Work

Short-fiber-reinforced structural silicone for facades: Potential & performance

Year: 2025

Type: article

Abstract: Silicones are elastic sealants and adhesives. They are able to compensate for unevenness and temperature longitudinal expansions between various joining materials. In accordance with the requirements of ETAG 002-1, these adhesives combine the optimal weather and UV resistance with very good adhesion. As a result, they are the only adhesives suitable for structural use in bonded façades. In comparison with other elastic adhesives (e.g., polyurethanes, silane-modified polymers), the Young´s modulus (< 0.9 - 3 MPa) and the design stress in tension (< 0.2 MPa) are low. The consequences are a high deformation of the bonding under loads or low transferable loads. It should also be noted that approved high modulus silicone adhesives do not show significant improvement in the relevant material properties.Analogous to the effect of fiber-reinforced plastics, where a load is transferred from the polymer matrix to the fibers, the specific use of yarns, cords and fabrics in elastomers already enables high-performance composite materials for conveyor belts, tires and tubes. It is hypothesized that this effect can be transferred by using short fibers to create reinforced structural silicone adhesives (FRSSG). This could potentially allow the mechanical properties of the material to be optimized according to the requirements of a specific application. This article investigates the possibilities and technical risks associated with mixing short fibers into 2K silicone adhesives for use in the building industry. This study includes 280 test specimens with 8 different short fibers or fillers, each in 3 different proportions. A wide range of natural or industrial fibers have different effects on the mechanical properties of a silicone adhesive. For instance, cotton fibers have been shown to enhance adhesive stiffness by a factor of between 50% and 500% (tensile test, DIN EN ISO 527) and increase the strength by 5% to 30% (adhesion test, ETAG 002-1). This opens up interesting applications and great research potential.

Source: International Journal of Adhesion and Adhesives

DOI: 10.1016/j.ijadhadh.2025.104220

Authors: Michael Engelmann, Johannes Giese-Hinz, Silke Tasche

Institution: Technische Universität Dresden

Language: English

Topic: Structural Analysis of Composite Materials

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Industry, innovation and infrastructure

Open Access status: hybrid

Estimated APC paid: $3,760