Rock Laboratory

Rock Laboratory

MINTEC starts Rock laboratory consignment since January, 2015. MINTEC uses 1 set of “816 MTS Rock Test” to measure mechanical properties of rock specimens. MINTEC also uses Model 793.10 Multi Purpose Test Ware named FlexTest GT System Software. Our rock laboratory activity series include Preparation, Basic material properties test, Uniaxial Compressive Strength (UCS), Young’s modulus & Poisson’s ratio, Direct shear strength, Triaxial test, Brazilian test, Point load test, Needle Penetration (NPI), and Soil test.

The first step of geotechnical work is to obtain a representative sample of the rock (core sample) related to the right method of geotechnical test. Once this samples (called specimen) are already sampled and collected, they have to be classified, recorded and prepared based on each rock test requirements. 


The next step of preparation is cutting specimen. Specimen has to be cut into appropriate standard size before test. We execute to cut the sample with a cutting machine and not using cutting water. This used to anticipate and prevent weak rocks from any damages during the preparation stage.  After cutted, the specimen is continue to be polished to fulfil the requisite of laboratory methods procedures.

MINTEC owns 1 set of cutting machine and 1 set of polishing machine in order to prepare samples. The specimen preparation work out by of our geotechnical assistant who is capable and understand about the safety requirements and methods in  sample preparation.

Basic material properties test series can only carried out by our laboratory engineer. These test are consist of  determining Water content, Porosity, Density, Absorption and Related properties and Swelling and Slake-Durability Index properties.

Load Frame Assembly (MTS Rock Test System Model 816.02).

MINTEC uses 1 set of “816 MTS Rock Test” that useful for applying and measuring axial load to the specimen. Rock test system was made and designed by MTS in America.

Load Frame Assembly (MTS Rock Test System Model 816.02).

MINTEC uses 1 set of “816 MTS Rock Test” that useful for applying and measuring axial load to the specimen. Rock test system was made and designed by MTS in America.

Uniaxial Compressive Strength (UCS) test intended to measure the uniaxial compressive strength of a rock sample in the form of specimens of regular geometry. This test in mainly intended for strength classification and characterization of intact rock. The UCS of the specimen shall be calculated by dividing the maximum load carried by the specimen during the test by the original cross sectional area.

Uniaxial Compression Test Package for the UCS test consists of Compression Platens and Fore Transducer (Load cell).

This test is the other kind of Uniaxial Compressive test which is useful to discover Young Modulus and Poission Ratio value. Young Modulus & Poisson Ratio Test package used 2 other main component of MTS Rock System, which are Dual axial extensometer and Circumferential extensometer. 

This test measures peak and residual direct shear strength as a function of stress normal to the sheared plane. Results area usually employed in limiting equilibrium analysis of slope stability analysis problems. A shear strength should preferably comprise five tests (minimum three tests). MINTEC uses ELE Portable shear box SL 900 to execute direct shear strength. This test results graphic between Normal stress and Shear displacement.

The purpose of triaxial test is to measure the value of inherent shear strength, cohesion and angle of internal friction, which are used for determination safety factor of slope stability.

Rock Mechanics Laboratory of PT. MINTEC ABADI carries out triaxial test using MTS confining pressure system & ELE Hoek Cell, where the size of sample is NQ (47 mm) and HQ (60 mm) in diameter.  Testing method standard refers to ISRM which suggest that triaxial test is done five times.

MINTEC uses Indirection Tension Package [Model. 643.02A-01] of MTS “816 Rock Test System” to execute Brazilian test.

When first introduced, the point load strength test was used mainly to predict uniaxial compressive strength which was then established test for general-purpose rock strength classification. Point load test now often replaces uniaxial compressive strength in this role since when properly conducted it is as reliable and much quicker to measure.

The point load test strength test is intended as an index test for the strength classification of rocks materials. It may also be used to predict other strength parameters with which it is correlated for example uniaxial tensile and compressive strength.

The Needle penetration test is a non-destructive index test applicable both in the field and laboratory to determine the needle penetration index (NPI) and does not require any special sample preparation. This needle penetration test described in this suggested methods is applied to rock specimens and outcrops to determine the Needle Penetration Index (NPI). This test is suitable for soft sedimentary rocks (0.5 ~ 20 Mpa).

Particle-size analysis of soils test method covers the quantitive determination of the distribution of particle sizes in soils. The distribution of particle sizes larger than 75 µm (retained on the No. 200 sieve) is determined by sieving (Figure (a) sieve Shaker Electric), while the distribution of particle sizes smaller than 75 µm is determined by a sedimentation process, using a hydrometer (Figure (b) Hydrometer analysis) to secure the necessary data.

These test methods cover the determination of the liquid limit, plastic limit, and the plasticity index of soils. Two methods for preparing test specimens are provided as follows:  Wet preparation method and Dry preparation method. The method to be used shall be specified by the requesting authority. If no method is specified, use the wet preparation method.

The liquid and plastic limits of many soils that have been allowed to dry before testing may be considerably different from values obtained on non-dried samples. If the liquid and plastic limits of soils are used to correlate or estimate the engineering behavior of soils in their natural moist state, samples should not be permitted to dry before testing unless data on dried samples are specifically desired.

This test methods covers laboratory compaction methods used to determine the relationship between water content and dry unit weight of soils (compaction curve) compacted in a 4 or 6-in. (101.6 or 152.4-mm) diameter mold with a 5.5-lbf (24.4-N) rammer dropped from a height of 12 in. (305 mm) producing a compactive effort of 12,400 ft-lbf/ft3 (600 kN-m/m3).

Standard Operating Procedures
Working Instructions

Standard Operating Procedures

SOP/MIN/LAB/001. UCS & Brazilian Test
SOP/MIN/LAB/005. Moisture content test
SOP/MIN/LAB/006. Direct shear test

Standard

STD/MIN/LAB/001. Rock lab sampling

Working Intructions

WI/MIN/LAB/001. Basic material property
WI/MIN/LAB/002. Uniaxial Compressive Strength test
WI/MIN/LAB/003. Brazilian test
WI/MIN/LAB/004. Cutting machine
WI/MIN/LAB/005. Polishing machine
WI/MIN/LAB/006. Sample’s diameter measurements
WI/MIN/LAB/007. Molding
WI/MIN/LAB/008. Direct shear
WI/MIN/LAB/009. Needle Penetration Test

External document

ISRM Suggested Methods for Determining Water Content, Porosity, Density, Absorption and Related Properties and Swelling and Slake-Durability Index Properties

SNI 03-1965:1990. Water content test

ISRM Suggested Methods for Determining the Uniaxial Compressive Strength and Deformability of Rock Materials

ISRM suggested methods for determining shear strength

SNI 2825-2008. Uniaxial Compressive Strength

ISRM Suggested Methods for Determining Point Load Strength

ISRM Suggested Methods for the Needle Penetration Test

ASTM Designation: D422 (Reapproved 1998) “Standard test method for practice-size analysis of soils”

ASTM Designation : D 4318 – 00 “Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity index of Soils

ASTM Designation : D 698 – 00a “Standard Test Methods for Laboratory Compaction Characteristis of Soil using Standard Effort (12,400 ft-lbf/ft3(600 kN-m/m3)