There are miscellaneous tests available for execution depending on the plausible root cause or critical issues. There are three types of tests which Oreads Buildingcare can conduct for hardened concrete, namely; in-situ destructive test, in-situ non-destructive test and laboratory test. Our lab and our associate labs are open to the idea of assisting academicians in their research and contractors or builders mainly in material submission, and concrete design by prescribing design mix, conducting trial mix and other scope of works. For such testing, we have our test equipment for compacting factor, vebe time, determination of air content, density et cetera. for cubes, cylinders and beams. Besides concrete, we are able to conduct flow-through tests for grout and shotcrete as well as determining aggregate properties tests. We are affiliated with local and international associates who can assist should there be a need for additional tests which are not mentioned here or not commonly available in the market.

Concrete cores

Chemical Laboratory Test

Petrographic Examination

For hardened concrete, the following are the usual tests which we are able to conduct with the assistance of lab technicians and a resident professional geologist.

Carbonation Depth Test

In order to check the chemical condition of the concrete, phenolphthalein will be sprayed on the fresh-cored sample. The depth of the carbonation is indicated by the distance and depth covered by the pink colour after applying phenolphthalein. 

Concrete Coring and Compressive Strength Test

Coring shall be in accordance with BS EN 12504-1, Testing Concrete in Structure – Cored Specimens – Taking, examining and testing in compression. In the case of any structural members having relatively intimate reinforcement nominal links, the compressive strength shall be acquired by other methods and correlated accordingly. 

Concrete Hacking Test

Concrete Hacking is a destructive test which shall be performed in order to evaluate the condition of the concrete and the reinforced steel bars in the said location. Aside from that, this will also provide the actual reinforcement bars’ size and number as well as spacing to be tallied to any indicative as-built drawing to form the steel (bending) schedule. 

Electromagnetic Covermeter Test

This test method is deployed in order to check the thickness of the concrete structure cover by determining the distance between the surface and the reinforcement bars. Aside from that, this test will ensure coring work to acquire samples will not affect the structure’s reinforcement bars. This method is specified in BS1881-204:1986, Testing Concrete – Recommendations on the use of electromagnetic covermeters.

Half-Cell Potential Test

Half-Cell Potential is a non-destructive test which shall be performed to measure the surface potential which is associated with corrosion current. This method is described in BS1881-201:1986, Testing Concrete – The Guide to the use of non-destructive methods of test for hardened concrete; Section 2.4 or may be executed in accordance to ASTM C876-80 Standard Test Method for Half-Cell Potential of Reinforced Steel in Concrete.

Rebound Hammer Test

The main method in acquiring the strength of the concrete at the site is by using the Rebound Hammer method at selected areas of the building and to be correlated to the Cored Samples. This method is described in BS EN 12504 Part 2.

Ultrasonic Pulse Velocity

This test allows measurement to be made based on the velocity of the ultrasonic pulse which can determine uniformity of the concrete, detection of cracks and determine the modulus of elasticity of the sample. The test shall be conducted based on BS1881-203:1986, Testing Concrete – Recommendations for measurement of the velocity of Ultrasonic Pulses in Concrete or  BS EN 12504 Part 4.

Chloride Content Test

Quantab Test Strip or Laboratory test would identify the level of chloride content and/or ingress into the concrete as well as a measure to check if chloride ions are passive inhibitors in the concrete structure.  Apart from that, this test shall be conducted in accordance with BS1881-124:1988.

Pull-off and Pull-Out Test

Pull-off and Pull-out tests are available in order to determine two different parameters. Pull Out test is based on BS EN 12504-3:2005 Testing concrete in structures. Determination of pull-out force standard requirement to establish the load capacity strength of fixings that have been installed or fitted into walls, slabs, soffits et cetera by measuring the force required to pull an embedded metal insert and the attached concrete fragment from a concrete mass. Pull-off on the other hand will be based on BS EN 1542:1999 Products and systems for the protection and repair of concrete structures. Test methods. Measurement of bond strength by pull-off. 

Petrographic Examination and SEM

Petrography Examination is a non-destructive test which shall be performed by utilizing concrete cores extracted at selected areas. through Scanning Electron Microscope (SEM). This method is described in BS1881-211:1986, Testing Concrete – Procedure and Terminology for the petrographic examination of hardened concrete, or/as per ASTM C856-04, Standard Practice for Petrographic Examination of Hardened Concrete.

X-ray Diffraction Analysis

This is a method used in materials science to determine the crystallographic structure of a material. XRD works by irradiating a material with incident X-rays and then measuring the intensities and scattering angles of the X-rays that leave the material. It is mainly for elements tracing which involves structural properties such as lattice parameters, strain, grain size, epitaxy, phase composition and preferred orientation. This allows the determination of components of concrete and/or geotechnical and geological materials.

Electrical Resistivity Tomography (ERT)

When typical Site Investigation works involving laboratory and field tests are not comprehensive enough to render the actual geological and geotechnical condition for deep ground mainly in dam and foundation works, Electrical Resistivity Tomography (ERT) will be the best option to complement the findings of these tests. It is a geophysical test which provides sub-structure sectional imaging where electrodes or probes are placed in a parallel order to define the properties of the sub-surface and deep strata.