BS EN 933 discusses tests for geometrical properties of aggregates. BS EN 933-9 is the ninth part of the BS EN 933 multi-series and discusses the methylene blue test.
BS EN 933-9 specifies the reference method used for type testing and in cases of dispute, for the determination of the methylene blue value of the size 0/2 mm fraction in fine aggregates or all-in aggregates (MBf).
BS EN 933-9 on the determination of the methylene blue value of the size 0/2 mm fraction in fine aggregates or all-in aggregates (MBf) is useful for:
Increments of a methylene blue solution are added successively to a test portion suspended in water. The adsorption of dye solution, by potential clay minerals in the test portion, is checked after each addition of solution. This is done by carrying out a stain test on filter paper to detect the presence of free dye, which indicates that adsorption is complete.
BS EN 933-9 provides you with the reference method for the determination of the methylene blue value of the size 0/0,125 mm fraction (MBF). Other methods can be used for other purposes, such as factory production control, provided that an appropriate working relationship with the suitable reference method has been established.
BS EN 933-9 provides you with the preparation of 10 g/l methylene blue solution and specifies the procedure for the determination of the methylene blue value of kaolinite (MBk). A conformity check, adding a single quantity of dye solution equivalent to a specified limiting value and which can be used as part of a production control process, is described in BS EN 933-9.
BS EN 933-9:2022 supersedes BS EN 933‑9:2009+A1:2013, which is withdrawn. BS EN 933-9:2022 includes some technical changes with respect to BS EN 933‑9:2009+A1:2013. These include:
EN 933-9