The most used material for formulation of plasticizers and superplasticizers for
concrete is lignosulphonate. Most of the lignosulphonate used in concrete admixtures
is consumed in the plasticizer range, but there are also lignosulphonate with
The chemical and physical difference in lignin from hardwood and softwood is
discussed in this paper. These differences are discussed with respect to performance
differences and modifications. It is demonstrated the in spite of the big differences
between hardwood and softwood lignin it is possible to produce lignosulphonate with
the same performance in concrete. The chemical and physical data of these
Lignosulphonates are very different. This is often leading to confusion with respect to
the performance of these products.
The structure of the lignin molecule is discussed and compared to that of linear
polymers. Typical linear polymer is NSF. This has impact on the understanding of the
behaviour of the polymer and the way lignosulphonate should be handled.