Condition Assessments with Impact Echo – Concrete Beam

Dec 8

In a recent structural assessment project in Houston, Texas, OmniVueNDT employed advanced non-destructive testing (NDT) methodologies to evaluate the integrity of a concrete grade beam within a building. The primary objective was to identify and assess potential flaws or voids that might compromise the structural support of the beam. Unseen defects and flaws in concrete structures always mean bad news even in the first phase of the construction and often result in structural concern.

Upon the removal of formwork after a concrete pour, an observable and significant damage on the top left corner of the grade beam prompted the need for a thorough assessment. The chosen NDT technique for this project was the Impact Echo (IE) method, utilizing the PROCEQ Pundit PI8000 instrument (refer to Image #2).

To enhance the accuracy of the assessment, a high-frequency Ground Penetrating Radar (GPR) scanner, specifically the STRUCTURESCAN Mini from GSSI, was employed before the IE test. This step aimed to create a detailed layout of the rebar reinforcement within the concrete beam. The rebar layout information was then used to establish the grid for the subsequent Impact Echo testing.

The Impact Echo tests were conducted on the concrete surface, following the predetermined rebar layout. To facilitate data interpretation, a 2.5D numeric interpretation was generated (refer to Image #3). Post-processing of the data resulted in an actual contour map, represented as a heat map (refer to Image #4). This contour map was seamlessly integrated with a LiDAR imaging 3D model to enhance the accuracy and visualization of the structural condition.

The utilization of advanced NDT techniques such as Impact Echo, coupled with high-frequency GPR and LiDAR imaging, provided a comprehensive understanding of the structural integrity of the grade beam. This methodology enables civil and structural engineers to make informed decisions regarding potential repairs or reinforcements, ensuring the long-term stability and safety of the building structure.