Knowing the Difference: Concrete Scanning Rebar/Conduits/Post Tension Cables

Why Concrete Scanning is Important:

There are so many reasons concrete should be scanned prior to any penetration or cutting of the surface.  A relatively quick scan of the concrete prior to cutting can save countless dollars and headaches, and in many cases, even a workers life.  Before we even start, we examine the site because the slab thickness, soil and conditions beneath the slab as well the steel content can make conditions more difficult. We also locate sewer and sanitary lines under the concrete floor for your future tie in. 

The Concrete Scan Process:

Our Concrete Scanning & Imaging service utilizes ground penetrating radar (GPR) to detect conflicts such as conduits, reinforcement, post tension cables and more in concrete floors, slabs, walls, columns and other surfaces. Concrete imaging utilizes a high frequency radio wave emitted from the radar unit to detect the presence of conflicts. Although this high frequency provides a much higher resolution image compared to the traditional, larger, outdoor ground penetrating radar, it does not provide as much penetration into the scanning surface. We typically can detect objects up to a depth of 20 inches using a GPR concrete scanner. Trinity Subsurface also employs electromagnetic technologies to detect utilities that may be outside of the GPR limitations.  Using multiple tools and techniques ensures the area has been scanned as thoroughly as possible.

Finding Rebar:

When a construction project is taking place there are times that drilling or cutting needs to be done through the concrete. The rebar, short for reinforcement bar, is used in concrete construction to strengthen the structure. Rebar can be found scanning a floor, wall and column. Reinforcement steel is typically present and marked over the surface to ensure drilling does not compromise the structural integrity of the concrete. 

Finding Conduits: 

Using concrete scanning is very important when trying to locate conduits and process lines sometimes buried in concrete.. A conduit or utility can be found in the concrete slab, below the slab or within screed layers. It is essential that electrical conduits, communication lines, and process piping are detected during a scan to prevent any outages, injuries, and costly damages. You can also find plastic and metallic conduits in the floor.

Finding Post Tension Cables:

You typically find post tension cables to support walls and also top and or bottom on concrete. The cables are usually found in apartment buildings, parking garages, bridges, and office buildings. There are two main types of post tensioning which are bonded and unbonded. The unbonded post tension cable has no bond between the prestressing steel and the concrete surrounding it anywhere except at the anchorages. You find this within the beams and slabs. Cutting a post tension cable is an extremely dangerous and costly mistake!

Finding Voids:

Concrete Scanning can also be utilized to  look for voids and air air gaps that are found in slabs on grade and subgrade. The voids would be found under concrete or asphalt surfaces. A void will typically occur when there is erosion, compaction or pipe bursting. This can stay undetected if concrete scanning doesn’t take place. If the problem goes undetected, serious deterioration of the structural integrity or building collapse could occur.  A void detection scan is also a good idea to partner with our Leak Locating Services. .

In addition to a superior utility mark out using crayon, chalk, paint, or other suitable marking device for the work area, you will receive a field report. At Trinity we take pride in our services and all concrete scanning and imaging will come with a deliverable which is customized to what you need.

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