Plastic shrinkage cracking in 3D printed concrete

By G. M. Moelich, J. Kruger, R. Combrinck. 2020

197 citations recorded by the source corpus.

Abstract In concrete, early age pore water evaporation results in volumetric shrinkage that, if restrained, can cause plastic shrinkage cracking (PSC). 3D printed concrete (3DPC) is vulnerable to PSC due to a lack of formwork, minimal bleeding water, low aggregate to binder ratio and high quantities of fines in the mixture. A novel experimental method was developed to determine the PSC risk, evaluating the efficacy of PSC prevention measures and understanding the behaviour of PSC in early age 3DPC. This study evaluated the free shrinkage of 3DPC specimens as well as identified and systematically introduced sources of restraint to induce PSC. The free shrinkage results showed a rate of strain gain and peak strain significantly higher than commonly found in ordinary concrete. Severe cracking was observed when the shrinkage was restrained under a moderate evaporation rate. Cracks formed within the first 2 h after printing, earlier than in ordinary concrete. The proposed method was employed to study the fundamental behaviour of crack formation and propagation in 3DPC. The unique filament interlayer plane has a notable effect on the transfer of shrinkage deformation in the specimen. Differential horizontal deformation in consecutive layers and consequential interlayer slip was observed when the shrinkage was restrained. It is reasonable to conclude that interlayer slip caused by early age shrinkage has the potential to reduce the long-term interlayer bond strength and the durability of 3DPC.

Subfields: Building and Construction, Civil and Structural Engineering

View Paper: https://www.semanticscholar.org/paper/beb52e7b7e3690867bab060dd63595514580fdd8

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Building and Construction

1. Z. Duan
2. Jianzhuang Xiao
3. Shaodan Hou
4. Jun Ye
5. Jorge de Brito
6. Chi-Sun Poon

In Civil and Structural Engineering

1. Z. Duan
2. Shaodan Hou
3. Jun Ye
4. Jianzhuang Xiao
5. Jorge de Brito
6. Chi-Sun Poon

Citations in the corpus

• A review of 3D printed concrete: Performance requirements, testing measurements and mix design (2020, background): “There is a risk of plastic cracking for the fresh 3DPC due to lack of curing, especially in severe environments, such as hot and windy conditions [62,63].”