VOLUME CHANGE OF COMPACTED CLAY SOIL AGGREGATES

Soil Science ◽  
1968 ◽  
Vol 105 (2) ◽  
pp. 106-111 ◽  
Author(s):  
R. K. CHANG ◽  
B. P. WARKENTIN
Keyword(s):  
Volume Change ◽  
Clay Soil ◽  
Soil Aggregates ◽  
Compacted Clay

Some factors affecting compacted clay swelling

1970 ◽  
Vol 7 (1) ◽  
pp. 79-91 ◽  
Author(s):  
A. Yevnin ◽  
D. Zaslavsky
Keyword(s):  
Moisture Content ◽  
Volume Change ◽  
Empirical Equation ◽  
Clay Soil ◽  
Initial Density ◽  
Initial Moisture Content ◽  
Swelling Pressure ◽  
Compacted Clay ◽  
Factors Affecting ◽  
Applied Loading

Volume change after saturation was determined on specimens of a statically compacted clay soil. It was found that density after swelling increases linearly with increasing initial density, initial moisture content, and increasing logarithm of applied loading pressure. An empirical equation with five coefficients and a constant, found with the aid of a computer, represents the results with a coefficient of correlation close to 1. An equation for the swelling pressure was also obtained from this equation. Results of specimens which consolidated did not fit the lines obtained for swelling. The relationships obtained were explained by the influence of particle reorientation and moisture content on swelling tendency.

scholarly journals Effects of Initial Water Content on Microstructure and Mechanical Properties of Lean Clay Soil Stabilized by Compound Calcium-Based Stabilizer

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1933 ◽  
Author(s):  
Chenglong Yin ◽  
Wei Zhang ◽  
Xunli Jiang ◽  
Zhiyi Huang
Keyword(s):  
Water Content ◽  
Soil Stabilization ◽  
Clay Soil ◽  
Soil Aggregates ◽  
Optical Microscope ◽  
Initial Water Content ◽  
Reaction Products ◽  
Unconfined Compression Test ◽  
Initial Water ◽  
X Ray

Initial water content significantly affects the efficiency of soil stabilization. In this study, the effects of initial water content on the compressibility, strength, microstructure, and composition of a lean clay soil stabilized by compound calcium-based stabilizer were investigated by static compaction test, unconfined compression test, optical microscope observations, environment scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The results indicate that as the initial water content increases in the range studied, both the compaction energy and the maximum compaction force decrease linearly and there are less soil aggregates or agglomerations, and a smaller proportion of large pores in the compacted mixture structure. In addition, for specimens cured with or without external water supply and under different compaction degrees, the variation law of the unconfined compressive strength with initial water content is different and the highest strength value is obtained at various initial water contents. With the increase of initial water content, the percentage of the oxygen element tends to increase in the reaction products of the calcium-based stabilizer, whereas the primary mineral composition of the soil-stabilizer mixture did not change notably.

scholarly journals Soil Compaction Methods Development

2018 ◽  
Vol 7 (3.2) ◽  
pp. 636
Author(s):  
Tetyana Lvovska ◽  
Tetyana Lytvynenko ◽  
Alla Kariuk
Keyword(s):  
Soil Compaction ◽  
Clay Soil ◽  
Statistical Processing ◽  
Field Tests ◽  
Water Migration ◽  
Compacted Clay ◽  
Empirical Dependence ◽  
Compaction Test ◽  
Methods Development ◽  
Proctor Test

A process of soil compaction methods development including new authors’ methodology is described. The importance of soil compaction for engineering purposes is substantiated. Preconditions for Proctor compaction test appearance are highlighted. Proctor’s approach and suggestions for the degree of soil compaction assessing are analyzed. Soviet version of Proctor’s equipment and Modified Proctor compaction test are given. Principal differences between Proctor test, Standard compaction test and Modified Proctor test are presented. The problems and disadvantages of existent soil compaction tests are revealed. New authors’ physical experiment methodology for patterns establishment of water migration in subgrade embankment depth, in the capacity factors of what it is accepted: clay soil type (its number plasticity); moisture, at what the soil was compacted; soil skeleton density; embankment height; «rest» time after subgrade erection and before it’s operation is developed and realized. By laboratory and field tests water migration patterns in compacted subgrade soils depth are established. As a result of statistical processing of research results, the empirical dependence of compacted clay soil stabilized moisture is obtained. Empirical dependence parameter corresponds to maximum molecular moisture capacity at what it is advisable to do the subgrade clay soils multilayer consolidation for their long-term strength ensuring. 

Role of Soil Structure and Matric Suction in Collapse of a Compacted Clay Soil

2003 ◽  
Vol 26 (1) ◽  
pp. 9058 ◽  
Author(s):  
L David Suits ◽  
TC Sheahan ◽  
SM Rao ◽  
K Revanasiddappa
Keyword(s):  
Soil Structure ◽  
Clay Soil ◽  
Matric Suction ◽  
Compacted Clay

New Brazilian species of Folsomides Stach (Collembola: Isotomidae)

Zootaxa ◽  
2020 ◽  
Vol 4896 (3) ◽  
pp. 443-450
Author(s):  
MARIA CLEIDE DE MENDONÇA ◽  
ANA CAROLINA DA ROCHA NEVES
Keyword(s):  
New Species ◽  
Rio De Janeiro ◽  
Clay Soil ◽  
Botanical Garden ◽  
Compacted Clay ◽  
Brazilian Species ◽  
Janeiro City

A new blind species, Folsomides cariocus sp. nov., which belongs to the F. parvulus group sensu Fjellberg (1993), is described and illustrated based on material collected in compacted clay soil covered by undergrowth and no litter around the bee nest holes at the Botanical Garden, located in Rio de Janeiro City. The new species is very similar to F. parvulus Stach, 1922 but differs mainly due to the absence of eyes. Synonymies based on ocular variations and pigmented spots were discussed and a table for the group parvulus species is present. 

Interpretation of electrical conductivity in a clay soil containing salts

Soil Research ◽  
1978 ◽  
Vol 16 (3) ◽  
pp. 311 ◽  
Author(s):  
AV Blackmore
Keyword(s):  
Electrical Conductivity ◽  
Clay Soil ◽  
Soil Aggregates ◽  
Exchangeable Cation ◽  
Simple Relationship ◽  
Stable Range ◽  
Soil Electrical Conductivity ◽  
Salt Exclusion ◽  
Exclusion Mechanism ◽  
Soil Conductivity

The use of directly measured electrical conductivity of soil to provide an index of soil salinity is discussed. It is suggested that if an anion exclusion mechanism within the microfabric of a wet clay soil can lead to a non-uniform, but stable, range of salt concentrations, then the validity of such an index would be jeopardized. Experiments involved the monitoring of soil electrical conductivity during leaching and diffusion of salts from stable clay-soil aggregates packed in columns and cells. The equilibrium values of conductivity are inversely related to exchangeable cation valence, but are not affected by the type of anion involved. The soil conductivity was often much smaller than the value inferred from the amount of salts actually extracted from the columns or contained in the small isolated electrical conductivity cells. The results are consistent with the operation of a salt exclusion mechanism in the smaller pores of the soil fabric. With monovalent cations and relatively low electrolyte concentrations, the trapping of salts within the microfabric is maximized, while in contrast, with aluminium and aged hydrogen clays the exclusion effect is almost completely suppressed, in accord with double-layer theory. If salts are retained against concentration gradients within the fine structure units of the soil, current-transmitting regions between the units are of correspondingly high resistance, and this is reflected in a soil electrical conductivity value that is low relative to the amount of electrolyte between the electrodes. The observed soil conductivity may, however, bear a simple relationship to the salt fraction of the soil actually 'available' to plant roots.

scholarly journals Lack of Response of Some Food Crops to the Application of Synthetic Soil Conditioners to A Clay Soil in Lajas Valley

1969 ◽  
Vol 41 (3) ◽  
pp. 167-172
Author(s):  
M. A. Lugo-López ◽  
J. A. Bonnet ◽  
M. Rico-Ballester ◽  
G. Acevedo
Keyword(s):  
Field Experiment ◽  
Physical Properties ◽  
Clay Soil ◽  
Water Movement ◽  
Soil Aggregates ◽  
Soil Physical Properties ◽  
Food Crops ◽  
Dry Powder ◽  
Soil Conditioners ◽  
The Stability

Data are presented here from a field experiment where Krilium 6 and 9, Aerotil, and Goodrite (dry powder of the first three and flakes of the fourth) were applied to the uppermost 6 inches of a Santa Isabel clay soil at the Lajas Valley, each at rates of 900, 1,800, and 3,600 pounds to the acre. Three crops: Tomatoes, white beans, and sweetpotatoes, were grown in the sequence following the establishment of the treatment differentials. None of the crops showed any response to the soil-conditioning chemicals. The stability of the soil aggregates of Santa Isabel clay, which is naturally high, was not affected by the treatment. The data presented show also that the water movement and retention and other soil physical properties remain unaffected by treatment. The lack of response is discussed and compared with other problem soils where crop responses have been measured.

Sign in / Sign up

Export Citation Format

Share Document