What is BS EN 13286-1 about?  
BS EN 13286-1 is the first part of the multi-series of documents that is applicable to unbound and hydraulically bound mixtures.
BS EN 13286-1 specifies a number of test methods for the determination of the relationship between the water content and the density of unbound and hydraulically bound mixtures under specified test conditions. The test results provide an estimate of the mixture density that can be achieved and provides a reference parameter for assessing the density of the compacted layer of the mixture.
The test results are used as a basis for specifying requirements for hydraulically bound and unbound mixtures.
The test result also allows a conclusion to be drawn as to the water content at which a mixture can be satisfactorily compacted in order to achieve a given density.
Who is BS EN 13286-1 for?
BS EN 13286-1 on unbound and hydraulically bound mixtures is applicable to: 
- Manufacturers and suppliers of unbound and hydraulically bound mixtures
- Suppliers of binders such as cement, fly-ash needed to make hydraulically bound mixtures
- Equipment suppliers
- Civil engineers
- Contractors
- Highway and road transport authorities
Why should you use BS EN 13286-1?  
A hydraulically bound mixture is a mixture of aggregate, water and hydraulic binder and is one of the most commonly used materials in pavement sub-base layers where cement-treated bases or cement-bound materials have traditionally been used. For the optimum functioning of hydraulically bound mixtures, water content is a important factor as it decides on the hardness of the material that gains strength over time by creating interlocking bonds.
The test described under BS EN 13286-1 provides an estimate of the mixture density that can be attained as well as a reference value for assessing the density of the compacted layer of a mixture. The findings of the tests are utilised to set requirements for both hydraulically bound and unbound mixtures.
BS EN 13286-1 provides an estimate of the mixture density that can be achieved on construction sites and provides a reference parameter for assessing the density of the compacted layer of the mixture.
These provisions given in BS EN 13286-1 help you to ensure quality and performance by reducing the cost of material production by eliminating quarrying, crushing, and screening operations. For repaving projects, it reduces handling and transportation costs too. Moreover, quicker compaction times sometimes associated with hydraulically bound mixtures, can help reduce congestion for road users. 
What’s changed since the last update?
BS EN 13286-1:2021 supersedes BS EN 13286-1:2003, which is withdrawn. BS EN 13286-1:2021 has been editorially revised.
 Apart from editorial changes, the following change has been made in comparison with EN 13286-1:2003:
- In Table 1, a change to the particle size range for the vibrating hammer test in reflection of the change in EN 13286-4
