Characterization of a lateritic geomaterial and its elaboration through a chemical route

The development of a laterite-based geomaterial, mimicking naturally occurring concretions in lateritic soils, through a chemical route has been investigated in this paper. The elaboration process involves an acidic dissolution reaction of iron compounds followed by a neutralization reaction with a strong base. The first step needs a 24 h reacting time before adding the base. Afterwards, the consolidation that involves an iron-bonding of the particles, is performed at 60 °C for 18 days under water-saturated atmosphere. The products elaborated using nitric acid and calcium hydroxide exhibit the best characteristic compressive strength, namely 20 MPa and a good resistance towards water seeping and wearing. Nevertheless, the use of fulvic acid, an organic ecological acid, leads to a water-resistant geomaterial with a good characteristic compressive strength of 12 MPa, thus competitive towards usual stabilized earth and concrete building materials.