1.Construction Testing Center of "TPA" Ltd., Sofia

TPA International (Technische Püfanstalt) with its headquarters Austria is a service company to STRABAG SE with the main purpose of providing quality and innovation in the construction sector.

It is represented in 12 European countries with a functioning network of more than 100 laboratories with more than 600 associates.

TPA International is represented in Bulgaria by TPA Ltd. Which has two testing laboratories, the Construction Testing Center (CTC), Sofia and Burgas. Since August 2003 the CTC of TPA Ltd. has been the successor of the Central Construction Laboratory of INGSTROY AD Sofia. The CTC of TPA Ltd., Sofia is an accredited laboratory for testing and sampling as follows: cement, aggregates for concrete; aggregates for bituminous mixtures and surface treatments for roads, airfields and other trafficked areas; aggregates for unbound and hydraulically bound materials for use in civil engineering work and road construction; mortars and asphalt concrete mixtures; concrete and reinforced concrete products; bitumen and bitumen emulsions and pastes; asphalt-concrete mixtures; concrete products, soils and etc. At present, the laboratory works with over 50 construction companies on the Bulgarian market.

The CTC has a permanent highly competent staff for sampling and testing within the scope of accreditation. Four of the employees have extensive experience in designing concrete and asphalt mixes, as well as servicing of production plants for concrete, concrete products, asphalt mixtures and aggregates.

CTC of TPA Ltd., Sofia is also used as an independent third-party testing laboratory.

2.Independent Construction Laboratory at Transport Infrastructure and Construction Institute

3.University Construction Testing Laboratory at the University of Architecture, Civil Engineering and Geodesy Center for Research and Design Ltd., Sofia

4.Costuction Laboratory by „BKS – Gorna Oriahovica” АD, town Gorna Oriahovica