Monday, November 5, 2012

The Advantages of Using Ground Penetrating Radar to Establish Concrete Slab Thickness


Ground penetrating radar is actually a valuable tool for figuring out concrete slab thickness very easily along with accurately. Figuring out slab thickness is vital in seeing how concrete pavements will perform during their service life. Remember that actually a reduction in the thickness of the slab simply by as little as 1 inch may halve its service life. Computing the thickness of concrete slabs is additionally important in figuring out if contractors have complied with the job specifications whenever constructing concrete pavements.


GPR is really technology that's currently being widely used in many states as part of their pavement evaluation systems, including North Carolina, Texas, Florida, Michigan and Louisiana, as well as in many European countries such as the UK, Finland and Denmark, with much success. The radar sends quick pulses of radio waves straight into the concrete and then makes use of the arrival time and strength of the returning echoes to compute thickness as well as properties like moisture content. However, GPR might not end up being in a position to make accurate measurements in the event that there is insufficient contrast in between the concrete along with the underlying base.

What happen to be the advantages of using GPR in measuring concrete slab thickness?

1. Thickness data coming from the GPR can be right away imported into pavement management systems so that they can determine the rest of the life of the concrete pavement and figure out the correct maintenance along with repair actions. Radar readings may end up being converted into visual representation for simple interpretation or as ASCI file output.

2. Measurements can end up being carried out by GPR equipped cars along with nominal disruption to regular traffic because there is no longer any need to shut down lanes while measurements are being taken. Cars may cover as much as 200 miles each day of pavement at regular highway speeds. And automated data collecting significantly cuts down on the time required to complete the survey.

3. The price of GPR is much more affordable compared with traditional methods of determining slab thickness including taking core samples. Concerned agencies have the option of purchasing their own equipment along with training personnel to man it or contracting services from providers, depending on the budget available to them for these types of functions.

4. Highway personnel tend to be entirely safe whenever taking measurements because they are no longer exposed to dangerous situations including high-speed traffic, inclement weather as well as air pollution.

5. GPR enjoys a high range of accuracy within its measurements of concrete slab thickness. Depending on the kind of layer being measured, you can enjoy accuracy and reliability within range of 3 % to 5 % (for completely new asphalt). But actually measuring thick granular base may provide results precise to inside range of 8 % to 15 %.


Sunday, November 4, 2012

Precisely How To Decide Upon Ground Penetrating Radar Services


Ground penetrating radar services tend to be versatile enough to be used for a variety of applications, which range from discovering concealed utility pipes as well as conduits in concrete slabs to locating archaeological treasures within excavation sites. This specific technology fundamentally draws a picture of what's buried underground by sending pulses of radio waves into the target area. When the waves come across a blockage, they produce echoes which may be graphically shown on the GPR unit's screen.



There usually are 3 fundamental kinds of data which can be provided by a ground penetrating radar device. The most basic is actually 2D data, which is the raw data that's produced by the GPR and shows up as a number of roughly-drawn lines on the screen. 3D data is actually made by merging multiple 2D readings to develop 3D picture. Lastly, point data is created when the GPR is coupled with a global positioning system unit. The coordinates created by the GPS are usually combined with the GPR data to create as-built drawings upon CAD or perhaps GIS software.

Ground penetrating radar services generally take about three approaches to a GPR survey. The first is to basically examine the site for clues to the desired targets, and then make use of this as a starting place for a far more detailed search. The GPR is actually moved across the suspect region right up until the target is located, and then marked upon the ground or perhaps its coordinates logged making use of a GPS. Using mark out approach, an even more methodical search is actually undertaken by dividing the search region straight into a grid and then relocating the GPR across every individual square within orderly search pattern. Finally, there is actually the generation of a 3D map of the search area, which may be produced using the information generated from earlier searches using the first two approaches.

When hiring ground penetrating radar services there are three primary considerations to keep in mind:

1. What kind of technology are they using? You will wish to make use of service that uses the most current GPR devices accessible to ensure that you get the results you'll need.

2. Do they have a highly trained staff? While it is an easy task to run the GPR unit on its own, you will still wish to have an experienced technician on hand to interpret the readings to make sure that practically nothing is missed.

3. How long have they been operating? You will wish to retain the services of a service that is well-established in your town to make sure that they're reliable and may supply you with the services that you need.


Monday, October 29, 2012

The Many Uses Of Ground Penetrating Radar



Ground penetrating radar just recently promised to become critical in the solving of one of America's most enduring unresolved secrets: the ultimate fate of former Teamster's President Jimmy Hoffa. After a tipster advised Roseville, Michigan law enforcement that he spotted a body being entombed under the driveway in July 1975, just a day following Hoffa vanished, police officers used GPR and discovered an "anomaly" below the place. The fact is, dirt specimens used for testing showed that no human remains had been entombed there, and the solution to Hoffa's disappearance is still to be found.

For many members, however, GPR is often used for a lot more boring reasons. As an example, GPR technology can see whether there are below the ground water mains or maybe utility lines in construction sites which might be damaged during excavation and therefore that might trigger job downtime plus costly delays because of repairs to the damage caused. In addition, it will detect the existence of obstructions like reinforcing steel and voids, which could contribute to worker injury. Also the price of making use of the technology is ultimately more cost-effective as compared to the cost of getting to cover the costs associated with accidents and structural damage.

Ground penetrating radar makes use of high frequency radio signals sent in to the soil to be able to identify underground things. Their presence is indicated when the signal returns to the receiver as echoes and then the outcomes are displayed on the GPR display screen.

The depth and location of the items are depicted by the length of time it takes the echo to travel to and from it. The data are at that point translated by the technician whether the object is the root or subsurface infrastructure. Software can also be used to turn the raw data into three-D maps which allow the features to become more readily interpreted as they are shown in a more visual form.


Several types of ground penetrating radar models could be used dependent on the item being detected along with the surface type on which it is being utilised. Let's say, for anyone who is finding rebar in cement, the 1,000 MHz high-frequency GPR can be selected as that will provide high res for up to Twenty-four inches deep. On the other hand, whenever you require much deeper penetration, just like if the radar is going to be applied in ground soil, reduced frequencies from 12.5 MHz up to Five-hundred MHz are generally selected which could supply depth range that can go from a few inches up to thousands of feet.

Sunday, October 28, 2012

What Are The Distinctions Between Concrete X-ray and GPR?

Concrete X-ray is in reality a misleading expression since many workmen use it to mean ground penetrating radar. Adding to the confusion is that, although concrete radiography is progressively being superseded with GPR, older technology is consistently utilised. Cement radiography involves taking x-ray images of the layers of concrete to find out where post-tension cables, rebar as well as conduits are placed within it. The X-ray machine can go through approximately thirty inches inside of the slab and sometimes even deeper depending on its composition, and take really thorough images which are simpler to read compared with GPR records.


Are there any other differences between concrete x-ray and GPR?

1. Cement radiography has to be processed off-site. The results of the scan are put onto x-ray film, that still has to get developed before the outcome can be viewed. With GPR, the end results instantly appear on the unit's digital screen. However, a lot of radiography providers have mobile darkrooms that enable the film to be|developed on location, giving you the outcomes in minutes.

2. Cement radiography uses each side of the slab for scanning, with one end containing the film and the other the reflector plate. Therefore, there are limitations with the thickness of the slab being scanned. If you have iridium-based radiography machines, you are able to scan a slab as much as twelve inches, whereas by having cobalt-based radiography it is easy to read slab with a maximum thickness of 36 inches.

3. Concrete radiography demands the operator to wear safety gear such as a lead apron to keep them protected, and having an eighty ft space around the slab to make sure that viewers will not be come in contact with the radiation out of the x-ray unit.

4. Concrete radiography is actually more expensive than GPR because of the higher cost of the equipment involved as well as the wages of the x-ray specialist handling it. Alternatively, the GPR operator could be taught to manage the machine just in 1 day, although you would still require an experienced technician in order to interpret the information.

5. Concrete radiography can't get data on large building sites. If you would like gather info from larger slabs, you simply must continually set up the concrete x-ray device at several areas where you want to gather data. By contrast, GPR is a tool which can take measurements of large areas merely by being set up once.


Wednesday, October 24, 2012


Concrete scanning is an essential solutions for contractors excavating a construction site, because it helps them find and get away from trouble spots that causes job slowdowns or maybe shutdowns. Generally known as ground penetrating radar (GPR), this kind of engineering works on the radar that will sends out small bursts of radio wave pulses to see if you can find any specific obstructions in the underground section. The appearance of a blockage is indicated whenever an echo is seen and the depth from which it's situated can be discovered by how lengthy echo takes to go back along with the intensity of the signal.

Concrete scanning is usually used for the subsequent features:
  1. Diagnosing leakages in water lines. It can be hard to look for leaking in tubes running below concrete slabs without having to excavate the slab. With GPR, you can easily know if there is drip and where it is to ensure plumbing technicians will start digging in that area. Unseen and then unrepaired leakages can result in expensive water bills in addition to severe property damage
  2. Locating utility pipes. One of the primary hazards in building sites is that you'll by mistake drill down in to underground utility lines, which causes destruction that can induce thousands of dollars to refurbish. GPR permits you to discover places where there exist electricity lines to enable them to be stayed clear of.
  3. Determining soil composition. GPR can easily review the make up of the soil where the structure will be constructed, to make sure structural integrity and prevent future complications, such as the foundation abruptly sinking because of the ground is too soft to take the weight.

However, GPR innovation has its boundaries, the most serious in which is that this can not work as well in a few kinds of land surface, like wet clay that ground that has been greatly contaminated by salt.

Before the site undergoes concrete scanning, there are some things you must do to prepare it to allow you to get essentially the most precise effects from GPR.

  1. Get rid of all muddle from your area to get examined, because this can hinder the radar and affect the end results.
  2. Determine substitute locations to be examined if the initial location turns out to be not fit.
  3. Make sure the soil is dried up before having it looked at, because waters mirrors radar signal and thus, the radar will give undependable outcomes.
  4. If you are using the radar in order to find underground conduits, switch on the circuits because high voltage conduits are simpler to locate when compared with lower voltage ones.



Contact CSI Concrete Scanning and Investigations before you drill, cut or core concrete. For work place safety and to keep your project from costly down time, concrete scanning is essential.