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Particle Density of
Soils
Bulk Density test Particle-size Analysis Aggregate Stability
Analysis
Water Retention Organic Matter Content Analysis of Soil Saturated Hydraulic Conductivity
 

 Particle Density of Soils

Pycnometer


Water Bath machine

Top-load balance
   Particle density of soils refers to the density of the solid particles collectively. It is expressed as the ratio of the total mass of the solid particles to their total volume, excluding pore spaces between particles. Convenient unit for particle density are megagrams per cubic meter (Mg/m3), or the numerically equal grams per cubic centimeter (g/cm3).

   Particle density of a soil sample is calculated from two measures quantities, namely, the mass and volume of the sample. The mass is determined by weighing; the volume, by calculation from the mass and density of water (or other fluid) displaced by the sample.
 

 Bulk Density test

Core sampler


hammer

metallic header
   Soil bulk density is the ratio of the mass of dry solids to the bulk volume of the soil. The bulk volume includes the volume of the solids and the pore space. The mass is determined after drying to constant weight at 105°C, and the volume is that of the sample as taken in the field.

   The method in our laboratory is using core method



 

 Particle-size Analysis
     Particle-size analysis (PSA) is a measurement of the size distribution of individual particles in a soil sample. The major features of PSA are the destruction or dispersion of soil aggregates into discrete units by chemical, mechanical, or ultrasonic means and the separation of particles according to size limits by sieving and sedimentation.

Core sampler

metallic header
1. Sieving
The typical particle size range for sieving is 2000 to 50μm.

Sonicator

Hydrometer

Lowy pipet
2. Sedimentation
Sedimentation analysis relies on the relationship that exists between settling velocity and particle diameter. It include the pipet method and hydrometer method.

(1) Pipet method
he pipet method is often used as a standard method from which other PSA methods are compares.


(2) Hydrometer method
Particle-size analysis can be done conveniently with a hydrometer which allows for nondestructive sampling of suspensions undergoing settling.




 

 Aggregate Stability Analysis- Wet-sieving Method

The wet-sieving shaker
An aggregate is a group of primary particles that cohere to each other more strongly than to other surrounding soil particles. Stability of aggregates is a function of whether the cohesive forces between particles withstand the applied disruptive force.


 

 Water Retention

Sintered glass crucible (for hydraulic head<0.1bar)

   The retention between the soil water content and the soil water suction is a fundamental part of the characterization of the hydraulic properties of a soil. The relationship is identified in the literature by various names, including water retention function, moisture characteristic, and the capillary pressure-saturation curve.





















System for water retention measurement

Pressure chamber


Ceramic Plate


Air Compresso
 

 Organic Matter Content Analysis of Soi
Soil is mainly composed of minerals and organic matter, like decaying plants and animals, as well as living organisms. The organic matter in soil derives from plants and animals. When it decays to the point it is no longer recognizable it is called soil organic matter.

titration pipet

pipe

mortar


safety sucker


magnet




 

 Saturated Hydraulic Conductivity

Apparatus for Measuring Saturated Hydraulic Conductivity
The hydraulic conductivity is a measure of a soil's ability to transmit water. Water movement, whether under saturated or unsaturated conditions, is highly dependent on the hydraulic conductivity.


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