Why Concrete Testing?
Projects and budgets can be at risk if concrete is not tested to the relevant BS or BS EN Standards. Simtec endeavours to keep a project always moving forward towards successful completion. Our extensive testing capacity provides clients with the peace of mind and assurance they need to progress their projects.
Benefits of Concrete Testing
Concrete testing offers a wide range of benefits to clients within the construction industry. Results from laboratory concrete testing enable clients to:
- Understand the reliability and strength of hardened concrete
- Ensure the concrete can withstand the designed level of compression
- Reduce project risk in terms of both time and cost
Concrete testing ensures the optimisation of concrete mix design, including for specialist applications. It also offers a highly accurate determination of strength in various temperatures and other relevant conditions. This is especially important for informing decision-making processes for project progression.
Hardened Concrete Compressive Strength Testing
To verify the strength of a freshly mixed concrete, cube samples are taken in either 100mm or 150mm cube moulds. Before their compressive strength can be tested, the cubes must be cured in a water bath for 28 days. They are then placed into a compression machine, where they are subjected to increasing load until failure.
The resulting maximum load will be divided by the cross-sectional area of the sample to calculate its compressive strength. The compressive strength can then be compared to the design strength of the concrete mix. This is critical for determining if the mix can reliably withstand the weight and pressures of its intended use.
Petrographic Examination
Petrographic examination is the microscopic examination of thinly sliced sections of concrete cores. This method is essential for identifying the mineralogy and constituents of a concrete mix, alongside uncovering any degradation present. This includes a detailed petrographic report to follow.
Petrographic samples are usually prepared from core or lump samples. Once the concrete has hardened, it is cut, ground, and polished for examination. The surface can then be examined with a microscope to analyse the presence of the various minerals and chemicals.
Reference
The relevant UKAS accredited laboratory tests for fresh and hardened concrete, and the corresponding standard numbers are:
| Test | Standard Number |
|---|---|
Sampling fresh concrete on site - composite sample - spot sample |
BS EN 12350-1:2019 |
Slump |
BS EN 12350-2:2019 |
Making and curing specimens for strength tests |
BS EN 12390-2:2019 |
Flow table test |
BS EN 12350-5:2019 |
Air content - pressure gauge method |
BS EN 12350-7:2019 |
| Test | Standard Number |
|---|---|
Taking cores |
BS EN 12504-1:2019 |
Compressive strength of cubes - including curing |
BS EN 12390-3:2019, BS EN 12390-1:2021, BS EN 12390-2:2019 |
Density |
BS EN 12390-7:2019+AC 2020 |
Cored specimens - examining and testing in compression |
BS EN 12504-1:2019 |
Concrete Testing Services
- Compressive Strength
- Tensile Strength
- Density
- Water Absorption
- Cement Content
- Sulphate / Chloride Content
- HAC Content / Presence
- Carbonation Depth
- Mix Design
- Laboratory Trial Mix
- Cube, Cylinder, and Beam Manufacture
- Air Content
Frequently Asked Questions
Why is the compressive strength test important in the construction industry?
The compressive strength test for concrete is one of the most important concrete testing methods within the construction industry. Understanding the characteristics and behaviour of a concrete mix can help make important design decisions to ensure buildings and infrastructure are structurally sound.
What is the purpose of the petrographic analysis of concrete?
There are multiple benefits of petrographic examinations. By identifying the mineralogical and chemical makeup of the concrete mix, experts can determine the cause of low compressive strength, surface scaling, and concrete degradation. This is an important part of deciding to reuse or replace a concrete mix.
What is the sample size for petrographic analysis?
For a petrographic examination, core sample sizes can vary depending on the laboratory. Generally, concrete testing cores are from 2 to 4 inches in diameter.