Pull-Out and Pull-Off Tests on Concrete: Extraction Testing

We have previously discussed the phenomenon of concrete degradation and the need for continuous monitoring of its performance to assess its safety condition and intervene in case of anomalies or defects. We have also presented two types of non-destructive testing in a previous article: ultrasonic tomography and ground-penetrating radar. In this article, we will delve into another type of test, the pull out test and pull off test, and introduce two Novatest instruments for comprehensive and reliable investigations.

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Pull Out Tests: What Are They and How Are They Conducted?

Pull out tests are used to evaluate the health of concrete structures by measuring their resistance, which is defined as the force required to extract a metal anchor embedded in the material (UNI EN 12504-3:2005).
If the anchors were previously inserted into fresh concrete, the test does not require drilling a hole on the surface of the examined structure. By using a hydraulic jack, the anchor is tensioned until it is extracted due to the applied compression force.

If the anchor was not previously inserted, a post-installed anchor is used. The anchor is inserted into an internally countersunk hole, and it is driven in so that the internal radial body adheres to the walls. The value of the maximum force required for extraction determines the experimental correlation curves to establish the average concrete strength (Rmc).

Pull Out Tests: Kit Pull Out STD

The Novatest Kit Pull Out STD is a hydraulic system consisting of a manually operated pressurization unit equipped with a pressure gauge that activates the hydraulic jack connected to the anchor embedded in the concrete.

Would you like to learn more about the technical features and benefits of the Kit Pull Out STD? Request a free consultation now!

Pull Off Tests: What Are They and How Are They Conducted?

Pull off tests measure the tensile strength of renders, resins, mortars, paints, and other materials using a hydraulic system with a jack connected to a pressure gauge that records the rupture value. This test is suitable for assessing the adhesion quality of Fiber Reinforced Polymer (FRP) to the substrate, following the CNR-DT 200/2004 standard.

SA circular incision is made on the surface to isolate the test area, and a metal disk is bonded to it. A perpendicular tensile force is applied to the disk until a rupture occurs between the coating material and the substrate.

Pull Off Tests: Kit Pull Off 500

The Novatest Kit Pull Off 500 is a hydraulic system for pull-off adhesion tests, allowing the measurement of tensile strength.

Would you like to learn more about the technical features and benefits of the Kit Pull Off 500? Request a free consultation now!

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