Our testing laboratory is an integral part of the geotechnical investigation and geological
study. AKMG laboratory has been managed by highly qualified material engineer and
laboratory technicians for carrying out the routine and special tests according to ASTM &
AASHTO standards. Our laboratories are equipped to provide comprehensive soil test,
rock test, aggregates and concrete test.
Through our in-house laboratory we are able to perform following tests:
A sieve analysis (or gradation test) is a practice or procedure used (commonly used in civil
engineering) to assess the particle size distribution (also called gradation) of a granular
material by allowing the material to pass through a series of sieves of progressively
smaller mesh size and weighing the amount of material that is stopped by each sieve as a
fraction of the whole mass.
The Atterberg limits are a basic measure of the critical
water contents of a fine-grained soil: its shrinkage
limit, plastic limit, and liquid limit. Depending on its water
content, a soil may appear in one of four states: solid,
semi-solid, plastic and liquid. In each state, the
consistency and behavior of a soil is different and
consequently so are its engineering properties. These
limits were created by Albert Atterberg ,
a Swedish agriculturist in 1911. They were later refined
by Arthur Casagrande.
- Shrinkage limit
- Plastic limit
- Liquid limit
Specific gravity is the ratio of the density (mass of a unit volume) of a substance to the
density of a given reference material.
For fine aggregates: (ASTM C128 – 15)
The test methods cover the determination of the specific
gravity of soil solids that pass the 4.75-mm (No. 4) sieve, by
means of a water pycnometer. The OD specific gravity is
determined after drying the aggregate. The SSD relative
density and absorption are determined after soaking the
aggregate in water for a prescribed duration.
For coarse aggregates: (ASTM C 127)
Aggregate specific gravity is a measure of a material’s
density (mass per unit volume) as compared to the
density of water at 73.4°F (23°C). Therefore, by
definition, water at a temperature of 73.4°F (23°C) has a
specific gravity of 1.
The mass of a coarse aggregate sample is determined
in SSD, oven-dry and submerged states. These values
are then used to calculate bulk specific gravity, bulk
SSD specific gravity, apparent specific gravity and absorption.
Consolidation Test is used to determine the rate and magnitude of
settlement in soils. The settlement values obtained by this test are
due to primary consolidation only which is 90% of the total
consolidation. The results of consolidation test are very much helpful
in the design of foundations. The testing is usually done with
consolidometer or odeometer.
A direct shear test is a laboratory or field test used by geotechnical engineers to measure
the shear strength properties of soil or rock material, or of discontinuities in soil or rock
A Direct shear test or Box shear test is used to determine the shear strength of the soil. It
is more suitable for cohesionless soils.
For Rocks ASTM D7012-14e1, (2014)
The Unconfined Compression Test is a laboratory test used to derive the Unconfirmed
Compressive Strength (UCS) of a rock specimen. Unconfirmed Compressive Strength
(UCS) stands for the maximum axial compressive stress that a specimen can bear under
zero confining stress. Due to the fact that stress is applied along the longitudinal axis, the
Unconfined Compression Test is also known as Uniaxial Compression Test. UCS is a
parameter widely used in geotechnical design, but may not represent the strength in-situ.
On a large scale, the rockmass properties are highly affected by other factors including
discontinuities, faults and weathering.
During the test, apart from the axial load, axial and lateral deformation are commonly
measured to derive the sample’s elastic modulus and Poisson’s ratio.
The Point load test is an index test by which the rock is
classified according to the strength. The test can be used to
estimate other characteristics of intact rocks with which it
correlates, such as uniaxial compressive and
After certain sample dimensions are determined, the
sample is loaded with uniformly increasing force so that the
brake occurs within a period of between 10 and 60 seconds.Usually, no preparation of
samples for testing is required which allows for on site testing. The orientation of
anisotropic samples of intact rocks during the test in relation to the load direction can be:
• Vertical to debilitation surfaces
• Parallel to debilitation surfaces
In situations where an irregular break occurs due to sample inhomogeneity, the test should
be considered invalid.
The Point load test (PLT) is an extremely fast and efficient way to determine and
classify the strength of an intact rock.
The compression test shows the best possible strength concrete can achieve in perfect
conditions. The compression test measures concrete strength in the hardened state. Field
concrete samples are prepared, cured and tested according to ASTM standard
procedures. Specimens are prepared from concrete taken from different construction sites.
Following processes and calculations are used for measuring compressive strength of
cylindrical concrete specimens
Triaxial tests are widely used in geotechnical engineering both in soil and rock mechanics.
Specimens are axially loaded to failure while a confining pressure is constantly applied. As
a result, the behavior of geomaterials is investigated in a three-dimensional stress state.
The principal stresses (the maximum and minimum normal stresses acting on a plane at
which the shear stress is zero) in 3-dimensional objects are three (σ1> σ2> σ3). In nature,
the principal stresses may differ. However, in laboratory triaxial tests, the intermediate
stress σ2 is equal to σ3. Conducting laboratory tests in which all applied principal stresses
differ is challenging and is not widely used. Such a procedure would be referred as
polyaxial or true triaxial test. Moreover, research has shown that the effect of the
intermediate stress is minor. There are several variations of the triaxial test:
Consolidated drained (CD)
In a ‘consolidated drained’ test the sample is consolidated and sheared in compression
slowly to allow pore pressures built up by the shearing to dissipate. The rate of axial
deformation is kept constant, i.e., strain is controlled. The idea is that the test allows the
sample and the pore pressures to fully consolidate (i.e., adjust) to the surrounding
stresses. The test may take a long time to allow the sample to adjust, in particular low
permeability samples need a long time to drain and adjust strain to stress levels.
Consolidated undrained (CU)
In a ‘consolidated undrained’ test the sample is not allowed to drain. The shear
characteristics are measured under undrained conditions and the sample is assumed to be
fully saturated. Measuring the pore pressures in the sample (sometimes called CUpp)
allows approximating the consolidated-drained strength. Shear speed is often calculated
based on the rate of consolidation under a specific confining pressure (whilst saturated).
Confining pressures can vary anywhere from 1 psi to 100 psi or greater, sometimes
requiring special load cells capable of handling higher pressures.
Unconsolidated undrained (UU)
In an ‘unconsolidated undrained’ test the loads are applied quickly, and the sample is not
allowed to consolidate during the test. The sample is compressed at a constant rate
The following chemical tests are carried out on soil and ground-water samples
Total dissolved solids (TDS)