Particle Size Distribution (Grading)

Particle Size Distribution Analysis

A.D. Envirotech offers particle size distribution (sieving analysis) within our NATA accredited testing facility. We aim to provide the client with a grading result which is representative of the material as a whole. Soil grading is necessary to determine the sheer strength, compressibility and the hydraulic conductivity of the material under examination.

We are accredited to perform:

  • Sampling of material (aggregates) as per AS1141
  • Sieve analysis to AS1289.3.6.1 or RMS T106/T107
  • Foreign Material Testing to RMS T276.


Particle Size DistributionSampling of material

Sampling of material; aggregates and soil from stockpiles is performed by A.D.Envirotech qualified staff using procedures and equipment outlined by Australian Standards series AS1141. These standards ensure that each sample taken provides a representative indicator of all material present within the sampling zone.


Sieve Analysis

Soil and aggregates can be classed as either:

  • Well Graded
  • Poorly Graded


A well graded soil/aggregate will have a distribution of material in all size fractions as it passes from the larger to smaller sieve sizes. This means that a material that is relatively “well graded” will be able to be compacted better than poorly graded soils as there are less air voids within the material when the material is compacted. Thus, a lower hydraulic conductivity exists as there are fewer voids for fluids to fill and consequently pass through the material.

A poorly graded soil/aggregate will have either a uniform distribution (all particles are a similar size) or be gap graded (fractions of materials are missing). A poorly graded material will not compact as successfully as a well graded soil as gaps are created from the missing fractions of soil particles leading to higher hydraulic conductivity.

Sieve analysis is performed is regards to Australian Standard AS1289.3.6.1 or RMS MethodsT106/T107.


Foreign Materials Testing;

Our geotechnical department also conducts foreign materials testing according to RMS T276. For more detail, please refer to ENM Testing