Identify and mark sample collection points on the concrete structure to ensure representative analysis. 

Extract concrete samples using a core drill, minimizing structural damage and sample contamination. 

To minimize carbonation effects, it is recommended that samples should be adequately labelled and sealed immediately after coring by wrapping and storing in sealed polyethylene bags.  

Taking core samples to laboratory, break the extracted samples into smaller pieces, then grind them to a fine powder to increase reactive surface area. 

Coring equipment and a hammer for sample collection/preparation. 

Mortar and pestle or ball mill to powder cores for chemical analysis. 

Precisely quantifies Ca(OH)2 (Portlandite) levels, providing insights into concrete's resistance to environmental deterioration and structural integrity. 

Gives empirical values for the level of carbonation encountered at various places in the same structure or across different facilities allowing visual representation of at risk areas and intelligent mitigation / repair strategies. 

TGA testing utilizes a rigorous methodology, offering highly precise measurements of weight changes in concrete samples, enabling accurate quantification of components. 

A small amount of materials is required for the test limiting the cost and time consumption of repair procedures and expanding the areas which can be sampled. 

TGA instruments are extremely costly to purchase, maintain and operate or rent the use of.  

Interpretation of TGA results requires a high degree of expertise in materials science and chemistry. For instance, distinguishing between weight loss due to portlandite decomposition and other overlapping thermal events, such as the dehydration of ettringite or the decomposition of carbonates, demands specialized knowledge. 

The accuracy of TGA results can be highly sensitive to the sample's preparation. Achieving a homogeneous, finely ground powder that accurately represents the bulk material can be challenging, particularly if the sample contains large aggregates or reinforcing materials. 

While TGA provides valuable quantitative data on component weight changes, it offers limited insights into the concrete's microstructural properties, such as pore size distribution or crack propagation.  

Some components within concrete may undergo irreversible changes or decompose at the high temperatures used in TGA, potentially altering the material's original chemical structure. This makes it challenging to correlate the findings directly to the material's behaviour in normal environmental conditions. 

A single TGA run, including sample preparation, heating, cooling, and analysis, can be time-consuming, limiting its practicality for rapid, testing in construction settings where quick decisions might be necessary.