The research project „Robotic fabrication of rammed earth elements“ aims, to develop an applicable, robotic manufacturing process for rammed earth components. Rammed earth is an ancient building technique used since 8000 years. The technique is based upon layered compaction of earth in a formwork by using a manually driven wooden tamper. Today formwork technology is improved and pneumatic tampers replaced hand tampers. However, the process is still manual in nature, which leads to inefficiencies compared to other building materials and techniques. In contrast to concrete, where stability depends on a chemical reaction, rammed earth gains its fundamental stability merely from the compaction process. Therefore, a formwork is only needed, where compaction takes place immediately. In contrast to the traditional technique, the objective in this research project is the development of an actively moved formwork and a compaction tool that is mounted as an end effector to a robot.
The assumptive benefits investigated in this research project are a higher precision, consistent quality and economic advantages compared to the manual process.
Project leader at ITE:
Prof. Dr. Ing. Harald Kloft
ITE - Institut für Tragwerksentwurf TU BS
04/2019 - 03/2022
Bundesinstitut für Bau-, Stadt-, und Raumforschung; Zukunft Bau
Project Aims/ Working program
The steps of the working program lead to the realisation of a demonstrator in sclae 1:1. The demonstrator shows how the process is working and that rammed earth is able to compete with industrialised and well-established building materials.
The working program is divided into the following steps:
Designation of material properties
Development of a suitable compaction method
Development of tools for compaction and material feeding
Development of an automated process
Programing and implementation of a digital process chain at DBFL
Realisation of a demonstrator and documentation
Economic evaluation and market potential
Dokumentation and publication of results
The research project is based on the concept of a student project, that was developed during „Digital Fabrication Studio“, an experimental research-seminar at ITE for architecture students at TU Braunschweig. The concept of fabricating rammed earth with an actively moved slipform in combination with a rammer was tested manually (Fig. 1) and with the use of a UR-5 Robot (Fig. 2) in small-scale experiments.
The experiments proofed the feasibility of the overall concept and stated challenges such as material feeding and face side sheating, for an upscaled process.
Digital and physical process testing is carried out at the Digital Building Fabrication Laboratory (DBFL) at TU Braunschweig. The influences of different process parameters on the results are tested and measured by creating and evaluating test specimen. The engineering of tools plays a major role in this research project and is done in determined workshops at TU Braunschweig.