Feasibility of concrete prestressed by shape memory alloy short fibers

Title: Feasibility of concrete prestressed by shape memory alloy short fibers
Author(s): K. Moser, A. Bergamini, R. Christen, C. Czaderski
Paper category : journal
Serial title: Materials and Structures
Abreviated Serial title: Mater. Struct.
ISSN: 1359-5997
Publisher: RILEM Publications SARL
Volume: 38
Issue: 279
Issue date: 2005-06-01
Publication year: 2005
Pages: 593 - 600
Total Pages: 8
Nb references: 27
Language: English

Abstract: Mortar and concrete exhibit low tensile strengths.
Hence, cracks develop easily due to shrinkage and external actions.
They can be prevented by applying prestress, thus obtaining crack-free products.
Such products exhibit a high bending and tensile strength, are leak proof and of high durability.
Prestress can be realised using external or internal wires or cables.
In thin walled products, however, this is not feasible.
For this purpose, short fibres of shape memory alloy (SMA) wires were embedded in mortar.
The wires had been shaped by inelastic elongation into loopand starshaped fibres.
After hardening of the mortar, the specimens were heated up in order to activate the tensile stress in the fibres, thereby causing a prestress of the surrounding mortar.
The effect was monitored by length measurements both on specimens with and without fibres.
Compression stresses in the cement mortar were estimated by multiplying the difference in strain between fibre-reinforced and reference prisms by the Young’s modulus.
Thus, compression up to 9 MPa was reached in the experiments.
For practical applications, alloys with suitable temperature domains of austenitic and martensitic transformation, most likely Fe-based, and efficient methods for the production of such fibre mortars are to be developed.

Online publication: 2005-03-09
Classification: Scientific Reports
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/14327