Methylene Blue Value Test
The Methylene Blue Value (MBV) Test determines the presence of hazardous clay minerals in fine aggregates, particularly manufactured or crushed sand. The test, which is carried out in accordance with EN 933-9 and AASHTO T330, determines the quantity of adsorptive clays by measuring how much methylene blue dye the aggregate fines absorb. These clay particles can severely interfere with the bonding of cement paste and aggregates, resulting in decreased concrete strength and greater shrinkage. The MBV test is critical for determining aggregate purity, especially in places where natural sand is limited and manufactured alternatives are employed. Low methylene blue levels help to generate durable, stable concrete and asphalt mixes that are less prone to cracking and moisture damage.
Advantages of Methylene Blue Value Test:
- Identifies hazardous clay content in fine aggregates.
- Improves the bonding and mechanical strength of concrete.
- It prevents excessive shrinkage and cracking.
- Essential for produced or crushed sands.
- Increases the endurance and lifetime of constructions.