Use coring to remove sample from a concrete structure or specially cast specimens, ensuring they meet size and shape requirements as per BS EN 12390-13:2021. 

Apply a basic stress of 0.5 N/mm² to the specimen. 

Incrementally increase the stress to one-third of the specimen's previously measured compressive strength from 2:1 cores, preferably 150x300mm. 

At each loading, the strain experienced by the specimen is recorded by the test device. 

Divide the stress difference (basic to upper stress) by the corresponding strain difference. 

Analyse the recorded strains and calculated modulus for insights into the concrete's structural health. 

Report your results including the specimen's identification, test date, age, shape, dimensions, stress-strain data, and the calculated modulus of elasticity. 

Provides most accurate predication of structural behaviour by precisely assessing concrete's elasticity and how the structure will respond to stress and load, crucial for safety and design optimization. 

Offers deep insight into concrete quality and composition, essential for assessing durability and the potential for future issues. 

Helps detect and quantify hidden damages or weaknesses in concrete, critical for maintenance planning and avoiding catastrophic failures. 

Core extraction can compromise structural integrity, requiring careful consideration of locations and subsequent repairs to avoid weakening the structure. 

Requires specialized laboratories, equipment and expertise, making it quite expensive and time-consuming. 

Results only reflect the condition of the specific locations sampled, which might not represent the entire structure's state, necessitating strategic sampling to mitigate this issue. 

The extraction process leaves voids that need filling, which can be difficult to match with the original concrete, impacting aesthetics and potentially strength. 

In structures with historical or architectural significance, taking cores could compromise structural integrity, aesthetic appeal or historical authenticity.  

Structures with embedded systems electrical, plumbing, or mechanical systems, may also be unsuitable for coring without risking damage to these systems. 

The process of coring and testing can pose safety risks, especially in deteriorated or hazardous structures. Environmental and safety precautions are necessary to manage hazards associated with coring, including dust control, asbestos protection and structural stability during and after core extraction. 

Testing provides information only about the specific locations from which cores are taken, potentially missing variations in materials or conditions across the structure.  

Holes left from coring must be repaired ensuring that these areas are as strong and durable as the rest of the structure. 

The process of core extraction, testing, and subsequent repairs can be costly and time consuming. In some cases, the financial implications may outweigh the benefits, especially for large-scale or complex structures where extensive sampling is necessary. 

The accuracy of the test results heavily relies on the expertise of the personnel conducting the tests. The need for specialized equipment and knowledge can limit the availability of testing, especially in regions or contexts where such resources are scarce. 

The condition of the concrete, including moisture content and temperature, can significantly affect test results. Testing specimens that are not representative of the structure's typical state can lead to inaccurate assessments. 

The act of coring itself can compromise the structural integrity of the concrete, especially in critical or already weakened areas. This is a significant concern in load-bearing elements or in structures where redundancy and load paths are not well defined.