Hormigón de bajas propiedades resistentes reforzado con ffbras de polioleffna: consideraciones y diseño de un hormigón estructural competitivo

Abstract

Polyoleffn ffbre reinforced concrete (PFRC) has become an attractive alternative to steel ffbre reinforced concrete for structural applications. Although PFRC has shown capacity for meeting the structural requirements set in the regulations sometimes, complying with the residual strength value at 0,5mm of crack opening (f R1 ) might be a challenge. That value is aimed at avoiding brittleness of the concrete element and in certain occasions require ffbre dosages close to 6kg/m³. Most of the previous studies have been performed with normal or high quality concretes and consequently their strength at the end of the limit of proportionality (f LOP ) is also remarkable. Given that the residual strength at f R1 is set as a proportional value of f LOP performing a concrete with lower mechanical properties would allow production of one that encountered fewer issues related with brittleness and offered improvement in tensile and ffexural strength at a reduced cost. In this study, several concretes with reduced mechanical properties and with 6 and 7,5kg/ m³ of polyoleffn ffbres were manufactured. Their mechanical response was analysed in order to determine if they were apt for their use in low responsibility structural concrete members. Moreover, the inffuence of the method used to add the ffbres was studied by adding the ffbres in two different ways adding them individually from sacks or using pucks (50g each one).