Influence of curing procedures and porosity in the flexural resistance of concretes for paving

Flexural strength of high performance concrete submitted to several non-standard curing conditions was evaluated through bending tests on beams in order to allow comparisons among different curing procedures. The moist curing process resulted more effective than curing by chemical products leading to membrane formation over concrete surface; moreover, flexural strength of high strength concrete was increased when satu- rated specimens were tested, whereas conventional concrete flexural strength decreased when submitted to the same conditions. Such results were explained on the basis of concrete porosity with the support of air permeability tests. Results explained differences between the behavior of conventional and high strength concrete when water fills the specimen pores. As recommendation, high strength concrete specimens shall not be tested in bending in saturated condition under the risk of overestimation of flexural resistance.