Title:
Biochar to Enhance Curing and Rheology of Mortars without Formwork (Prepublished)
Author(s):
Devid Falliano, Luciana Restuccia, Jean-Marc Tulliani and Giuseppe Andrea Ferro
Publication:
Materials Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
3-D concrete printing; biochar; internal curing agent; mechanical properties; rheological properties
DOI:
10.14359/51746809
Date:
5/8/2025
Abstract:
Biochar properties, in particular, its fineness and its ability to absorb water, can be exploited to modify the rheological behaviour of cementitious conglomerates and to improve the hydration of the cement paste under adverse curing conditions such as those related to 3D concrete printing. Regarding the fresh state properties, the study of the rheological properties conducted on cementitious pastes for different biochar additions (by weight of cement: 0%, 1.5%, 2%, and 3%) highlights that the biochar induces an increase in yield stress and plastic viscosity. The investigation of mechanical properties, in particular flexural sand compressive strength, performed on mortars, evidences the internal curing effect promoted by biochar additions (by weight of cement: 0%, 3%, and 7.7%). In fact, compared to the corresponding specimens cured for the first 48 hours in the formwork, specimens with biochar addition cured directly in air are characterised by a drastically lower reduction in compressive strength than the reference specimens, i.e., approximately 36% and 48% respectively. This interesting result can also be exploited in traditional construction techniques, where faster demolding is needed.