BS EN 933 is a European Standard on tests for geometrical properties of aggregates. The main aim of the BS EN 933 series is to provide the best industry guidance to ensure construction materials contribute to the structural integrity of civil engineering works.
BS EN 933-4 is the fourth part of the BS EN 933 series that describes the reference method used for type testing and in cases of dispute, for the determination of the shape index of coarse aggregates. For other purposes, in particular, factory production control, other methods may be used provided an appropriate working relationship with the reference method has been established.
The test method specified in BS EN 933-4 is applicable to particle size fractions di/Di where Di ≤ 63 mm and di ≥ 4 mm.
BS EN 933-4 on shape index of course aggregates is useful for:
Geometrical characteristics of aggregates is an important consideration when it comes to the mix design of the roads or pavements, to avoid premature failures arising during mixing, compaction and under traffic. With the right shape index of coarse aggregates, you can ensure of proper compaction, adequate deformation resistance and workability of materials. The shape index test is used for the determination of the shape factor of aggregates. It is calculated as the mass of particles with a ratio of dimensions more than 3 expressed as a percentage of the total dry mass of particles tested.
In this regard, BS EN 933-4 provides the requirements for apparatus, reagents, test preparation and test procedure to evaluate the particle shape index of aggregates.
As a result, if you are a manufacturer of aggregates, conforming to BS EN 933-4 can demonstrate the performance and quality of your products.
Thus, compliance with BS EN 933-4 can ensure your materials and products play a positive role in the overall concrete performance for optimal durability and structural stability.
EN 933-4:2008