Title:
Mitigating Plastic Shrinkage of 3D Printed Concrete Using Super Absorbent Polymers
Author(s):
Micah Stark
Publication:
Web Session
Volume:
ws_F25_MicahStark.pdf
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
10/26/2025
Abstract:
3D printed concrete is highly prone to plastic shrinkage. In a previous ACI Research-in-Progress session, Super Absorbent Polymers (SAP) were shown to reduce plastic shrinkage in analog 3D printed concrete filaments. This was attributed to SAP’s potential to retain water and slow evaporation; however, mass loss was not measured. The present study investigates the mechanisms behind SAP-induced shrinkage reduction by simultaneously tracking specimen mass and shrinkage strains. This work extends prior research by measuring deformation along both vertical and horizontal surfaces, enabling analysis of vertical, lateral, and longitudinal strain for approximation of total volumetric strain alongside mass loss. Results show that SAP additive specimens with increased water content experienced greater mass loss yet reduced volumetric shrinkage by up to 40%. This suggests that mechanisms beyond simple water retention, such as delayed capillary pressure development or pore structure alteration, may be contributing to the observed shrinkage mitigation.