Title:
Biochar to Enhance Curing and Rheology of Mortars without Formwork
Author(s):
Devid Falliano, Luciana Restuccia, Jean-Marc Tulliani, and Giuseppe Andrea Ferro
Publication:
Materials Journal
Volume:
122
Issue:
4
Appears on pages(s):
89-98
Keywords:
biochar; internal curing agent; mechanical properties; rheological properties; three-dimensional (3-D) concrete printing
DOI:
10.14359/51746809
Date:
7/1/2025
Abstract:
Biochar properties—in particular, its fineness and ability to absorbwater—can be exploited to modify the rheological behavior ofcementitious conglomerates and improve the hydration of cementpaste under adverse curing conditions, such as those related tothree-dimensional (3-D) concrete printing. Regarding the freshstateproperties, the study of rheological properties, conductedon cementitious pastes for different biochar additions (by weightof cement: 0, 1.5, 2, and 3%), highlights that the biochar inducesan increase in yield stress and plastic viscosity. The investigationof mechanical properties—in particular, flexural and compressivestrength—performed on mortars evidences the internal curingeffect promoted by biochar additions (by weight of cement: 0, 3,and 7.7%). In fact, compared to the corresponding specimens curedfor the first 48 hours in the formwork, specimens with biochar addition cured directly in air are characterized by a drastically lowerreduction in compressive strength than the reference specimens—that is, approximately 36% and 48%, respectively. This interestingresult can also be exploited in traditional construction techniqueswhere faster demolding is needed.