BS EN 12697-11:2020 PDF Download

The BS EN 12697-11:2020 standard is focused on the determination of the affinity between aggregate and bitumen in bituminous mixtures, specifically with regards to its influence on the susceptibility of the combination to stripping. This standard provides procedures that can help designers in mixture design rather than being a type test. The affinity between aggregate and bitumen is an indication of the binder's capability to adhere to different aggregates or of various binders to adhere to a specific aggregate.

There are three methods described in the standard for measuring the affinity between aggregate and bitumen. The first method, called the rolling bottle method, involves visually evaluating the degree of bitumen coverage on mineral aggregate particles after being subjected to mechanical stirring in the presence of water. This method is simple but subjective and is suitable for routine testing except for highly abrasive aggregates.

The second method is the static test, where the affinity is assessed by visually registering the degree of bitumen coverage on mineral aggregate particles after storage in water. This method is also simple but subjective and provides less precise results; however, it is capable of handling high PSV (Polished Stone Value) aggregates.

The third method is the boiling water stripping test, which provides an objective evaluation of the affinity. It involves determining the degree of bitumen coverage on aggregate particles after immersion in boiling water under specific conditions. This test has a high precision but requires skilled operatives and the use of chemicals as a reagent. It can be used for any binder-aggregate combinations where the mineral aggregate is calcareous, silico-calcareous, or siliceous in nature.