textile reinforced concrete (TRC) 5.04 Flashcards
(technical) textile
-arrangement of multifilament yarns (uni-axial, bi-axial, multi-axial)
-yarns are stretched
-fixing with sewing threads
textile reinforcement - filament and yarn
- Production of filaments: Jet drawing method + sizing (Ø = f (drawing speed))
- Additional protective film (Polymer) (prevents sticking of filaments together, partial “healing” of primary defects)
- Collecting into multifilament yarns (Filaments parallel? Defects?)
- Strength of AR glass filament: 2000 MPa
- Strength of multifilament yarn: 500 MPa (uneven stress distribution)
concrete matrix
- Limitation of the maximum aggregate size
-fine-grained concrete matrix - Good envelopment of the yarns
-low viscosity of the fresh matrix - Specific techniques of TRC
-adjustment of the rheology in the fresh state - Durability of glass fibres
-composition of binder with less OPC
-blended cements (no need of high pH) – more sustainable - Use of fly ash and/or silica fume
-better workability
-refinement of the hydration products and lower
porosity - Higher first crack stress
-Addition of short fibres (hybrid) - Favorable shrinkage and creep behavior
-Regulation of water balance
most traditional production technique for TRC
lamination (wet lay-up) technique
production methods laboratory scale
automated pultrusion
durability of AR glass fiber
Damage of the filament:
* deterioration of sizing in high alkaline environment
* local exposure of the glass “body”, corrosion is possible then filament failure
durability of Yarns Coating
no mayor deterioration due to polymer content
low alkaline matrix (CEM-3 50% OPC) vs high alkaline matrix (CEM-1 100% OPC)
CEM-3 : no deterioration in 180 days
CEM-1:
* The reinforcement is degraded and does not play
any role portlandite
* Large portlandite crystals scratch the fibers
both in accelerated ageing in fog chamber
