Mechanical characterisation of hydrogels using Brillouin microscopy, ultrasound and unconfined compression tests (Conference Presentation)

2017 ◽  
Author(s):  
Pei-Jung Wu ◽  
Irina V. Kabakova ◽  
ChengZe Song ◽  
Carl Paterson ◽  
Darryl R. Overby ◽  
...  
Keyword(s):  
Compression Tests ◽  
Unconfined Compression ◽  
Mechanical Characterisation

Microstructural changes in soft quick clay at failure

1970 ◽  
Vol 7 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Roland Pusch
Keyword(s):  
Shear Deformation ◽  
Shear Zone ◽  
Residual Strength ◽  
Rigid Bodies ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Shear Forces ◽  
Microstructural Investigation ◽  
Shear Process ◽  
Quick Clay

A series of unconfined compression tests has been made on a marine, quick clay and small specimens were extracted for microstructural investigation. The natural microstructural pattern was characterized by a network of small aggregates connected by links of particles. The links broke down successively at increasing shear deformation and formed domain-like groups of particles. In the macroscopic shear zone the shear forces tended to orient and deform the aggregates.The aggregates behaved as rigid bodies to a certain stress level during the shear process. The concept of residual strength may correspond to the state where the majority of the links have been broken while the aggregates are still intact.

Stabilization of clayey subgrade with waste pumice for road infrastructure

2015 ◽  
Vol 22 (5) ◽  
Author(s):  
Ömür Çimen ◽  
Mehmet Saltan ◽  
S. Nilay Keskin
Keyword(s):  
Mechanical Properties ◽  
Road Construction ◽  
High Plasticity ◽  
Test Results ◽  
Index Properties ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Swelling Potential ◽  
Project Costs ◽  
High Plasticity Clay

AbstractHigh-plasticity clayey subgrade, which is unsuitable for road construction, may sometimes occur along highway routes. In such cases, engineers need to change the route of a highway project, resulting in an increase in road length and project costs. In this study, waste pumice was examined for stabilization of high-plasticity clayey subgrade, which is inappropriate for road construction. For this purpose, the physical and index properties of clay and pumice were determined. Then, the pumice was mixed with high plasticity clay at different ratios by weight. By performing standard Proctor compaction tests on the mixtures, the effects of adding pumice on compaction were also studied. Unconfined compression tests and California bearing ratio (CBR) tests were performed on all pumice-clay mixtures, and the test results and the CBR ratios were compared for each sample, respectively. The results showed that pumice stabilization improved the mechanical properties and reduced the swelling potential of high plasticity clayey subgrade.

scholarly journals The Effect of Polymer-Cement Stabilization on the Unconfined Compressive Strength of Liquefiable Soils

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Ateş
Keyword(s):  
Compressive Strength ◽  
Compression Strength ◽  
Unconfined Compressive Strength ◽  
Soil Stabilization ◽  
Sandy Soils ◽  
Pulse Velocity ◽  
Unit Weight ◽  
Unconfined Compression Strength ◽  
Compression Tests ◽  
Unconfined Compression

Soil stabilization has been widely used as an alternative to substitute the lack of suitable material on site. The use of nontraditional chemical stabilizers in soil improvement is growing daily. In this study a laboratory experiment was conducted to evaluate the effects of waterborne polymer on unconfined compression strength and to study the effect of cement grout on pre-venting of liquefiable sandy soils. The laboratory tests were performed including grain size of sandy soil, unit weight, ultrasonic pulse velocity, and unconfined compressive strength test. The sand and various amounts of polymer (1%, 2%, 3%, and 4%) and cement (10%, 20%, 30%, and 40%) were mixed with all of them into dough using mechanical kneader in laboratory conditions. Grouting experiment is performed with a cylindrical mould of  mm. The samples were subjected to unconfined compression tests to determine their strength after 7 and 14 days of curing. The results of the tests indicated that the waterborne polymer significantly improved the unconfined compression strength of sandy soils which have susceptibility of liquefaction.

Influence of Curing Pressure on Unconfined Compressive Strength of Cemented Clay

2018 ◽  
Vol 928 ◽  
pp. 263-268 ◽  
Author(s):  
Anuchit Uchaipichat
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Cement Content ◽  
Soft Clay ◽  
Peak Stress ◽  
Confining Pressure ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Soil Cement ◽  
Curing Pressure

The soil-cement columns are generally installed and cured in the soft clay layers under confining pressure. The strength of the soil-cement columns may be influenced by confining pressure during curing period. In this study, the main objective was to study the influence of curing pressure on unconfined compressive strength of cemented clay. A series of unconfined compression tests was performed on a cement admixed clay sample cured under pressure values of 0 kPa (atmospheric pressure), 25kPa, 50kPa and 100 kPa using a typical unconfined compression equipment. The test samples with values of cement content of 0.5, 1.0 and 2.0 percent were cured for 28 days.The stress-strain curves obtained from all tests show a peak value of stress. The unconfined compressive strength or peak stress obviously increased with increasing cement content for all curing pressure conditions. It can be observed that the strength of samples gradually increased with curing pressure for cement content of 0.5 percent. For cement contents of 1.0 and 2.0 percent, the strengths of samples cured under pressures of 25 kPa dramatically increased from the strength of samples cured without pressure (0 kPa), however, the strengths of samples for curing pressures of 25, 50 and 100 kPa were not clearly different.

Photogrammetry-Based Method to Determine the Absolute Volume of Soil Specimen during Triaxial Testing

2020 ◽  
Vol 2674 (8) ◽  
pp. 206-218
Author(s):  
Sara Fayek ◽  
Xiaolong Xia ◽  
Lin Li ◽  
Xiong Zhang
Keyword(s):  
Unsaturated Soils ◽  
Optimization Techniques ◽  
Triaxial Tests ◽  
Triaxial Testing ◽  
Soil Specimen ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Absolute Volume ◽  
Triaxial Cell ◽  
The Absolute

Triaxial tests are used extensively to evaluate stress-strain behavior for both saturated and unsaturated soils. A literature review indicates that all conventional triaxial test methods measure the relative volume of soil; however, between the initial measurements and the start of the triaxial tests, there are unavoidably disturbances during installation that cause deviation of soil volume from that at the initial condition. Recently image-based methods have been developed to measure the absolute volume of soil specimens. However, these methods still have a major limitation in their inability to determine top and bottom boundaries between the soil specimen, and the top and bottom caps. This paper proposes a photogrammetry-based method to overcome this limitation by developing a mathematically rigorous technique to determine the upper and lower boundaries of soil specimens during triaxial testing. The photogrammetry technique was used to determine the orientations of the camera, and the shape and location of the acrylic cell. Multiple ray-tracings and least-square optimization techniques were also applied to obtain the coordinates of any point inside the triaxial cell, and thus back-calculate the upper and lower boundaries. With these boundaries and the side surface, a triangular surface mesh was constructed and the specimen volume was then calculated in both unconfined compression tests and triaxial tests. The calculation procedures are presented in detail with validation tests performed on a cylindrical specimen to evaluate the accuracy of the method. Results indicate that the accuracy of the proposed method is up to 0.023% in unconfined compression tests and 0.061% in triaxial tests.

scholarly journals Unified Strength Model of Asphalt Mixture under Various Loading Modes

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 889 ◽  
Author(s):  
Chengdong Xia ◽  
Songtao Lv ◽  
Lingyun You ◽  
Dong Chen ◽  
Yipeng Li ◽  
...  
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Structure Design ◽  
Strength Model ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Direct Tension ◽  
Indirect Tension ◽  
Pavement Structure ◽  
Loading Modes

Although the rutting resistance, fatigue cracking, and the resistance to water and frost are important for the asphalt pavement, the strength of asphalt mixture is also an important factor for the asphalt mixture design. The strength of asphalt mixture is directly associated with the overall performance of asphalt mixture. As a top layer material of asphalt pavement, the strength of asphalt mixture plays an indispensable role in the top structural bearing layer. In the present design system, the strength of asphalt pavement is usually achieved via the laboratory tests. The stress states are usually different for the different laboratory approaches. Even at the same stress level, the laboratory strengths of asphalt mixture obtained are significantly different, which leads to misunderstanding of the asphalt mixtures used in asphalt pavement structure design. The arbitrariness of strength determinations affects the effectiveness of the asphalt pavement structure design in civil engineering. Therefore, in order to overcome the design deviation caused by the randomness of the laboratory strength of asphalt mixtures, in this study, the direct tension, indirect tension, and unconfined compression tests were implemented on the specimens under different loading rates. The strength model of asphalt mixture under different loading modes was established. The relationship between the strength ratio and loading rate of direct tension, indirect tension, and unconfined compression tests was adopted separately. Then, one unified strength model of asphalt mixture with different loading modes was established. The preliminary results show that the proposed unified strength model could be applied to improve the accurate degree of laboratory strength. The effectiveness of laboratory-based asphalt pavement structure design can therefore be promoted.

scholarly journals Deformation behaviour and strength of frozen sand

1980 ◽  
Vol 17 (1) ◽  
pp. 74-88 ◽  
Author(s):  
V. R. Parameswaran
Keyword(s):  
Compressive Strength ◽  
Strain Rate ◽  
Deformation Behaviour ◽  
Unfrozen Water ◽  
Strain Rates ◽  
Linear Extrapolation ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Ottawa Sand ◽  
Frozen Sand

Uniaxial unconfined compression tests were carried out on frozen saturated Ottawa sand containing about 20% by weight of water, at temperatures between −2 and − 15°C, and at strain rates varying between 10−7 and 10−2 s−1. The compressive strength and the initial tangent modulus increased with increasing strain rate and with decreasing temperature. At −2°C, values of strength and modulus were considerably lower than those predicted by linear extrapolation of the values observed at lower temperatures, on a log–log scale. This could be due to the presence of unfrozen water in the samples at −2°C.

Modulus of Elasticity of Reinforced Clay

2011 ◽  
Vol 261-263 ◽  
pp. 969-973 ◽  
Author(s):  
Amin Chegenizadeh ◽  
Hamid Nikraz
Keyword(s):  
Aspect Ratio ◽  
Modulus Of Elasticity ◽  
Fibre Length ◽  
Reinforced Soil ◽  
Fibre Content ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Pavement Engineering ◽  
Grade Material ◽  
Reinforced Clay

Reinforced soil has been among the most effective soil modification materials. Its use has been expanded rapidly into civil engineering, geotechnical engineering and pavement engineering. Reinforcing subgarde in pavement systems has always been an issue. This study focuses on effect of fibre inclusion on the modulus of elasticity of subgrade material. Plastic fibre was used for this investigation. Fibre contents and aspect ratio have been changed during these tests. The fibre percentage varied from 0 % (for unreinforced samples) to 3%. Clay was used as sub grade material. Unconfined compression tests were carried out to investigate behaviour of the composite under different condition. The fibre length and fibre content found to play important rule on the modulus of elasticity of fibre. Furthermore it was observed that ductility of sample increased by fibre inclusion.

Unconfined Compression Strength of Tianluoshan Relic Soils Solidified by Silicone

2012 ◽  
Vol 610-613 ◽  
pp. 2908-2911 ◽  
Author(s):  
Xin Jun Chai ◽  
Chun Feng He ◽  
Yan Sheng Gao
Keyword(s):  
Compressive Strength ◽  
Compression Strength ◽  
Potential Application ◽  
Influence Factors ◽  
Curing Time ◽  
Unconfined Compression Strength ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Moisture Condition ◽  
Curing Condition

Tianluoshan relic sites is a typical earthen sites located at moisture circumstances. The potential application of silicone for strengthening Tianluoshan relic soils were evaluated by a series of unconfined compression tests. The main considered influence factors includue: curing condition, curing time, and variation of water content. The results show that the compressive strength of Tianluoshan relic soils solidified by silicon increase with curing time, and silicon can effectively improve the strength of Tianluoshan relic soils under constant temperature & moisture condition.

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