New waste-based supplementary cementitious materials: Mortars and concrete formulations. (20th April 2020) - Acordi, J.
Graphical abstract: Highlights: It is possible to add WFA together with pozzolan to obtain a ternary cement. The addition of WFA decreases the compressive strength of the mortar. HWA decreases the elastic modulus and workability of the concrete. The HWA presents reactive behavior in the alkali-aggregate reaction (AAR) test. Abstract: The compressive strength behavior of cement mixtures produced with wood ash was investigated. This ash was characterized to determine its potential as supplementary cementitious materials (SCMs) in Portland Cement (PC) as pozzolanic material (WFA) and as active aggregate (HWA). By assuming the pozzolanic mineral addition content in Portland Cement PC IV as reference, as well as considering WFA with the highest pozzolanic potential, we developed the SCM binder fraction. This was achieved by replacing up to 50 wt% of PC, combining WFA and pozzolan with Portland Cement PC V. By defining the binder fraction along with HWA characterization, concrete compositions replacing up to 30 vol% of the aggregate fraction with HWA were established. The use of WFA reduces the compressive strength, while HWA decreases the elasticity modulus of the produced concretes. Ecoconcrete containing ~17.2 wt% of waste exhibited over 40 MPa after 28 days of curing and high durability.