Concrete Technology


Dr.-Ing. Thomas Kränkel

The following services are offered for the preparation of specimens and the determination of the characteristic values of fresh concrete:

  • Concrete mixers (capacity: 25, 60, 100 litres)
  • Intensive mixer (capacity 45 litres)
  • Consistency (flow spread, slump and compaction test), air void content, fresh concrete density
  • Water content (drying test)
  • J-ring test
  • L-box test
  • Segregation test
  • Rheometrical investigations with paste or mortar
  • Control sieving of washed-out aggregate
  • Water demand according to Puntke
  • Specimen storage in standardized conditions or with specified temperature regimes

Investigation of mechanical properties:

  • Porosity and pore size distribution with mercury intrusion porosimetry
  • Particle size distribution with laser granulometry
  • Static pressure Young’s modulus at up to 4 MN upper load
  • Uniaxial compressive strength, splitting tensile strength, controlled by deformation or load up to 4 MN upper load
  • Flexural strength, controlled by deformation or load up to 500 kN upper load
  • Tensile strength, controlled by deformation or load up to 500 kN upper load (in dependence of specimen geometry)
  • Fatigue testing (flexural, uniaxial compression/tension) up to 500 kN upper load (frequency depends on specimen deformation)
  • Adhesive strength
  • Resistance to water penetration
  • Freeze-thaw and freeze-thaw deicing salt resistance according to cube, CDF or CIF tests
  • Characteristic values for air voids in hardened concrete

Special tests:

  • Concrete additions (silica fume, fly ash)
  • Concrete admixtures
  • Thermal coefficient of expansion
  • Diffusion resistance
  • Carbonation depth
  • Determination of autogenous and drying shrinkage in different storage climates
  • Adiabatic calorimetry with concrete
  • Cracking tendency according to RILEM TC 119-TCE in the rigid cracking frame (control test)
  • Measurement of micro and macro surface texture with a 3D laser scanner
  • Determination of electrolytic resistance (Wenner measurement, multi-ring electrode method)
  • Determination of anchor length of prestressing steel in concrete (tensioning force test static/dynamic)

Further special tests are available upon request.

Construction site investigations / surveillance:

  • Performance of control tests, surveillance of construction measures according to DIN 1045-3, initial testing, proof of conformity
  • Checking factory production control, performance of self-monitoring
  • Core extraction at horizontal and vertical surfaces

Further construction site investigations are available upon request