Investigation on geometric and surface finish quality of 3D concrete printed walls with hollow section

Abstract

3D concrete printed walls with hollow sections are now widely adopted in 3D concrete printing applications across the construction industry. One of the significant challenges in the printing process is achieving superior surface finishes. Previous research has predominantly focused on the overall geometry of these walls, often neglecting surface finish quality at the intersections of formwork and supporting filaments. This study is dedicated to optimizing the geometric arrangement of supporting filaments and enhancing print quality at these critical intersections. Firstly, two arrangement strategies, the standard approach and the average approach, are introduced to establish high-quality geometric section configurations, with practical demonstrations on both rectangular and arc-shaped walls. Subsequently, the width of concrete filaments is considered to enhance surface finish quality at the intersections. Two print quality control methods, namely the e- Δ control rule and the r- Δ control rule, are then developed. To assess the effectiveness of these arrangement strategies and control methods, configurations of walls with specific dimensions are compared, and printing experiments are conducted. Finally, recommendations for practical application are provided, aimed at improving both the geometric and surface finish quality of 3D concrete printed walls with hollow sections.