Curriculum Vitae for Kristian Hertz - Danmarks Tekniske Universitet

Curriculum Vitae
Kristian Hertz
21
2005-11-14
Research results obtained by Kristian Hertz:
Develops an object oriented EDP method for calculation of force distributions in shear walls and
plates modelled by two crossing systems of stringers combined by shear membranes. The
method can be applied on folded and connected walls and plates and in practise it has proven to
be much cheaper and easier to apply than traditional finite element programs.
Invents a patented machine capable of utilising the power of sea waves.
Creates a set of concepts and a cognitive structure based on the theory of sets and Empiricism.
Using this for a logical representation of building design data in a CAD system, and develops a
number of versions of an object-oriented program for conceptual modelling for UNIX and
Windows with interface to AutoCAD and a separate user interface.
Makes the first coherent description of the mechanical and chemical changes of concrete
subjected to high temperatures based on a comprehensive literature study of 500 references and
300 test series supplemented by own test results.
A new method for testing the bond strengths of variable reinforcing bars in variable concretes
and in fire damaged concretes. Finds that the bond strength can be calculated for reinforcement
of sufficient corrugation.
A calculation model for the anchorage strength of reinforcement as a minimum of the bond
strength and a splitting strength, which depends entirely on the cross section. The method gives
up to 10-20 times less anchorage lengths than the codes prescribed, and for the first time it
offered an explanation to the short anchorage lengths observed to be necessary for slabs in tests
and practise.
Explains why an effectiveness factor is needed for shear design and how it depends on the cross
section.
Discovers how concrete specimens can be heated to more than 1000°C in a microwave oven
without giving rise to thermal stresses, which until then had spoiled any attempt on finding the
mechanical properties of rapid heated concrete.
Finds for the first time how the mechanical properties changes for concrete heated rapidly.
Develops a fireproof concrete based on Danish raw materials.
Finds as the first that high strength concrete densified by micro-silica has an increased risk of
explosive spalling, even at slow heating rates.
Finds that thermal stresses from hindered thermal expansion can be a precondition for explosive
spalling of certain dense concretes.
Develops a new test method capable of deciding whether a concrete may have a spalling problem
for hindered thermal expansion by means of a standard cylinder.
Finds that melamine based superplasticizing additives can give toxic gases like ammonia when
heated.