Poster Stuctures Vancouver

1
Joining of Ultra High Performance Concrete
(UHPC) Units by Gluing
Dipl.-Ing. C. Muehlbauer Technische Universitaet
Muenchen, Munich, Germany, muehlbauer_at_mb.bv.tum.de
Univ.-Prof. Dr.-Ing. habil. Dr.-Ing. E.h. K.
Zilch Technische Universitaet Muenchen, Munich,
Germany, k.zilch_at_mb.bv.tum.de
Introduction For most applications a fabrication
of UHPC in factories is necessary. There-fore a
basic aspect with building UHPC structures is the
development of elementary joints, which can be
realized at the construction site. A perfect
method of joining UHPC units is gluing the
structural elements with appropriate high
performance adhesives. These are epoxy resin
adhesive and a special reactive powder concrete
(RPC) adhesive. Within the priority programme
SPP1182 of the German Research Foundation
research work on (UHPC) is done since a while. At
the department of concrete structures at the
Technische Universitaet Muenchen there is a
project about gluing UHPC units with these above
mentioned high performance adhesives. This poster
presents the materials, some preliminary
investigations and an outlook to give you an idea
of the project. Materials UHPC Within the
research work a fine-grained UHPC, called M2Q,
with and without steel fibres and with and
without heat treatment was investigated. After
stripping the forms the heat treated UHPC
specimens were carried out to heat treatment for
two days at 90C and afterwards they were stored
under laboratory conditions until they were glued
together.
Reactive powder concrete adhesive (RPC-adhesive)

• Very fine grained UHPC
• Composition basing on M2Q-composition
• Compressive strength after 28d 160 MPa
• w/c-ratio 0.243
• w/b-ratio 0.193
• Processing time about 40 minutes

Shear-compression specimen

• Cold curing epoxy resin adhesive
• Mainly used in construction for strengthening
  concrete and prestressed concrete structures with
  CFRP and steel strips, which are bonded
  externally or glued into slits (near surface
  mounted)
• High cohesion strength and very good adhesion
  property to the adherends
• High compression, tensile and shear strength
• However, the mechanical properties highly depend
  on the temperature at curing time as well as in
  use

Shear-compression strength development

• Summary and Outlook
• Detecting of failure modes of adhesive joints
• Investigation of the long-term behavior of glued
  UHPC joints
• Investigation of the fatigue behavior of glued
  UHPC joints
• Investigation of the influence of steel fiber
  orientation and concentration in the near joint
  surface area
• Developing of failure/design models of adhesive
  joints
• Verifying the design models with tests on
  structural members
• Further information http//www.mb.bv.tum.de

• Glass transition temperature at about 55C
  (curing at room conditions)
• Application of common epoxy resin adhesives for
  strengthening structures is limited in Germany to
  45C
• Alternatives to epoxy resin adhesives?