  
Keitaro Horikawa ◽  
Keiko Watanabe ◽  
Kinya Ogawa
Keyword(s):  
Compressive Strength ◽  
Room Temperature ◽  
Deformation Behaviour ◽  
Testing Machine ◽  
Negative Temperature ◽  
Strain Rates ◽  
Compression Tests ◽  
Hopkinson Pressure Bar ◽  
Universal Testing ◽  
Pressure Bar

In order to clarify the effect of strain rate and test temperature on the compressive strength and energy absorption of polyimide foam, a series of compression tests for the polyimide foam with two different densities were carried out. By using three testing devices, i.e. universal testing machine, dropping weight machine and sprit Hopkinson pressure bar apparatus, we performed a series of compression tests at various strain rates (10-3~103s-1) and at several test temperatures in the range of room temperature to 280 ̊C. At over 100 s-1, the remarkable increase of flow stress was observed. The negative temperature dependence of strength was also observed.

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