Concrete material use strain gauges

Strain gauges for surface measurements on concrete and mortar

Strain gauges for concrete are designed to measure mechanical strain on the surface of concrete, mortar and other suitable construction materials. Unlike conventional gauges intended primarily for metal components, these strain gauges are available with longer measuring grids and constructions adapted to the characteristics of cement-based materials.

Althen offers P and PL Series strain gauges for general surface measurements, alongside FLM and WFLM Series models with stainless steel backing. The WFLM Series also includes additional moisture protection and integrated lead wires for demanding measurement conditions.

Why is gauge length important when measuring concrete strain?

Concrete is a heterogeneous material consisting of cement paste, aggregates and pores. Local strain can vary considerably across its surface. A longer gauge length can help measure strain over a more representative section of the material, rather than capturing only a highly localized response.

The appropriate gauge length depends on the aggregate size, surface condition and measurement objective. For example, a gauge intended to measure average surface strain may require a different length from one used to investigate local deformation.

When should you use surface-mounted concrete strain gauges?

Surface-mounted strain gauges can be considered for:

• Concrete and mortar material testing under mechanical loading.
• Strain measurements on existing concrete components and structures.
• Laboratory testing of concrete specimens and structural elements.
• Structural monitoring applications where surface strain is an important measurement parameter.

For measurements inside concrete or mortar, consider strain gauges specifically designed for embedding during casting.

What should you consider when selecting a concrete strain gauge?

• Gauge length: Select a measuring length suitable for the material's aggregate structure and the desired measurement resolution.
• Surface preparation: Ensure the concrete surface is sufficiently stable, clean and suitable for the specified bonding procedure.
• Moisture exposure: Consider whether the measurement requires additional protection against moisture or water.
• Measurement duration: Distinguish between short-term material testing and longer-term structural monitoring.
• Gauge configuration: Choose single-axis or multi-axis measurement configurations according to the expected strain directions.
• Installation and wiring: Select suitable adhesives, protective materials and lead-wire arrangements for the test conditions.

Always consult the individual product datasheet for gauge dimensions, operating conditions and recommended installation materials.