Influence of chemical admixture on the properties of porous and draining cement concrete

Porous road surfaces are of primary importance amongst the various alternat ive technologies for urban drainage. However; porous cement concrete, due t o its bad mechanical behaviour, presents law interest as urban paving surfa ce material in road construction. This paper shows that when interactions between the properties of binder an d those of concrete are investigated, all the variables upon which the mech anical behaviour of porous concrete depends are pointed out. The optimisation of these variables allows the following choices: - a silico-calcareous aggregate; - a pozzolanic binder; - an appropriate chemical admixture in order to design a porous and drainin g cement concrete which could be used as a road pavement layer.