Dr.-Ing. Johannes Büchner

Univ.-Prof. Dr.techn. Michael P. Wistuba

Bitumen Competence Center (BKZ)
c/o Institut für Straßenwesen
Beethovenstraße 51 b
38106 Braunschweig
bkz@itubs.de

The BKZ

The Bitumen Competence Center (BKZ) researches and tests bitumen, bituminous binders, bituminous compounds and other bitumen-bound building materials for the construction industry. The main areas of application are road construction, sealing and landfill technology as well as hydraulic engineering.

Our activities are characterized by a strong focus on application and a materials science approach. In basic research, the BKZ cooperates closely with the Technical University of Braunschweig.

We advise on material technology, testing, application-related and development-related issues. Our cooperation partners include the construction and building materials industry, trade associations and road construction authorities in Germany and abroad. We prepare research reports and expert opinions, carry out material studies, accompany product development, support the proof of suitability as well as the market launch and provide assistance with questions regarding product validation, material control and quality assurance.

We use a variety of different test methods for material characterization. This includes standardized tests in accordance with national and international regulations, as well as our own developments, particularly for rheological material characterization (flow and deformation behaviour). For example, the use of the dynamic shear rheometer at the BKZ has been extended to include the possibility of a holistic description of the rheological behavior of bitumen and bituminous binders as well as mixtures with fine aggregates (mastic).

We are actively involved in national and international expert committees, including

  • FGSV AA 7.2 “Binders” and FGSV AK 7.2.1 “Bitumen and modified bitumen”,

  • FGSV AK 7.6.2 “Mortar components”,

  • DIN NA 062-03-32 GA “Bitumen; test methods and requirements for binders”,

  • CEN TC 336 WG 1 “Bituminous Binders for Paving”,

  • RILEM Cluster F “Bituminous Materials and Polymers”: including TC FBB “Fingerprinting of Bituminous Binders”.

Equipment

  • Dynamic shear rheometers (DSR)

    • Kinexus Pro+ from Netzsch with low-temperature option
    • Kinexus Pro from Netzsch with low-temperature option
    • Kinexus DSR+ from Netzsch with low-temperature option
    • Kinexus DSR from Netzsch
    • MCR 702 from Anton Paar with low temperature option & convection oven
    • Gemini II from Bohlin

  • Bending beam rheometer (BBR)

    • TE-BBR from Cannon
    • TE-BBR Pro from Cannon

  • Rolling-Thin-Film-Oven-Test (RTFOT)

  • Pressure Ageing Vessel (PAV)

  • Asphalt analyzers for binder recovery using Tri, Per, OME

  • Manual binder extraction using Tri, Per, OME, Toluene

  • Laboratory stirrer (IKA MINISTAR 20) and dissolver (DISPERMAT CA40)

  • Softening point ring and ball

  • Needle penetration

  • Breaking point according to Fraaß

  • Ductilometer (elastic recovery, force ductility)

  • Flash point

  • Rolling bottle test

Picture credits: Dr.-Ing. Johannes Büchner

Services

  • Bitumen and bituminous binders
  • Bitumen from asphalt granulate
  • Bitumen-filler mixtures (mastic)
  • Unknown binder samples
  • Bitumen emulsion
  • Blended or fluxed bitumen
  • Polymer bitumen
  • Bitumen compounds for roofing membranes
  • Bituminous joint sealants
  • Composites up to particle size 2 mm

  • Polymers
  • Grow
  • Fibers
  • Rubber
  • Rejuvenators/rejuvenating agents
  • Biogenic additives
  • Bio-based binders
  • Nanoparticles
  • Substances authorized according to REACH – Regulation (EC) 1907/2006

  • Conventional binder characteristics
  • Viscoelastic properties (complex shear modulus and phase angle)
  • Flow behavior (viscosity)
  • Bending creep behavior
  • Creep and recovery behavior
  • Relaxation behavior
  • Fatigue & Healing
  • Usage properties (performance)
  • Thixotropic properties
  • Stiffening effect of filler
  • Aging behavior

  • Product classification according to national/international regulations
  • Determination/characterization Binder
  • Assessment of service behavior (as a component, in asphalt)
  • Evaluation of the effectiveness of additives
  • Determination of performance grade
  • Creation of binder design (as part of asphalt reuse)
  • Visualization of the results
  • Statistical evaluation
  • Modeling material behavior, e.g. using a CAM model or 2S2P1D model

  • Plate-plate measuring system with 4, 8, 20 and 25 mm diameter
  • Plate-cone measuring system with 40 mm diameter
  • Coaxial cylinder measuring system with 28 mm diameter
  • Solid body clamping for prismatic test specimens
  • Paddle stirrer
  • Rheological testing in the entire relevant temperature range from -40 to +200 °C.
  • Rheological testing in oscillation mode, rotation mode and creep mode (amplitude sweep, temperature sweep, temperature-frequency sweep, frequency sweep, time sweep, shear rate sweep)
  • Standardized tests in accordance with German regulations:
    • AL DSR examination (BTSV)
    • AL DSR test (MSCRT)
    • AL DSR test (T-Sweep)
    • AL DSR test (constant shear rate)
    • DIN 52050
  • Standardized tests in accordance with European regulations:
    • EN 14770
    • EN 16659
    • prEN 14023
    • prEN 17643
  • Standardized tests of international regulations (selection):
    • AASHTO T 315-12
    • AASHTO T 350-14
    • AASTHO TP 123-16
    • AASHTO TP 101-14
    • ASTM D7175-15
    • ASTM D7405-15
    • ASTM D8189-19
    • ASTM D7552-09

Further information can be found on the Institute’s website: https://www.tu-braunschweig.de/isbs