Rheological and Water Transport Properties of Cement Pastes Modified with Diutan Gum and Attapulgite/Palygorskite Nanoclays for 3D Concrete Printing

摘要

This paper identifies and addresses two challenges in extrusion-based 3D concrete printing from a materials perspective.The first is the effect of self-weight and the weight of subsequent layers on structural build-up.And the second is the excessive water loss of printed materials due to the absence of formwork.Viscosity modifying admixtures(VMAs)are extensively used in cement-based 3D printing projects to achieve sufficient print quality,shape stability,and printability window.This study aims to evaluate VMAs’effects on the two aforementioned challenges through investigating the evolution of static yield stress under sustained stress at rest and water retention capacity of cement pastes modified with nanoclay and diutan gum.