Renewable energy sources are developed worldwide because of high oil prices and to limit greenhouse gas emissions. In this context some groups have focused their work on vegetable oils and particularly on microalgae. The last decade has seen an increased scientific interest in the extraction of lipids from microalgae for the production of biodiesel. Microalgae present many advantages compared to other energy crops including a high growth rate, a high biomass production, and noncompetititon with human food production. For economical and ecological reasons the byproducts resulting from the microalgae culture have to be valorized. The Algoroute project is based on the valorization of byproducts resulting from the microalgae production. Could they be used as a binder for aggregates ? In that context, the nature and composition of those byproducts need to be indentified and rheological properties of different nature of compounds need to be measured. Interesting preliminary results have been obtained. Several fractions from microalgae have been extracted and characterized by infrared (IR), nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS). The complex modulus was also determined on these different fractions.