Types of Faults Identified Through Concrete GPR Screening

Concrete is an integral structural material and there's need to make sure it doesn't feature any faults or defects. Concrete GPR screening involves the use of ground penetrating radar devices to identify any spaces, referred to as voids, inside a concrete beam or slab. GPR employs the use of a high frequency radio pulse which is sent into the concrete material. The reflected signals are then sent back to the receiver and saved on digital media. A computer calculates the time taken for the signal to travel across the concrete surface which reveals its depth as well as location. By using GPR in this manner, concrete contractors can quickly, safely and affordably inspect large sections of concrete throughout the construction stage. Any defects can then be rectified as early as possible. Here are the faults in concrete that are identified through GPR screening.


Declamation refers to a scenario where two segments of concrete attached together fail to bond well resulting in two or more sections. An interruption during the concrete pour phase is often the cause of this problem. Concrete contractors cannot identify this type of defect with their naked eye. However, with radar screening, they can detect the existence and degree of declamation.

Honey combing

This refers to the stoniness or coarseness in the concrete. It reveals a section of weakened concrete which will upset the durability and robustness of the concrete. Common causes of honeycombing include inadequate fine material in the concrete aggregate mixture, poor mixing of the concrete aggregate, and sometimes leakage of the mortar constituent of the concrete surrounding the joints or the formwork. The magnitude of honeycombing is concealed under the surface; however, slab screening using concrete GPR is able to highlight the scale of the problem.


Concrete is subject to a porous effect whenever it's screened prior to being afforded adequate time to bleed. When the water within the concrete evaporates, it creates little spaces where the water previously had been. These voids can be seen through GPR screening.


Whenever the reinforcing bars in the concrete slab shift for whatever reason during the setting phase, the concrete and the bars are likely to de-bond or fail to bond at all. One of the probable reasons behind the shifting of bars during the setting phase is contractors stepping on the steel mesh in the course of the pour as they operate the vibrators. A significant shift of the reinforcing bars results in voids being formed nearby the rebar. This is referred to as de-bonding. Concrete contractors using concrete radar screening devices can examine the affected section and know the exact location and magnitude of de-bonding.