Antonin Fabbri

Ecole Nationale des Travaux Publics de l'Etat | ENTPE · LTDS

A poromechanical model is developed to identify how chemical reactions of carbonation may impact the mechanical behaviour of wellbore cement in the context of CO2 storage. The model enables the evaluation of pore overpressure, porosity and solid-skeleton strain evolutions during the carbonation process. The major chemical reactions occurring within...

The goal of this paper is to investigate the validity of indirectly built ice content curves from porous network characterization tests to predict the behavior of a freezing cement based material. To do so, the results obtained by the two classical methods, namely the mercury intrusion porosimetry (MIP) and the gravimetric water desorption (WD) tes...

The goal of this paper is to identify the effects of liquid water and water vapor in-pore transports as well as phase changes on the hygrothermal behavior of earthen buildings. Indeed, one of the main assets used to promote these constructions is their role in moisture buffering hence temperature and relative humidity quality controlling. However,...

This paper presents a novel process to recycle the fine fraction of ground concrete waste as a construction binder. The fine fraction of ground concrete is rich of partly hydrated cementitious products, whose binding capacity is further enhanced by treatment at relatively moderate temperatures. The viability of the recycled binder has been demonstr...

Under cold climate, poral water of building materials can be exposed to freezing-thawing (F-T) cycles that induce severe frost damage and jeopardize their durability. The F-T curve (variation in ice or unfrozen liquid content with negative temperatures) is a key property to examine and predict the behavior of porous materials under freezing tempera...

To mitigate the anthropogenic greenhouse gas emissions from the operational energy consumption in buildings, increasingly high-performance envelopes are developed. A reduction in indoor air renewal is observed that leads to a higher pollutant concentration in the built environment. Particular attention was given to CO 2 , an anthropogenic gas that...

Earthen constructions can experience severe damage under coupled action of moistening and freezing-thawing (F-T). This paper proposes an experimental study on the F-T behavior of earthen samples at different liquid saturation degrees (SL0). Normal moisture conditions during winter were investigated using two values of relative humidity (RH): RH = 7...

Cette étude propose d'évaluer l'effet de la saturation liquide et du chargement axial sur les déformations au gel-dégel d'un matériau terre non-saturé. Des contraintes axiales de 0 et de 100 kPa ont été appliquées sur des échantillons conditionnés à trois saturations liquides initiales différentes. Les résultats montrent que le chargement mécanique...

To determine the water vapour permeability of porous building materials, the wet cup and dry cup tests are frequently performed. Those tests have shown to present high discrepancy. The water vapour permeability of building materials is an essential parameter to determine the hygrothermal behaviour of the material and its impact on indoor comfort. S...

This paper deals with the experimental assessment of the influence of water content on thermal conductivity, thermal effusivity, heat capacity and vapor permeability of pith and hemp shiv composites. The results, which will be used to enrich modelling databases, show that all four properties increase their value with relative humidity , especially...

This paper focuses on investigating how a particular but classical configuration of a finite homogeneous soil layer, once studied by Terzaghi and currently subjected to freezing temperatures, behaves and how different boundary conditions can intervene and affect the thermo-hydro-mechanical (THM) responses. Spatial homogeneity is a strong assumption...

Rammed earth (RE) as a construction material fits perfectly into the circular economy concept as the soil is usually taken from excavation works (a waste) and is upcycled to build earthen architecture without adding any other components (unstabilised RE). RE is therefore recoverable at the building end-of-life. For non-common buildings, it is cruci...

Based on the RILEM Technical Committee 274-TCE work, this paper is a discussion of the remaining engineering challenges faced by earthen architecture. The assessment of earth material performances requires the development of appropriate procedures and standards. This is discussed in particular for the characterisation, hygrothermal behaviour, mecha...

Earth is a building material excavated from the subsoil which is employed by Mankind since the Neolithic time all over the world. Various building techniques are used with earth, to build monolithic walls, to produce bricks, as infill of walls or as plasters or mortars. Earth architectures undergo a rebirth since the 2000s because they are a way to...

This chapter reviews the potential impact of six environmental agents (water, ice, wind, fire, solar radiation and chemical attack) on the long-term stability of earth buildings together with some of the most common techniques for measuring and improving material durability. Liquid water appears the most detrimental of all environmental agents, not...

Thanks to their microstructure which allows both exchange of gas with their surrounding environment and internal water vapour sorption phenomena, earthen materials are highly hygroscopic. If no material is used as a barrier or retardant to the diffusion into the envelope between the earth and the indoor environment of a building, they have a great...

This book presents the work done by the RILEM Technical Committee 274-TCE. It focuses on the estimation of the parameters which are necessary to properly design earthen constructions. It provides a compilation of the value classically obtained for the key parameters of earthen materials, a pedagogical presentation of the main testing procedures for...

The need for a vast quantity of new buildings to address the increase in population and living standards is opposed to the need for tackling global warming and the decline in biodiversity. To overcome this twofold challenge, there is a need to move towards a more circular economy by widely using a combination of alternative low-carbon construction...

The aim of this work is to assess the durability of stabilized and unstabilized compacted earth toward water. To do so, three common laboratory testing methods were selected to evaluate their effectiveness in delivering consistent information on the durability of the earthen product. They consist of the “wet to dry strength test”, the “accelerated...

Bio-based materials are an environmentally friendly alternative to classic construction materials, yet their generally low density can lead to poor acoustic properties. The acoustic performance of hemp shiv and sunflower pith composites is therefore analyzed using Kundt's tube. Although the loose aggregates present an exceptional sound absorbing be...

Cement is a common candidate for soil treatment when stabilization is required. Its employment in compacted earth blocks requests curing the product as efficiently as possible to obtain satisfactory performances. In this context, many practitioners’ recommendations exist. However, no studies have stated clearly optimum curing method required to ach...

Earth plasters are a very interesting solution for the coating of earthen construction, in terms of embodied energy, technical efficiency, while keeping the hygroscopic properties of the wall, unlike very little permeable coatings, as the cement-based ones. An experimental campaign has been conducted on several earth plasters which differs by their...

This paper investigates the compaction characteristics of raw earth via a double-faced static compaction and the traditional Proctor test (dynamic process). The corresponding compaction energies are estimated for each individual sample, while the matric suctions are measured by a simple method using filter papers. The obtained results allow to draw...

The experimental characterization of most of the hygrothermal properties of bio-based porous materials, which are characteristic for their double-scale porosity, requires for the samples to stabilize their liquid water content. Furthermore, such measurements often take several weeks to several months. In contrast, acoustical measurements can be rea...

The use of earth as a building material is worldwide encouraged thanks to its low environmental impact and its high hygrothermal performances. In wet and cold regions, the durability of earthen constructions is a major preoccupation because of water attack and frost damage. The variety of raw earth, compaction method and exposition to water increas...

Abstract: The experimental characterization of most of the hygrothermal properties of bio-based porous materials, which are characteristic for their double-scale porosity, requires for the samples to stabilize their liquid water content. Furthermore, such measurements often take several weeks to several months. In contrast, acoustical measurements...

In the European Union, most of the wastes from the building sector are composed of earths. Earth construction may be an interesting outlet for the re-use of these wastes, while meeting the challenge of circular economy: in particular, it involves low-embodied energy processes and earth material can be re-used for building by end-of-life. Nonetheles...

Due to the environmental impact of building materials, researches on sustainable materials, such as bio-based and earth materials, are now widespread. These materials offer numerous qualities such as their availability, recyclability and their ability to dampen the indoor relative humidity variations due to their hygroscopicity. As these materials...

Rammed earth is a monolith structure constructed by compacting partially saturated soil in layers within a formwork. Few studies have pointed out the lack of experimental data on rammed earth layer interface strength and their importance in design consideration. Currently available testing procedures such as shear box, triaxial, triplet, push-over...

The hygroscopic behavior of earthen materials has been extensively studied in the past decades. However, while the air flow within their porous network may significantly affect the kinetics of vapor transfer and thus their hygroscopic performances, few studies have focused on its assessment. For that purpose, a key parameter would be the gas permea...

The plant aggregates used for the production of bio-based mortars and concretes, present a natural variability due to their geographical origin, climatic conditions and the year of harvest. This variability might be a problem for the promotion of such materials if it significantly impacts the performance of the final product. To investigate such in...

The use of raw earth as a building material is gaining interest, indeed raw earth has considerable environmental advantages. However, the correct use and development of such materials requires an accurate assessment of the water content within the walls during service life, since this latter strongly impacts both their mechanical and thermal proper...

Experimental investigations were carried out in this work to evaluate the impact of stabilization on the mechanical and hygric properties of a reference soil-cement couple. Unstabilized and stabilized soils with two amounts of cement were examined. Compacted earth samples were prepared at their optimum water content and dry density. The effectivene...

The plant aggregates used for the production of bio-based mortars and concretes, present a natural variability due to their geographical origin, climatic conditions and the year of harvest. This variability might be a problem for the promotion of such materials if it significantly impacts the performance of the final product. To investigate such in...

Entrapped air in porous media A B S T R A C T Near saturation, air bubbles and pockets can be trapped in the porous network of soils. The aim of this paper was to present a coupled model that takes into account the effect of this entrapped air on the poro-elasto-plastic behavior of the soil. The model takes into account the physical-mechanical inte...

The article Modelling the poroplastic damageable behaviour of earthen materials, written by Longfei Xu, Henry Wong, Antonin Fabbri, Florian Champiré and Denis Branque, was originally published online without Open Access. After publication in volume 51, article ID 112 RILEM decided to grant the author to opt for open choice and to make the article a...

The use and development of earth as a building material is notably constrained by its specific thermal and mechanical behaviours in relation to water, currently not considered in construction norms and technical guides. As the compressive strength decreases with the presence of water in pores, a good prediction of water content evolution within ear...

The article Effect of temperature on the sorption curves of earthen materials, written by Fin O’Flaherty, Antonin Fabbri, Fionn McGregor, Ines Costa, Paulina Faria, was originally published online without Open Access.

The hydromechanical behaviour of compacted earth samples was experimentally analysed with a triaxial apparatus at controlled hygrometry and temperature. The results show that the relative humidity at which the samples were stored have a strong impact on the mechanical characteristics of earthen material: both the maximum deviator stress and Young’s...

After being almost abandoned at the end of the Second World War, the use of raw earth is currently regaining the interest of architects, engineers and policy makers for the construction of dwellings in industrialised countries. This renaissance is driven by growing ecological awareness and the promotion of construction techniques that minimize ener...

The use and development of earth as a building material is notably constrained by its specific thermal and mechanical behaviours in relation to water, currently not considered in construction norms and technical guides. As the compressive strength decreases with the presence of water in the pores, a better understanding of the material behavior at...

A set of tests is proposed to contribute to the experimental identification of the failure surfaces of an elasto-plastic model for a rammed earth along different stress paths such as compression, extension and tensile stress paths. The constitutive model involves two failure surfaces reflecting two different modes of failure within the material, a...

This paper presents a new constitutive model on the poroplastic behaviour of earthen materials accounting for stiffness degradation, using the approach of continuum damage mechanics. The poroplastic behaviour is modelled based on the bounding surface plasticity (BSP) theory and the concept of effective stress while isotropic damage is modelled usin...

This paper investigates the impact of clay and moisture contents on the shear behavior of compacted earth taking into account loading-unloading cycles. Fine sand was added to a natural soil, thereby obtaining three different soils with clay contents of 35%, 26%, and 17%, respectively. A series of triaxial tests was conducted on samples previously e...

The rehabilitation of ancient rammed earth houses, as well as the use of earthen materials in modern constructions, are a growing matter of concern, especially in area such as Rhône-Alpes, France, where 40% of old constructions are in rammed earth. A current pathology observed for this type of construction is related to the rising damps, for which...

Due to their various applications in geo-environmental engineering, such as in landfill and nuclear waste disposals, the coupled chemo-hydro-mechanical analysis of expansive soils has gained more and more attention recently. These expansive soils are usually unsaturated under field conditions; therefore the capillary effects need to be taken into a...

Hemp concrete is a sustainable material with low embodied energy. However, its development as a building material requires a better evaluation of its moisture-thermal buffering abilities behavior, which are known to strongly depend on the amount of water contained in wall pores and its evolution. In this context, the aim of this paper is to study t...

Unfired earth is a sustainable construction material with low embodied energy, but its development requires a better evaluation of its moisture–thermal buffering abilities and its mechanical behavior. Both of them are known to strongly depend on the amount of water contained in its porous network and its evolution with external conditions (temperat...

In the global will of reducing fossil energy consumption and greenhouse gas emission in the building sector, the use of bio-based insulating materials is gaining interest thanks to their profitable properties and their suitability for the renovation of ancient buildings made out of unconventional materials. However, such materials are still lacking...

Hygrothermal analysis of building envelopes requires high-quality input data and thoroughly tested models. To improve a model developed in Comsol Multiphysics for assessing the hygrothermal performance of rammed earth constructions, flexible dynamic small-scale experiments are presented. First, an experimental study shows the sample production, tes...

The experimental determination of dynamic mass transfer properties of porous materials such as eco-efficient clay plasters is greatly influenced by the convective conditions at the surface of the material during the test. The measurement of the intrinsic vapour permeability of highly porous materials has shown to present wide discrepancies when the...

In order to explore the hydro-thermo-mechanical behaviour of compacted earth, triaxial apparatus at controlled temperature and equipped with non-contacted sensors measuring system, was developed. The results show that the relative humidity at which the samples were stored have a strong impact on the mechanical characteristics of earthen material: b...

The aim of this study is to assess the mechanical behavior of earthen materials when submitted to spatial and temporal variations of temperature and hygrometry. The first step of this study is to quantify the effects of heat and mass transports, including the phase changes occurring within the pores, on the hygrothermal behavior. This information i...

Available throughout the world and used in construction for thousand years, earthen materials are known to improve indoor air quality while keeping the internal temperature relatively stable. In Rhône-Alpes, France, the rammed earth technic is the most spread and consists in compacting layers of earth, one by one, within a framework. Current therma...

This chapter introduces the case of the earthen constructions including most of the techniques used in the vernacular heritage and the modern green building architecture. It starts by presenting the variety of earth building techniques focusing on the common points between all of them. It then explains these particularities which are linked to the...

This paper presents a constitutive model for unsaturated soils, based on the non-associate bounding surface plasticity concept under a critical state framework. With a limited number of parameters, this model allows removing the sudden stiffness reduction at the on-set of plastic strains when the stress reaches the yield surface. It also enables to...

Earth is a predominant eco-friendly construction material which provides a good occupational comfort consuming less energy. To improve the durability performance, stabilization is commonly adopted. However the additional costs induced by such process cannot be afforded by the majority of the population in developing countries, and in some circumsta...

Rammed earth was traditionally used in western European countries before industrial building materials replace it during 20th Century. Construction strategies developed by former builders were dictated by locally available construction materials and engendered local constructive cultures. Unfortunately, this knowledge was orally transmitted and is...

With growing awareness of sustainable construction, use of rammed earth and study of its mechanical parameters are proven vital. Rammed earth behaviour under lateral load and shear strength parameters plays an important role in protecting and designing new structures. Considering shear strength as a vital parameter, this paper introduces an experim...

The acoustical characteristics for building insulation of five largely available plant particles (hemp shiv, sunflower bark and pith, flax shiv and rape straw) without binder were investigated. Results show that they can all be used for acoustical absorption. Measurements were then analyzed to estimate not only the sound absorption coefficient, but...

Available throughout the world and used in construction for thousand years, earthen materials are known to improve indoor air quality while keeping the internal temperature relatively stable. In Rhône-Alpes, France, the rammed earth technic is the most spread and consists in compacting layers of earth, one by one, within a framework. Current therma...

Resumo: Verifica-se um crescimento no interesse do uso de materiais de construção amigos do ambiente, tais como o betão de cânhamo, devido à necessidade de minimizar o impacto ambiental do sector da construção nas mudanças climáticas. O betão de cânhamo possui reduzida energia incorporada durante o processo de fabrico devido à sua composição: eleva...

The essential ideas and equations of classic plasticity and hyperplasticity are successively recalled and compared, in order to highlight their differences and complementarities. The former is based on the mathematical framework proposed by Hill (The mathematical theory of plasticity. Oxford University Press, Oxford, 1950), whereas the latter is fo...

Earthen buildings can provide an answer to face difficulties in modern constructions in both terms of sociology, economics as well as ecology. However, the difficulty to understand and to predict their long term behavior represents an obstacle to their spreading. In some cases for example, unsuitable repairs on old constructions can lead to catastr...