scholarly journals Field Test 1 of Compressive Strength of First-Year Sea Ice

1983 ◽  
Vol 4 ◽  
pp. 253-259 ◽  
Author(s):  
N. K. Sinha
Keyword(s):  
Compressive Strength ◽  
Sea Ice ◽  
Failure Time ◽  
Rate Sensitivity ◽  
Test System ◽  
First Year ◽  
Test Machine ◽  
Baffin Island ◽  
Test Results ◽  
Average Strain Rate

A test program undertaken in April 1981 on the uniaxial compressive strength of freshly recovered first-year columnar-grained sea ice at a portable field laboratory floating on top of the ice cover in Eclipse Sound, Baffin Island, Canadian Arctic, is reported. Using a small battery-operated test machine, both vertical and horizontal samples were tested so that the load could be applied either parallel or perpendicular to the axis of the columns. Rate sensitivity of the observed strength is discussed in terms of measured average strain-rate and average stress-rate to upper yield or failure. Strain and time aspects of the test results are considered as well. Although vertical samples showed considerably greater strength than horizontal samples, no significant differences were detected in the failure strains. Examination of the interdependence of failure stress and failure time revealed certain anomalies in the results for vertical samples that could be linked to the performance characteristics of the test machine. As such problems could be common to any test system, methods of analysis are proposed for rational examination of the results.

scholarly journals Field Test 1 of Compressive Strength of First-Year Sea Ice

1983 ◽  
Vol 4 ◽  
pp. 253-259 ◽  
Author(s):  
N. K. Sinha
Keyword(s):  
Compressive Strength ◽  
Sea Ice ◽  
Failure Time ◽  
Rate Sensitivity ◽  
Test System ◽  
First Year ◽  
Test Machine ◽  
Baffin Island ◽  
Test Results ◽  
Average Strain Rate

A test program undertaken in April 1981 on the uniaxial compressive strength of freshly recovered first-year columnar-grained sea ice at a portable field laboratory floating on top of the ice cover in Eclipse Sound, Baffin Island, Canadian Arctic, is reported. Using a small battery-operated test machine, both vertical and horizontal samples were tested so that the load could be applied either parallel or perpendicular to the axis of the columns. Rate sensitivity of the observed strength is discussed in terms of measured average strain-rate and average stress-rate to upper yield or failure. Strain and time aspects of the test results are considered as well. Although vertical samples showed considerably greater strength than horizontal samples, no significant differences were detected in the failure strains. Examination of the interdependence of failure stress and failure time revealed certain anomalies in the results for vertical samples that could be linked to the performance characteristics of the test machine. As such problems could be common to any test system, methods of analysis are proposed for rational examination of the results.

scholarly journals Uniaxial compressive strength of first-year and multi-year sea ice

1984 ◽  
Vol 11 (1) ◽  
pp. 82-91 ◽  
Author(s):  
N. K. Sinha
Keyword(s):  
Compressive Strength ◽  
Sea Ice ◽  
Strain Rate ◽  
Fresh Water ◽  
Horizontal Plane ◽  
Rate Sensitivity ◽  
Ductile Material ◽  
First Year ◽  
Water Ice ◽  
Frazil Ice

Strain-rate and stress-rate sensitivity of the compressive strength of first-year columnar-grained ice, first-year congealed frazil ice, and columnar-grained ice from an old floe have been investigated with load applied in the horizontal plane. In spite of similar salinity and density, the frazil ice proved to be considerably stronger than the columnar-grained ice. The strength of porous old floe ice with columnar-grained structure was very much the same as that of first-year ice of similar structure, but the clear bulk ice of the old floe was strongest. Rate sensitivity of strength for the three types of saline ice was similar to that of fresh-water ice. Ductility of the old clear ice (as measured by the strain at upper yield) was the same as that of fresh-water ice; ductility of porous old ice was comparable to that of new frazil ice. New columnar-grained ice proved to be the most ductile material. Key words: columnar-grained, compressive strength, ductility, first-year, frazil, multi-year, rate sensitivity, sea ice.

Effect of Emulsified Asphalt Content on Mechanical Property of Cement and Emulsified Asphalt Mortar

2014 ◽  
Vol 587-589 ◽  
pp. 1132-1136
Author(s):  
Yue Li ◽  
Ping Wang
Keyword(s):  
Compressive Strength ◽  
Bending Strength ◽  
Bending Test ◽  
Test Machine ◽  
Peak Strain ◽  
Test Results ◽  
Slurry System ◽  
Similar Appearance ◽  
Emulsified Asphalt ◽  
Ca Mortar

Uniaxial compression and bending test of CA mortar, which have six different dosage of emulsified asphalt and the same dry material, is carried out with a electronic universal test machine. It turns out that: when the dosage of emulsified asphalt is lacked, the CA mortar cannot be uniform and stable slurry system; within the range of 300~680 mL emulsified asphalt, slurry state of mortar is good, no separation, and have good liquidity, in this range, with the increasing dosage of emulsified asphalt, compressive strength, elastic modulus and peak strain are gradually reduced, while ratio of bending strength to compressive strength rise at the beginning, then decline within a narrow range; The 1st and 2nd slurry is not stable, they appear separation and the surfaced asphalt, which have similar appearance and mechanical properties to cement mortar, and the last four groups of test results have great difference from the former two groups.

scholarly journals Mechanical Properties of First Year Sea Ice in Saroma Lagoon

1985 ◽  
Vol 6 ◽  
pp. 278-280
Author(s):  
Hisao Matsushita ◽  
Nobuyoshi Yashima
Keyword(s):  
Compressive Strength ◽  
Sea Ice ◽  
Test Specimen ◽  
Bending Strength ◽  
Growth Direction ◽  
Cross Sectional Area ◽  
First Year ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Cross

This paper deals with compressive strength vs temperature characteristics (-40 ºC to -2ºC), size effect (cross-sectional area of test specimen) and probability distribution of compressive strength and fracture toughness KIC (corresponding to notch effect in bending strength), of first year sea ice sampled from Saroma Lagoon. The main experimental results are as follows. (1) Temperature dependent compressive fracture modes: at temperatures of -20 ºC to 0ºC, crush fracture is dominant, and at temperatures of -40 ºC to -20 C, brittle fracture is dominant. (2) The larger the cross-sectional area of a test specimen, the lower the compressive strength becomes. It is inferred that the number of weak spots increases with increase in the cross-sectional area of the test piece, which thus becomes more susceptible to fracture. (3) The scatter of compressive strength can be approximated by a normal distribution curve. (4) The KIC values of sea ice are below 10 kg/cm2cm, though they change slightly depending on the dimensions of test pieces, the relative angle between crystal growth direction and load direction, environmental condition (air or water), and testing method.

Influence of Aggregates on Cracking Sensitivity of Concrete

2012 ◽  
Vol 204-208 ◽  
pp. 3299-3302 ◽  
Author(s):  
Xia Chen ◽  
Jian Jun Yan ◽  
Hua Quan Yang
Keyword(s):  
Compressive Strength ◽  
Stress Test ◽  
Interfacial Transition Zone ◽  
Cement Matrix ◽  
Test Machine ◽  
Test Results ◽  
Concrete Cracking ◽  
Natural Aggregate ◽  
Compressive Strength Of Concrete ◽  
Cracking Sensitivity

Concrete cracking sensitivity made from different aggregates was compared with employment of advanced temperature and stress test machine by tracking thermal and stress development of concrete with age and elements distribution in interfacial transition zone of each concrete was explored by SEM and EDS. Test results indicated that compressive strength of concrete made from basalt and limestone was greater than diorite and natural aggregate and crack resistance of concrete based on cracking sensitivity comparison in terms of cracking temperature varying from minus 0.3°C to minus 2.5°C as diorite, basalt, limestone and natural aggregate. Elements Ca and Mg were apparently accumulated in vicinity of ITZ and some reaction between limestone and cement matrix might have taken place which blurred the boundary between aggregates and cement matrix.

scholarly journals Growth Rate and Salinity Profile of First-Year Sea Ice in the High Arctic

1981 ◽  
Vol 27 (96) ◽  
pp. 315-330 ◽  
Author(s):  
M. Nakawo ◽  
N. K Sinha
Keyword(s):  
Growth Rate ◽  
Sea Ice ◽  
Physical Properties ◽  
High Arctic ◽  
First Year ◽  
Baffin Island ◽  
Growth Season ◽  
Method Of Calculation ◽  
Salinity Profile ◽  
Snow Conditions

AbstractThis paper describes the growth of sea ice and the salinity profiles observed in Eclipse Sound near Pond Inlet, Baffin Island, Canada, during the winter of 1977–78. A numerical method of calculation has been developed to incorporate the variations in snow conditions and physical properties of ice and snow during the growth season. It is shown that the growth rate can be predicted reasonably well. It is also shown that the vertical salinity profile in the ice towards the end of the season, provides a record of previous climatological conditions. A dependence has been shown between the predicted growth rate and the measured salinity.

Uniaxial Constant Compressive Stress Creep Tests on Sea Ice

1995 ◽  
Vol 117 (4) ◽  
pp. 283-289 ◽  
Author(s):  
N. K. Sinha ◽  
C. Zhan ◽  
E. Evgin
Keyword(s):  
Compressive Strength ◽  
Sea Ice ◽  
Strain Rate ◽  
Compressive Stress ◽  
Axial Strain ◽  
Acoustic Emissions ◽  
Constant Strain Rate ◽  
Rate Sensitivity ◽  
Load Test ◽  
Creep Tests

First-year columnar-grained sea ice from Resolute Passage (74° 42′ N, 94° 50′ W), off Barrow Strait in the Canadian High Arctic, was tested under constant uniaxial compressive stress applied normal to the length of the columns. Creep tests were performed at 263 K, 253 K, and 243 K in the stress range of 0.7 to 2.5 MPa, using prismatic samples with dimensions of 50 mm × 100 mm × 250 mm. Because three-dimensional creep data are extremely useful for developing constitutive equations, axial strain was measured in conjunction with the measurements of two lateral strains and acoustic emissions. The deformations were measured using displacement gages mounted on the samples. A description of the experimental procedures and the observations are presented here. One-to-one correspondence has been obtained between the present results on the dependence of minimum creep rate on stress and previous data on the dependence of uniaxial compressive strength on strain rate under constant strain rate. The strain-rate sensitivity of compressive strength can, therefore, be obtained from creep tests which can be performed by using simple dead-load test systems.

scholarly journals Mechanical Properties of First Year Sea Ice in Saroma Lagoon

1985 ◽  
Vol 6 ◽  
pp. 278-280
Author(s):  
Hisao Matsushita ◽  
Nobuyoshi Yashima
Keyword(s):  
Compressive Strength ◽  
Sea Ice ◽  
Test Specimen ◽  
Bending Strength ◽  
Growth Direction ◽  
Cross Sectional Area ◽  
First Year ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Cross

This paper deals with compressive strength vs temperature characteristics (-40 ºC to -2ºC), size effect (cross-sectional area of test specimen) and probability distribution of compressive strength and fracture toughness KIC (corresponding to notch effect in bending strength), of first year sea ice sampled from Saroma Lagoon. The main experimental results are as follows. (1) Temperature dependent compressive fracture modes: at temperatures of -20 ºC to 0ºC, crush fracture is dominant, and at temperatures of -40 ºC to -20 C, brittle fracture is dominant. (2) The larger the cross-sectional area of a test specimen, the lower the compressive strength becomes. It is inferred that the number of weak spots increases with increase in the cross-sectional area of the test piece, which thus becomes more susceptible to fracture. (3) The scatter of compressive strength can be approximated by a normal distribution curve. (4) The KIC values of sea ice are below 10 kg/cm2 cm, though they change slightly depending on the dimensions of test pieces, the relative angle between crystal growth direction and load direction, environmental condition (air or water), and testing method.

scholarly journals The Borehole Jack—Is It a Useful Arctic Tool?

1987 ◽  
Vol 109 (4) ◽  
pp. 391-397 ◽  
Author(s):  
Nirmal K. Sinha
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Melting Point ◽  
Sea Ice ◽  
High Arctic ◽  
Test System ◽  
Simultaneous Recording ◽  
First Year ◽  
Test Procedures ◽  
Operational Conditions

As the working temperatures in ice are very close to its melting point, it behaves viscoelastically and experiences what is commonly known as high temperature embrittlement. Its mechanical properties are rate sensitive and analysis must include load and displacement history. Borehole jack tests can be improved by the use of an electrohydraulic pump in conjunction with simultaneous recording of pressure and diametral displacement as a function of time. These small but significant modifications in the test procedures permit analysis of the response of a borehole jack test system under operational conditions in the High Arctic in first-year and multi-year sea ice.

Confined Compressive Strength of Horizontal First-Year Sea Ice Samples

1991 ◽  
Vol 113 (4) ◽  
pp. 344-351 ◽  
Author(s):  
J. A. Richter-Menge
Keyword(s):  
Compressive Strength ◽  
Sea Ice ◽  
Axial Stress ◽  
Testing Machine ◽  
Constant Strain Rate ◽  
First Year ◽  
Strain Rates ◽  
Triaxial Cell ◽  
Testing Techniques ◽  
Prudhoe Bay

A total of 110 first-year sea ice samples from Prudhoe Bay, Alaska, were tested in unconfined and confined constant strain rate compression. All of the tests were performed in the laboratory on a closed-loop electrohydraulic testing machine at −10°C. The confined tests were performed in a conventional triaxial cell (σ1>σ2=σ3) that maintained a constant ratio between the radial and axial stress (σ2/(σ1)=constant) to simulate true loading conditions. Three strain rates (10−2, 10−3, and 10−5/s) and three σ2/σ1 ratios (0.25, 0.50, and 0.75) were investigated. This paper summarizes the field sampling and testing techniques and presents data on the effect of confinement on the compressive strength, initial tangent modulus, and failure strain of the ice.

Sign in / Sign up

Export Citation Format

Share Document