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Concrete free deformation at early age

 

General Information

Location:

BATir - Building, Architecture & Town Planning, building : C, local : Technical

Key words:

Early age / Autogenous shrinkage

Main application:

The determination of the autogeneous shrinkage is carried out on a test rig composed by a corrugated PVC mould immersed inside a temperature controlled bath (Lauda). External transducer measures the vertical displacement of the upper head of the specimen while the specimen is placed vertically. A thermocouple embedded in the core of the specimen measures the concrete temperature variations. The test rig contains a thermo-statically controlled water bath, a conditioning box and a PC in addition to the rig and the container. The measurements can start no more than one hour after the concrete batching. The autogeneous deformations are recorded from the time to, roughly equal to the setting time. The deformations before setting depend strongly on the test friction conditions. Typically, the usual test is carried out in isothermal conditions (20°C), without external moisture exchange (the upper part of the mould is sealed by a cap equipped with a toric joint) and at the atmospheric pressure (when the internal pressure differs from the atmospheric pressure of a value higher than 0.05 bar, the pressure equilibrium is provided by a valve fixed on the cap). This test rig measures the displacement of the upper head of the specimen but the measurement must be initialized since setting time, a specific time determined by a parallel experimental method: an ultrasonic waves transmission measurements method, the FreshCon system.

Contact details

Stéphanie Staquet

Associate Professor – Chargée de cours 

Service BATir - Building, Architecture & Town Planning  

Université Libre de Bruxelles  ULB

87, A.Buyl Avenue CP194/4

1050 Bruxelles (Belgium)

Tél:+32 2 6502758

Fax:+32 2 6502782

courriel: sstaquet@ulb.ac.be

http://batir.ulb.ac.be/research/lgc-civil-engineering.html

 Instrument specification

Quantity :

2

 Composed by :

-          Lauda Ecoline satredition 6 L

-          3 PT 100

-          External transducer to measure the displacements

-          3 Moulds

 



Quantity: 2