The present invention relates to an adhesive composition comprising: at least one phosphate salt chosen from sodium phosphate, potassium phosphate and mixtures of these phosphates; and at least one resin based on: at least one compound A1, compound A1 being chosen from a compound A11 comprising at least two functions, one of these functions being a hydroxymethyl function and the other being an aldehyde function or a hydroxymethyl function, or a compound A12 comprising at least one aldehyde function, or a mixture of a compound A11 and of a compound A12; and at least one phenol A21.