Impact of hemp shiv on cement setting and hardening: Influence of the extracted components from the aggregates and study of the interfaces with the inorganic matrix

• Published in: Cement & concrete composites 2015-01, Vol.55, p.112-121
• Main Authors: Diquélou, Youen, Gourlay, Etienne, Arnaud, Laurent, Kurek, Bernard
• Format: Article
• Language: English
• Subjects: Aggregates; Cement; Cements; Chemical and Process Engineering; Construction; Engineering Sciences; Environmental Sciences; Food engineering; Hardening; Hemp; Hydration; Insulation; Interface; Life Sciences; Markets; Mechanical properties; Retardation; Setting (hardening)
• ISSN: 0958-9465; 1873-393X
• DOI: 10.1016/j.cemconcomp.2014.09.004

The need for efficient building insulation with low environmental impact has led to a growing market for hemp lightweight concretes. However, a deeper understanding of the interactions between hemp particles and binders during the setting and hardening phase is needed to meet required industrial specifications. In this paper, the effects of three types of shiv and their corresponding water extracts on cement setting are compared. Various analyses show that these extracts delay hydration, thereby negatively affecting the mechanical properties of the cement. A comparison of the chemical composition of shiv water extracts highlights the importance of plant quality and the variability of their effects on cement. The development of a new methodology, combined with the use of 13C labeled plant material, made it possible to closely monitor the physiochemical phenomena occurring at the plant aggregate and cement matrix interface.