Free GPR Datasets for Concrete Inspection

GPR for reinforced concrete

High-frequency electromagnetic waves reflect on rebar and material interfaces, producing characteristic hyperbolic signatures on the radargram. GPR is non-destructive, gives immediate results, and involves no radiation — making it deployable on active construction sites without safety perimeters. It complements traditional methods like core drilling and ultrasound testing by providing continuous coverage rather than point measurements.

Rebar detection

Each rebar produces a hyperbolic reflection whose apex marks the bar location. Modern GPR software (including GPRviewer) can automatically pick these hyperbolas to determine rebar position, cover depth (with 2-3% accuracy in typical conditions), spacing, and orientation. This is critical for safe pre-drilling operations, structural audits verifying compliance with standards like EN 1992-1-1 or ACI 318, and forensic investigations of existing structures.

Concrete thickness measurement

By analyzing the two-way travel time of the GPR signal reflected from the back of a slab or wall, and knowing the dielectric permittivity of concrete, thickness can be measured to ±5% accuracy at typical depths of 30-40 cm. This is essential for quality control on new construction, retrofit design calculations, and structural modeling of existing buildings.

Voids and defects

Air voids, delaminations between concrete layers, honeycombing, and localized moisture zones each create distinctive signal signatures on the radargram. Voids produce strong reflections with polarity reversals, while delaminations create characteristic multiple reflections. Early detection of these defects prevents structural failures and informs repair strategy — spot injection, targeted demolition, or monitoring.

GPR frequencies for concrete

The 1.5 to 2.7 GHz frequency range is optimal for concrete inspection. GSSI's FLEX NX system (2.5 GHz), NX25 (2.5 GHz), and NX15 (1.5 GHz) antennas offer high resolution for shallow depths (30-50 cm). For thicker structures such as bridge piers, massive foundations, or old concrete over 60 cm, 800 or 900 MHz antennas provide better penetration at the cost of resolution — a trade-off inherent to GPR physics.

What these datasets let you practise

The collection goes beyond rebar detection. Several datasets cover situations that classroom teaching rarely reaches: a welded mesh overlap zone, where hyperbolas draw close and merge to the point of defeating automatic detection; a densely reinforced structure whose C-scan view stays unreadable until slice depth, gain and colour range have been adjusted; an electrical cable crossing a slab diagonally, indistinguishable from a rebar on a single profile and revealed for what it is only in 3D reconstruction.

Other datasets serve comparison: the same reference line recorded with three antennas, and dual-antenna FLEX NX acquisitions for testing cross-polarisation and channel merging. The 3D grids, with documented spacing and origin, lend themselves to plan-view reconstruction and to cover measurement once velocity has been calibrated.

Which software opens these files  ·  Select these datasets programmatically

Download raw concrete GPR data

All datasets on GPRbase are raw radargrams in .DZT format, without pre-processing or interpretation overlay. This makes them perfect for testing algorithms, training machine learning models, or teaching interpretation from first principles. Download is free, immediate, and does not require account creation — just accept the license terms and receive the files by email.