Use of wood ash as a substitute for fine aggregate in the production of lightweight concrete

Abstract

The present study proposes the use of wood ash as a partial substitute for fine aggregate, for which a base concrete of 180 kg/cm² and concretes with 30, 50 and 70% replacement were proposed. Laboratory tests were carried out on all concrete components such as: granulometry, real and apparent density, absorption capacity with a sample of 36 cylindrical specimens evaluated at 7, 14 and 28 days. Subsequently, an analysis was made of the real hardened density and compressive strength, the results of which showed the influence of wood ash on these properties. The densities of 2233.75 kg/m³, 2210.38 kg/m³ and 2176.96 kg/m³ that decrease progressively according to the replacement percentages do not allow a classification within the light concretes because the considered limit of 2000 kg/m³ is exceeded. With respect to the compressive strength, which shows a decrease, it was determined that in order to comply with the design, the replacement will not exceed 30%. In short, this concrete could be used in the construction of sidewalks and curbs, prefabricated masonry constructions used in the division of environments and for cyclopean concrete.