TY - JOUR
T1 - Effect of different grade levels of calcined clays on fresh and hardened properties of ternary-blended cementitious materials for 3D printing
AU - Chen, Yu
AU - Romero Rodriguez, Claudia
AU - Li, Zhenming
AU - Chen, Boyu
AU - Copuroglu, Oguzhan
AU - Schlangen, Erik
PY - 2020
Y1 - 2020
N2 - This study aims to investigate the influences of different grades of calcined clay on 3D printability, compressive strength (7 days), and hydration of limestone and calcined clay-based cementitious materials. Calcined clays that contained various amounts of metakaolin were achieved by blending low-grade calcined clay (LGCC) and high-grade calcined clay (HGCC) in three different proportions. The results revealed that increasing the HGCC% ranging from 0 wt% to 50 wt% in calcined clay could: (1) increase the flow consistency; (2) impressively improve the buildability, and reduce the printability window of the fresh mixtures; (3) enhance and accelerate the cement hydration. The reduction of mean interparticle distance induced by increasing HGCC% may be the primary reason for the enhancement of buildability and very early-age hydration. However, increasing HGCC% led to an increase of air void content in the interface region of the printed sample, which weakened the compressive strength of the printed sample at 7 days. Besides, it confirmed that the cold-joint/weak interface was easily formed by using the fresh mixture with a high structuration rate.
AB - This study aims to investigate the influences of different grades of calcined clay on 3D printability, compressive strength (7 days), and hydration of limestone and calcined clay-based cementitious materials. Calcined clays that contained various amounts of metakaolin were achieved by blending low-grade calcined clay (LGCC) and high-grade calcined clay (HGCC) in three different proportions. The results revealed that increasing the HGCC% ranging from 0 wt% to 50 wt% in calcined clay could: (1) increase the flow consistency; (2) impressively improve the buildability, and reduce the printability window of the fresh mixtures; (3) enhance and accelerate the cement hydration. The reduction of mean interparticle distance induced by increasing HGCC% may be the primary reason for the enhancement of buildability and very early-age hydration. However, increasing HGCC% led to an increase of air void content in the interface region of the printed sample, which weakened the compressive strength of the printed sample at 7 days. Besides, it confirmed that the cold-joint/weak interface was easily formed by using the fresh mixture with a high structuration rate.
KW - 3D concrete printing
KW - Calcined clay
KW - Compressive strength
KW - Hydration kinetics
KW - Sustainability
KW - Ternary-blended cementitious materials
UR - http://www.scopus.com/inward/record.url?scp=85087759747&partnerID=8YFLogxK
U2 - 10.1016/j.cemconcomp.2020.103708
DO - 10.1016/j.cemconcomp.2020.103708
M3 - Article
SN - 0958-9465
VL - 114
JO - Cement and Concrete Composites
JF - Cement and Concrete Composites
M1 - 103708
ER -