Wetting-induced volume changes in compacted silty clays and high-plasticity clays

Wetting-induced deformations of compacted fine-grained soils are of particular interest in earthworks engineering, where embankment design needs to take into account potential future water-content variations. The influence of compaction rate on swelling potential and, more generally, wetting-induced deformations are analyzed in this paper on the basis of an original physical microstructural model. The interpretation of macroscopic experimental results obtained on a high-plasticity clay and a silty clay shows that the model enables quantitative description of intra- and inter-aggregate pore volume changes due to wetting. Using this approach, a fundamental difference was observed between the high-plasticity clay and the silty clay in wetting tests under vertical stress: tests performed on the high-plasticity clay can be analyzed using a microstructural model, whereas this model is not relevant for the analysis of silty clay behaviour, which is better interpreted in the framework of a conventional elastoplastic model. The interpretations were compared to microstructure observations, which support the main tendencies deduced from the model.

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Stabilization of clayey subgrade with waste pumice for road infrastructure

Science and Engineering of Composite Materials ◽

10.1515/secm-2013-0315 ◽

2015 ◽

Vol 22 (5) ◽

Cited By ~ 2

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.

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The effect of egg shell powder on the compression strength of fine-grained soil

MATEC Web of Conferences ◽

10.1051/matecconf/201819503011 ◽

2018 ◽

Vol 195 ◽

pp. 03011

Author(s):

Niken Silmi Surjandari ◽

Raden Harya Dananjaya ◽

Ely Jauharotus S

Keyword(s):

Low Cost ◽

High Plasticity ◽

Test Results ◽

Fine Grained ◽

Structure Changes ◽

Liquidity Index ◽

Fine Grained Soil ◽

Problematic Soils ◽

High Plasticity Clay ◽

Egg Shell

High plasticity clay has several problems including a high plasticity index and low bearing capacity. Stabilization of high plasticity clay is still extensively explored, especially for a low-cost and easily obtainable material. The purpose of this research is to study the effect of eggshell powder (ESP) on high plasticity clay. This research uses a soil sample obtained from Jenggrik Village, Ngawi Regency, East Java. Furthermore, the problematic soils at liquidity index of 0 - 1.25 are mixed with the ESP in various percentages, i.e. 0%, 10%, 15%, 20%. Several laboratory tests have been conducted to examine the effects of the mixtures, such as index properties, unconfined compressive strength and Scanning Electron Microscopy (SEM). The result indicates that the liquidity index affects the soil stabilized by ESP. SEM test results show that the soil structure changes, it becomes dense on a mixture containing 10% ESP. The conclusion of this research is that the higher the liquidity, the lower the strength.

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Strength Development in Cement Admixed Fine-Grained Dredged Marine Soils

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.802.272 ◽

2015 ◽

Vol 802 ◽

pp. 272-276

Author(s):

Amira Azhar ◽

Chee Ming Chan

Keyword(s):

Bottom Ash ◽

Strength Development ◽

High Plasticity ◽

Fine Grained ◽

Effect Of Water ◽

Curing Period ◽

Binder Ratio ◽

High Plasticity Clay ◽

Water Binder Ratio

Dredged marine soils (DMS) are considered as wastes and are currently not being recycled. Solidification of DMS needs to be undertaken before the materials can be reused.This study focused on the development of strength of three solidified fine-grained DMS which are high plasticity clay (CH), high plasticity silt (MH) and low plasticity silt (ML) admixed with cement and bottom ash. This paper discussed the effect of water-binder ratio and curing period on the strength development of the solidified DMS. The results show that the strength increased with prolonged curing. The strength increased when the water-binder ratio was decreased. CH samples with water-binder (w/b) ratio =1 has the highest strength that are up to 4.7 MPa. Optimal w/b ratio for solidified DMS is w/b=3.

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Influence of Waste Toothbrush Fiber on Strength and Freezing–Thawing Behavior in High Plasticity Clay

Studia Geotechnica et Mechanica ◽

10.2478/sgem-2020-0006 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Fatih Isik ◽

R. Kagan Akbulut ◽

A. Sahin Zaimoglu

Keyword(s):

Clayey Soil ◽

Polypropylene Fiber ◽

Engineering Properties ◽

Waste Materials ◽

High Plasticity ◽

Fine Grained ◽

Reinforcement Material ◽

Fine Grained Soil ◽

High Plasticity Clay ◽

Waste Polypropylene

AbstractThe use of waste materials in civil engineering applications has gained importance nowadays. Consuming limited natural resources and increasing waste disposal costs have led researchers to evaluate waste materials for different geotechnical applications. In this respect, some waste materials are used as reinforcement in soils to improve their engineering properties. The main objective of this paper was to investigate the usability of waste polypropylene fiber as a reinforcement material in high plasticity fine-grained soils. For this purpose, waste toothbrush bristle (WTB) was used as a polypropylene fiber reinforcement material and added to fine-grained soil at ratios of 0.2%, 0.4%, 0.6% and 0.8% by dry total weight. The effect of WTB on freezing–thawing behavior and unconfined compression strength of unreinforced and reinforced clayey soil was evaluated. The results indicated that addition of WTB to high plasticity clay improved its behavior against freezing–thawing. Also, undrained shear strength increases with respect to increment in WTB ratio.

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Volume Change Control of High Plasticity Clay by the Stabilization of Fine-grained Cements

Proceedings of the 2nd World Congress on Civil, Structural, and Environmental Engineering ◽

10.11159/icgre17.178 ◽

2017 ◽

Author(s):

Murat Mollamahmutoğlu ◽

Eyubhan Avcı ◽

Altan Erdem

Keyword(s):

Volume Change ◽

High Plasticity ◽

Fine Grained ◽

High Plasticity Clay

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TWO MODELING APPROACHES FOR REVERBERATION IN A SHALLOW WATER WAVEGUIDE WHERE THE SCATTERING ARISES FROM A SUB-BOTTOM INTERFACE

Journal of Computational Acoustics ◽

10.1142/s0218396x09003847 ◽

2009 ◽

Vol 17 (01) ◽

pp. 29-43 ◽

Cited By ~ 8

Author(s):

CHARLES W. HOLLAND ◽

DALE D. ELLIS

Keyword(s):

Shallow Water ◽

Silty Clay ◽

Sediment Layer ◽

Angle Distribution ◽

Vertical Angle ◽

Fine Grained ◽

Bottom Interface ◽

Grazing Angles ◽

Scattering Kernel ◽

Sediment Interface

In shallow water environments where the uppermost sediment layer is a fine-grained fabric (e.g. clay or silty-clay), the observed reverberation may be dominated by scattering from the sub-bottom. Here, reverberation predictions from normal mode and energy flux models are compared for the case where the scattering arises from a sub-bottom half-space under a fine-grained sediment layer. It is shown that in such an environment, the position of the angle of intromission, in addition to the angular dependence of the scattering kernel, is a factor controlling the reverberation and its vertical angle distribution. It is also shown that the reverberation from a sub-bottom horizon is typically governed by higher grazing angles than the case where the scattering occurs at the water–sediment interface. There was generally very close agreement between the models as a function of frequency (200–1600 Hz), layer thickness (0–8 m), and range (1–15 km). The model comparisons, showing some differences, illuminate the result of different approximations in the two approaches.

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Permeability and volume changes in till due to cyclic freeze/thaw

Canadian Geotechnical Journal ◽

10.1139/t98-015 ◽

1998 ◽

Vol 35 (3) ◽

pp. 471-477 ◽

Cited By ~ 123

Author(s):

Peter Viklander

Keyword(s):

Soil Structure ◽

Void Ratio ◽

Vertical Direction ◽

Rigid Wall ◽

Freezing And Thawing ◽

Volume Changes ◽

Freeze Thaw ◽

Fine Grained ◽

Loose Soil ◽

Freezing And Thawing Cycles

A fine-grained nonplastic till was compacted in the laboratory in three types of rigid wall permeameters, having a volume of 0.4, 1.5, and 25 dm3, respectively, and, was thereafter exposed to a maximum of 18 freezing and thawing cycles. The permeabilities in the vertical direction of saturated samples were measured in unfrozen soil as well as in thawed soil. The results show that the permeabilities changed after freezing and thawing. The magnitude of the changes in this study were in the range 0.02-10 times after freeze/thaw compared with the unfrozen soil. Soil exhibited volume changes subsequent to freeze/thaw. The volume typically decreased for an initially loose soil and increased for a dense soil. Independent of whether the initial soil structure was loose or dense, a constant "residual" void ratio, eres, was obtained after 1-3 cycles. For the soil investigated, the residual void ratio ranged from 0.31 to 0.40.Key words: till, fine-grained, non plastic, permeability, freeze/thaw, residual void ratio.

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Analysis of Three Dimensional Nonlinear Coupled Finite Element Based on some Concrete Rock-Fill Dam

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.998-999.522 ◽

2014 ◽

Vol 998-999 ◽

pp. 522-525

Author(s):

Juan Juan Jin ◽

Min He ◽

Peng Liu

Keyword(s):

Finite Element ◽

Three Dimensional ◽

High Plasticity ◽

Element Analysis ◽

Rock Fill ◽

Arching Effect ◽

Earth Core ◽

Gravel Soil ◽

High Plasticity Clay ◽

The Difference

As the future highest dam in the world, Shuang Jiang Kou rock-fill dam was the water retaining structure of homonymous hydropower station, a controlling engineering on Da Du River hydropower development, which is under design now. This dam is a central earth core dam with a height of 312 meters. A type of gravel soil stiffer than clay, which is made by artificial compounding of clay and gravel, is introduced to reduce the difference in displacement of earth core and rock filled shell zone. Because of the introduced less flexible central core, a more remarkable arching effect of the abutment on earth core might occur simultaneously. A three dimensional coupled nonlinear finite element analysis is carried out to study the three dimensional arching effect of Shuang Jiang Kou rock-fill dam. Computation results show that the arching effect is much notable. Then an innovation is proposed in design, in which a contact high-plasticity clay layer is introduced. It is verified that this innovation is effective and necessary.

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