Site name


Aggregates – coarse, small and fine fillers

The Testing Laboratory Directorate (TLD) is accredited to perform testing of aggregates for various uses – concrete aggregates; rock materials for bituminic mixtures and road pavements, airport runways and other transport areas; light concrete aggregates, solution and injection solution, solution aggregates; rock materials for unbound and hydraulically bound materials used in construction facilities and road construction; crushed stone for railways; rock materials for hydraulic construction.
The Laboratory performs geometrical, physical, thermal and chemical tests of a wide variety of construction products by characteristics, determined in European harmonized standards.
The laboratory issues test reports, normalized in accordance with the requirements of the harmonized standards.
The testing equipment is delivered from acknowledged manufacturers and provides the quality of the analyses.
The main characteristics, which are tested are: granulometric content, grain shape, percentile content of grains with fragmented and crushed surfaces, shell content, sand equivalent, methylene blue test, determination of resistance to wear (micro-Deval), determination of resistance to fragmentation, loose bulk density and voids, grain density and water absorption, determination of resistance to freezing-thawing, testing with magnesium sulphate.
The main chemical characteristics, which are determined are: water-soluble and acid soluble sulphates, total sulfur, water soluble chlorine salts using Mohr’s methods, humus presence, determination of water solubility, low weight contaminants, determination of carbon, metal content.
TLD also performs diagnostics of mineral composition (qualitative and quantitative X-Ray Diffraction analysis) and petrographic analysis, and these activities are beyond TLD’s scope of accreditation.

If the client requires it, the test reports can also be issued both in Bulgarian and in English.