Assessment of X-Salt characterization: a salt-based construction material using natural adhesives for additive manufacturing

Purpose

Despite the dramatic increase in construction toward additive manufacturing, several challenges are faced using natural materials such as Earth and salt compared to the most market-useable materials in 3D printing as concrete which consumes high carbon emission.

Design/methodology/approach

Characterization and mechanical tests were conducted on 19 samples for three natural binders in dry and wet tests to mimic the additive manufacturing process in order to reach an efficient extrudable and printable mixture that fits the 3D printer.

Findings

Upon testing compressive strength against grain size, compaction, cohesion, shape, heat and water content, X-Salt was shown to record high compressive strength of 9.5 MPa. This is equivalent to old Karshif and fire bricks and surpasses both rammed Earth and new Karshif. Material flow analysis for X-Salt assessing energy usage showed that only 10% recycled waste was produced by the end of the life cycle compared to salt.

Research limitations/implications

Findings are expected to upscale the use of 3D salt printing in on-site and off-site architectural applications.

Practical implications

Findings contribute to attempts to resolve challenges related to vernacular architecture using 3D salt printing with sufficient stability.

Social implications

Benefits include recyclability and minimum environmental impact. Social aspects related to technology integration remain however for further research.

Originality/value

This paper expands the use of Karshif, a salt-based traditional building material in Egypt's desert by using X-Salt, a salt-base and natural adhesive, and investigating its printability by testing its mechanical properties to reach a cleaner and low-cost sustainable 3D printed mixture.