BS EN 12697-8:2018

What is BS EN 12697-8- Void characteristics of bituminous mixtures about?    

BS EN 12697 is a European Standard that discusses bituminous mixtures and related test methods. The main objective of the BS EN 12697 series is to ensure that the quality and performance of bituminous mixtures contributes to the structural integrity of your civil engineering works. 

BS EN 12697- 8 is the 8th part of the series that describes a procedure for calculating volumetric characteristics of a compacted bituminous specimen: the air voids content (Va), the voids content in the mineral aggregate filled with a binder (VFB) and the voids content in the mineral aggregate filled with binder and additives (VFBad) for the case of mixtures containing additives in their composition. 

These volumetric characteristics can be used as mixed design criteria or as parameters for evaluating the mixture after placing and compacting on the road. 

Who is BS EN 12697-8- Void characteristics of bituminous mixtures for?   

BS EN 12697-8 on the determination of void characteristics is relevant to:   

• Manufacturers and suppliers of bituminous mixtures   
• Suppliers of construction materials   
• Construction industry 
• Contractors and civil engineers  
• Road maintenance authorities   

Why should you use BS EN 12697-8- Void characteristics of bituminous mixtures?    

Air void is defined as the pocket of air between the bitumen-coated aggregate particles (including any existing additives) in a compacted bituminous specimen. This parameter plays an important role in determining the compacting behaviour and overall performance of bitumen.  

In BS EN 12697-8, the air voids content of a bituminous specimen is calculated using the maximum density of the mixture and the bulk density of the specimen. For mixtures with water in their composition (e.g. mixtures produced with bituminous emulsion or foamed bitumen), the bulk density of the specimen refers to its dry bulk density. 

The method described under BS EN 12697-8 is suitable for specimens that are laboratory compacted or specimens cut from the pavement after placement and compacting or from laboratory compacted slabs, either by coring or sawing. 

Overall, compliance with these test methods can help demonstrate the durability and performance of bituminous mixtures and whether or not they are fit for purpose. The test results provide indications on the quality and lifetime of the pavement or road subject to traffic loads. If you wish to maintain stability during compaction process, avoid ruts and grooves and prevent deformities, BS EN 12697-8 can be your guide.  

What’s changed since the last update?   

BS EN 12697-8:2018 supersedes BS EN 12697‑8:2003, which is withdrawn. The following is a list of significant technical changes since the previous edition: 

• The series title no longer makes the method exclusively for hot mix asphalt 
• Change of indices in symbols for void content, binder density and binder content 
• Clarification that specimens cut from the pavement or from laboratory compacted slabs can be by either coring or sawing 
• New term and definition of VMAad  and VFBad inserted 
• [5.1] The principle for mixtures without additives is now described in the new sub-clause [5.1.1]. New sub-clause added for mixtures with additives [5.1.2] 
• [5.2] The calculation for mixtures without additives is now described in the new sub-clause [5.2.1]. New sub-clause added for calculation of mixtures with additives [5.2.2] 
• [5.4] dimension of a specimen to the nearest 0,1 mm (if measured) added to results