Addition of biomass ash in concrete: effects on E-Modulus, electrical conductivity at early ages and their correlation

Abstract

This research aims to study the influence of biomass ashes in the evolution of E-Modulus at an early age (0–7 days) in concretes with different percentages of replacement of cement by biomass ash (0%, 15% and 30%). Its behaviour was evaluated through the continuous monitoring of the E-Modulus method as well as using a NDT: measurement of internal electrical conductivity. Whereas at 7 days the influence of a replacement of 15% of biomass ash on E-Modulus is negligible, during the first day the negative influence is very important, with values of loss of E-Modulus higher than 70%. The influence of the biomass ash in the evolution of internal electrical conductivity suggests that the biomass ash could reduce the chloride ion penetration resistance, even in concrete with 15% of biomass ash that did not induce a decrease of the E-Modulus at 7 days. The influence of the biomass ash in the correlations of E-Modulus and electrical conductivity has been studied. Maturity corrections were made.