The Vibrating Wire Embedment Strain Gauge is used for measuring strain in concrete structures and is suitable for direct burial. Also used in pile tests, load bearing concrete beams and columns, tunnel segments and concrete foundations.
The 150mm long gauge, which is made from stainless steel, may be pre-attached to rebar or by attachment to a 2, 3 or 4 directional rosette, thereby measuring strain in several directions. The gauge comprises a sealed tube containing a wire held in tension between two circular stainless steel pads, one at each end.
Deformation to these pads alters the tension of the wire and the resulting readings are used to measure strain. The changes in strain are monitored by the coil assembly mounted on the gauge. The gauges can also read temperature if required.
The gauges can be read individually or remotely/automatically as part of a data collection system.
- Located within concrete
- Uses proven Vibrating Wire technology
- Suitable for manual or remote monitoring
- Fully waterproof
- Fitted with thermistor for temperature monitoring
- Over 30 years of expertise in the design and manufacture of Vibrating Wire instrument technology
- Accurate, repeatable readings over long cable lengths
- Long working life, long term stability and reliability
- Over-voltage surge arrestor protects against electrical damage
- Connecting cable is screened and flexible
The vibrating wire strain gauge is installed prior to concrete pour and protected during the pour to prevent damage. The gauge may also be pre-cast into a concrete briquette for subsequent casting into the structure, or embedded into holes drilled into an existing structure.
The pickup coil is fitted over a flattened section in the centre of the gauge tube and held in place using a securing clamp; this can be installed on site immediately prior to installation. The sensor is then installed by placing the gauge at a location in the structure suitable for accurately passing microdeformation from the surrounding cured concrete to the gauge.
Cables from the gauges are run to a readout, a terminal box, or a data logging point. The sensor can be read with any commercially available Vibrating Wire readout (or a data logger) and the incorporated thermistor allows for temperature data to be recorded.
The Vibrating Wire Embedment Strain Gauge is designed to measure strain in concrete members on buildings, bridges,dams, pipelines, or any concrete structure.
Typical applications include:
- Concrete members and struts
- Bridges and dams
- Piles and mass concrete
- Strains in reinforcing bars during construction, pile testing and service life