Unreinforced Masonry Testing

Unreinforced masonry (URM) testing consists of non-destructive and intrusive investigations on brickwork and stonework, which are common and often used in heritage building systems throughout New Zealand.

1. What is Unreinforced Masonry Testing?

Unreinforced masonry (URM) testing consists of non-destructive and intrusive investigations on brickwork and stonework, which are common and often used in heritage building systems throughout New Zealand. Tests can be done on the individual masonry units, the bonding mortar, or the combination of these.

The non-destructive tests include:

  • Scanning. Utilising GPR, magnetic induction, UT, or a combination of these techniques, scanning can be done on most structural masonry types. The following information can often be collected through scanning
    • Identifying unfilled cells within concrete block masonry structures
    • The presence of voids or delamination
    • The presence of metal ties
  • Camera inspection. Once the presence of reinforcement or ties have been confirmed, our inspection camera can be utilised to check the condition of these elements; whether they are well-maintained or corroded. This service may be done in conjunction with a localised break-out (intrusive testing)

The intrusive tests include:

  • Mortar joint shear strength test
  • Compressive strength test
    • On an extracted prism of URM
    • On individual masonry units, i.e. bricks or mortar cubes
    • Test to Standard NZS_3112:Part_2:1986
  • Anchor test. There are two categories of tests that can be performed on anchors imbedded in URM.
    • Proof test, to check the quality of installation.
    • Ultimate test, to check the maximum load that can be sustained before failure
    • The above tests can be applied in shear or tensile (pull-out) testing.
  • Scratch test for mortar strength estimation in-situ.

2. When would you use Unreinforced Masonry Testing?

URM testing will be very useful when structural engineering consultancies are required to perform retrofitting design on URM structures. URM structures have been shown to perform poorly during earthquakes and it is now mandatory to strengthen these structures in the most seismically active regions in New Zealand, such as Wellington and the Canterbury area. Our service can provide the information required by the design engineers to perform their calculations for the retrofitting purpose.

3. What are the Benefits of Unreinforced Masonry Testing?

Just like any other construction materials, it is important to know the actual properties of the masonry units constituting the concerned structures before any reliable retrofitting design can be performed. However, masonry structures, especially those composed of clay bricks or stones, are so inhomogeneous that their strength properties highly depend on a range of factors, primarily workmanship. It is not advisable to perform the retrofitting design using the value of these strength parameters obtained from literature. Through our service, the representative value of these parameters can be provided. Beside the information obtained through scanning, the following strength parameters required for retrofitting design can be obtained through the services above

  • The shear strength of the mortar bed joint under different axial load intensities
  • Single unit as well as prism masonry compressive strength to see the slenderness effect
  • Anchor pull-out or shear capacity of the masonry unit through anchor test. Anchors are the means of attaching structural steel members to masonry structures required for strengthening.

When the representative values of these parameters are known, design engineers can perform their retrofitting design with higher confidence.

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Kurtis and his team showed highly skilled reading of scan results. These allowed them to be the only ones who successfully located the defects (random voids) in Polystyrene blocks filled with concrete and lined with Gib in a prepared area...

Maynard Marks

Engaging CSI to conduct the Pile Integrity Testing on the large 1.8m diameter piles was a wise choice. Their technicians were knowledgeable, approachable, punctual, health and safety conscious and flexible when we encountered late changes to the works programme. Results...

Fulton Hogan

As requested, the workers from CSI ltd contacted this office on arrival at the site and invited me (Kevin J Heays) to site visit and get an understanding of the intended works. I was impressed with the workers knowledge of...

Kevin Heays (ECANZ)

The CSI team were great and they did a good job for us. They were employed to complete QA on a Wellington Apartment Development using Pile Integrity Testing. We would recommend CSI to others in the future.

Richardson Drilling

CSI did a good job for us at an Auckland Apartment building; saving our team from drilling through services which would have caused considerable delays. We would recommend CSI to others for scanning

Allendale Electrical

CSI provided a great service. We could not advise them on areas of improvement as their service was highly professional.

Wilson Building

We found CSI via their website and were grateful that we had. Their service was highly professional.

Artisan Developments Ltd

CSI have completed several jobs for us. They are highly skilled operators.

Tracer Construction

CSI was recommended by a health board, and they did a great job for Q Interiors. We are already looking at employing them for future work.

Q Interiors

The service and follow-up of CSI Ltd was excellent. We would definitely use them again.

Grayburn Property Service

CSI Ltd did a great job for us. When we were asked what improvements could be made, we could think of no gaps in their professional service.

Trademark Building Services

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Stanley Construction

We were recommended CSI by an Engineer and he was absolutely correct; their GM particularly communicated well and was highly professional.

MSC Consulting Group

CSI has completed some exciting projects with Novare Design “I am very impressed at the responsiveness, relevance and accuracy of the testing and data supplied to Novare for some recent strengthening projects. We have worked with CSI on several projects...

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Darren, Ali and the team at CSI have been a great help at the Oaks Shores refurbishment project. CSI was willing to work through the difficulties of travel under various Covid-19 levels, ensuring they could be of assistance in Queenstown...

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