Improving interlayer bond of 3D printed concrete with modified cement paste

Abstract

3D printed concrete is a completely new technology, it was developed rapidly into a technique used to benefitin the construction industry. But besides that, 3D concrete printing technology still has some limitations. In which, interlayer bond of 3D printed concrete is considered the weakest point, the main cause is due to the drycontact surface and the appearance of voids on the interlayer surface affecting the mechanical properties. This paper presents an investigation that offers a solution to improve interlayer bond of 3D printed concrete byusingfour various cement pastes forming bond interface for the 3D printed layer to increase bond strength and minimize voids. The characteristics of flow, compressive strength, pull-off adhesion strength also measured toinvestigate and analyze the correlation of interlayer bond strength of 3D printed concrete to understand the adhesion mechanism. The results show that the samples using Sikament R7N additives has the highest interlayerbond strength. In contrast to the samples using Sika Latex TH had lower results than the control sample.