Drafted by the PIARC Technical Committee on Testing of Road Materials, this report is a direct extension of the first PIARC publication on Marginal Materials (see page 57). The first part examines the conventional tests applied to some marginal materials of the industrial by-product type and sets out the conditions to be achieved to obtain a certain international harmonization. The second part is devoted to special tests and completes, further specifies or corrects data appearing in the first publication.