Open AccessSurface modification as a technique to improve inter-layer bonding strength in 3D printed cementitious materials
Author(s) -
Jolien Van Der Putten,
Geert De Schutter,
Kim Van Tittelboom
Publication year - 2019
Publication title -
rilem technical letters
Language(s) - English
Resource type - Journals
ISSN - 2518-0231
DOI - 10.21809/rilemtechlett.2019.84
Subject(s) - materials science , composite material , surface roughness , layer (electronics) , substrate (aquarium) , cementitious , bond strength , bonding strength , compressive strength , surface finish , cement , adhesive , oceanography , geology
The structural capacity of 3D printed components mainly depends on the inter-layer bonding strength between the different layers. This bond strength is affected by many parameters (e.g. moisture content of the substrate, time gap, surface roughness,..) and any mismatch in properties of the cementitious material may lead to early failure. A common technique to improve inter-layer bonding strength between a substrate and a newly added layer is modifying the substrate surface. For the purpose of this research, a custom-made 3D printing apparatus is used to simulate the printing process and layered specimens with a different delay time (0 and 30 minutes) are manufactured with different surface modification techniques (wire brushing, addition of sand or cement and moisturizing substrate layer). The surface roughness was measured and the effect of the modification technique on the inter-layer-bonding strength was investigated. Results showed that the most effective way to increase the inter-layer bonding is increasing the surface roughness by a comb. This creates a kind of interlock system that will provide a higher inter-layer strength. The compressive strength is most influenced by the addition of cement, where the changing W/C-ratio will create a higher degree of hydration and consequently a higher strength.