Jean-Charles Bénézet

Two Typical Plant Aggregates for Bio-Based Concretes

Many by-products of plant origin have been incorporated in mineral binders. However, it is important to distinguish plant fibers used as reinforcement in cement composite materials from plant-derived aggregates used for the manufacturing of lightweight insulating concretes (bio-based concretes).

Lime-Based Binders

Unlike Portland cement, the use of lime goes back much further in time. During the Greco-Roman period, walls were built of lime-based mortars blended with fine sand and pozzolanic additives (volcanic ash).

Conclusion and Outlooks

The results reported in this document first contribute to the development of an innovative plant-based concrete using raw rice husk. This crop residue is available throughout the year at low cost and its use to manufacture bio-based concretes for green building provides a new recovery sector for a local by-product coming from rice farming in France.

Lime and Hemp or Rice Husk Concretes for the Building Envelope: Applications and General Properties

Hemp concrete is obtained from the mix of hemp shiv, water and a mineral binder (which can be itself a mixture of different binders).

Granular self-organisation and reactivity - adsorbates and agglomerates particle size influence

Abstract The aim of this work is to study the organisation of the distributed system and the influence of adsorption and agglomeration phenomena in a dry bi-phase mixture. The studied system is a mixture of silica and carbonate. The parameter of interest is particle size. With the crossover of different fractions of silica and carbonate, it is possible to build a dimensional chessboard and then study the role of dimension in the organisation of distributed system. In these mixtures, several combinations are possible following the particle size. These combinations result from agglomeration and adsorption mechanisms. It is necessary to distinguish self-attractive phenomena (self-agglomeration and self-adsorption) that concern particles of same chemical composition, and inter-attractive phenomena (inter-agglomeration and inter-adsorption) that concern particles of different chemical compositions. The reactivity of the different mixtures treated thermally at 850 °C is measured by X-ray diffraction (DRX). It is estimated by the quantity of produced phases. Then this reactivity is explained by the different attractive phenomena studied.