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Earth, as a building material, has been used since ancient times, and is still being used with that purpose. It was used for building shelters, houses, temples and even military constructions, like fortresses. As a consequence, currently, there is a great architectural heritage stock on this kind of constructions. Nevertheless, earthen materials are very sensitive when compared with modern materials, since they are more vulnerable to external aggressive agents, revealing most of the times a faster degradation rate. From a structural perspective they present a very low tensile strength, a low compressive strength and a fragile behaviour, making the earthen structures strongly vulnerable to earthquakes. The structural damage in this kind of structures manifests, in general, in the form of cracks or voids. Repairing these cracks is fundamental in order to obtain an improved structural behaviour, especially if the earth construction was built in a seismic zone. Injecting mud grouts may constitute a feasible and reliable solution for repair this kind of damage. Although, mud grouts experience many problems that hinder their application and the knowledge about them is still very limited. This requires that deep studies have to be carried out in order to solve their problems and to make this solution reliable. In this paper it is discussed the methodology that should be established for the design of mud grouts suitable for earth constructions. But first a summarized explanation about earth constructions and their problems is presented. This results from an ongoing PhD research that still is in an initial phase, and it aims, precisely, the development of grouts specifically to be applied in earth constructions. ; Fundação para a Ciência e a Tecnologia ...

Buildings account for approximately one third of the total worldwide energy emissions, of which approximately a quarter can be attributed to the embodied energy of the building. Current UK legislation for low-energy homes is only concerned with operational energy. Embodied energy, and carbon, is not currently considered but over the design life of an average building is expected to make a significant contribution to the total whole life energy used. Earthen building materials contribute to reduce energy consumption in use through their passive regulation of temperature and humidity. In addition, there can also be significant embodied energy savings compared to other materials. Traditional methods of earthen construction, using locally sourced materials and manual labour require minimal energy for the transport and construction. A greater uptake of earth construction is likely to come from modern innovations such as industrialised manufacture. Extruded fired brick manufacturing processes has the potential to produce a high quality, low cost and low energy product suitable for the mainstream construction sector in both developed and developing nations. By not firing the extruded clay bricks, an embodied energy saving of 86% can be achieved, compared to fired clay, and 25% compared to concrete blocks. However, there are limitations to the structural use of unstabilised earth bricks due to the loss of strength under high moisture content conditions. The use of traditional and novel stabilisation methods can be adopted to address the concerns over strength and durability. Cement and lime are widely used in some countries, but both significantly increase material embodied energy and carbon and can inhibit passive humidity regulation. The paper presents results from a study of the embodied energy of various stabilisers used for unfired clay materials. The Global Warming Potential (GWP) is a measure of the equivalent carbon dioxide that allows for the relative weightings of damaging greenhouse gasses. Both the embodied energy and the GWP figures of various stabilisers are compared and discussed. The conclusion of the work is that there is a maximum quantity of stabiliser than should be used. Typically the quantities of stabiliser are quoted as the amount that gives the maximum strength, but this should take account of not only strength but the environmental impact of achieving the improvement.

In Nigeria and other developing countries where reinforced concrete in construction is widely used, the high and steadily increasing cost of steel has made construction very expensive. This, coupled with the political will, usually christened "Nigerian Factor" has made any conceived affordable mass housing program by successive governments a mirage. This development has triggered off the search for alternative and suitable replacement for steel reinforcement in concrete works. This search for a cheaper alternative has led to the exploration of abundant, naturally occurring materials such as bamboo, coconut fibres, sisal and oil palm fibres which can be obtained locally at low cost and low levels of energy using local manpower and technology. The use of these locally available materials as substitute for the conventional materials in reinforced concrete elements can cut construction costs by as much as between 30% and 80%. Interest in these local materials is heightened by the facts that not only are they considered cheap; they are also "eco-friendly". Also, the rising level of pollution in the construction industry has called for the adoption of "Eco-structures", which are constructions that are in harmony with the surroundings and do not violate the environment neither through the chosen building materials nor through the construction methods. Several studies have shown that contemporary earth construction has the potentials to address the urban housing crisis in the developing countries. On the other hand there is a wrong perception among the users and the professionals that, 'earth houses are only used by the poor people'. This paper investigates the information available on bamboo and earth material and their possible use as a low cost sustainable building material in Nigeria in the light of problem of affordable structure. The findings of this paper shows that more research has to be done to come up with reasonable conclusion. It has however been found that this materials has been used to carryout some of the building activities. Finally the author thinks that if more information is found more can be done to put this materials to use

The development of green building contributes to the legitimation of the use of construction materials that can take part in the fight against climate change. Among these materials, raw earth remains little invested in comparison with bio-based materials such as wood or straw. While the use of land was historically widespread in France, the construction processes incumbent on it (cob, rammed earth, mud, adobe) were removed during the 19th and 20th centuries. However, for about five decades, a field of earthen construction has been involved in promoting this material. In this research, it's about to show how the field of earthen construction has taken shape and what form it has taken by analyzing the historically variable forms of interest for earthen construction that the field requires and that the agents invest, that is to dialectize the history of the field and the incorporated social history of the agents who invest themselves in maintaining and updating the reified social history of earthen construction. This also makes it possible to analyze the social conditions of possibility of a development of earthen construction in France, in particular to measure the social conditions of possibility of a transformation of conventional construction to participate in a transformation of the social world favorable to the fight against climate change. This thesis is based on different empirical materials (interviews, archives, ethnographic observations, statistics) and mobilizes the sociology of fields to analyze the objective relationships between the fields and the agents involved in the field of earthen construction, which vary according to internal and external struggles in the field, in particular through public action which participates to define its autonomy and its relations of subordination. This research hypothesizes that the field of earthen construction is a field of forces which is at the base of economic and political struggles to maintain or transform it, in particular by orienting public action, so that ...

The development of green building contributes to the legitimation of the use of construction materials that can take part in the fight against climate change. Among these materials, raw earth remains little invested in comparison with bio-based materials such as wood or straw. While the use of land was historically widespread in France, the construction processes incumbent on it (cob, rammed earth, mud, adobe) were removed during the 19th and 20th centuries. However, for about five decades, a field of earthen construction has been involved in promoting this material. In this research, it's about to show how the field of earthen construction has taken shape and what form it has taken by analyzing the historically variable forms of interest for earthen construction that the field requires and that the agents invest, that is to dialectize the history of the field and the incorporated social history of the agents who invest themselves in maintaining and updating the reified social history of earthen construction. This also makes it possible to analyze the social conditions of possibility of a development of earthen construction in France, in particular to measure the social conditions of possibility of a transformation of conventional construction to participate in a transformation of the social world favorable to the fight against climate change. This thesis is based on different empirical materials (interviews, archives, ethnographic observations, statistics) and mobilizes the sociology of fields to analyze the objective relationships between the fields and the agents involved in the field of earthen construction, which vary according to internal and external struggles in the field, in particular through public action which participates to define its autonomy and its relations of subordination. This research hypothesizes that the field of earthen construction is a field of forces which is at the base of economic and political struggles to maintain or transform it, in particular by orienting public action, so that ...

The development of green building contributes to the legitimation of the use of construction materials that can take part in the fight against climate change. Among these materials, raw earth remains little invested in comparison with bio-based materials such as wood or straw. While the use of land was historically widespread in France, the construction processes incumbent on it (cob, rammed earth, mud, adobe) were removed during the 19th and 20th centuries. However, for about five decades, a field of earthen construction has been involved in promoting this material. In this research, it's about to show how the field of earthen construction has taken shape and what form it has taken by analyzing the historically variable forms of interest for earthen construction that the field requires and that the agents invest, that is to dialectize the history of the field and the incorporated social history of the agents who invest themselves in maintaining and updating the reified social history of earthen construction. This also makes it possible to analyze the social conditions of possibility of a development of earthen construction in France, in particular to measure the social conditions of possibility of a transformation of conventional construction to participate in a transformation of the social world favorable to the fight against climate change. This thesis is based on different empirical materials (interviews, archives, ethnographic observations, statistics) and mobilizes the sociology of fields to analyze the objective relationships between the fields and the agents involved in the field of earthen construction, which vary according to internal and external struggles in the field, in particular through public action which participates to define its autonomy and its relations of subordination. This research hypothesizes that the field of earthen construction is a field of forces which is at the base of economic and political struggles to maintain or transform it, in particular by orienting public action, so that the agents who are there committed can, according to what is in their power, actualize or create the most favorable conditions for their accomplishment, that is to say for the adjustment of their dispositions to their conditions of existence. The first part of the thesis is interested in the genesis of the field of earthen construction by showing how, from the emergence to the social dissolution of the cob in the Breton rural space and the rammed earth in the urban space of Lyon, earthen construction was reinvested nationally from the 1970s and led to the autonomy of the field in the 1980s. The second part attempts to describe the economic activity of earthen construction. The focus is, on the one hand, in the structure of earth construction professionals and their economic strategies and, on the other hand, in socially characterizing the agents who live in a earthen house built in recent decades through their social position, their residential trajectory and the residential strategies they implement. The third part focuses more particularly on the political struggle of the agents engaged in the field to maintain or transform its principle of vision. By approaching the institutionalization of ecological construction as a category of public action, it's about of studying the appropriation of this category by the agents through the struggle they lead to make see and assert their principle of vision within the field. ; Le développement de la construction écologique participe à la légitimation de l'emploi des matériaux de construction pouvant alimenter la lutte contre le changement climatique. Parmi ces matériaux, la terre crue demeure peu investie en comparaison de matériaux biosourcés tels que le bois ou la paille. Alors que l'emploi de la terre était historiquement répandu en France, les procédés de construction qui lui incombent (bauge, pisé, torchis, adobe) ont été destitués au cours des XIXème et XXème siècles. Pourtant, depuis environ cinq décennies, un champ de la construction en terre participe à faire la promotion de ce matériau. Dans cette recherche, il s'agit de montrer comment le champ de la construction en terre a pris forme et quelle forme il a prise en analysant les formes d'intérêt historiquement variables pour la construction en terre qu'exige le champ et qu'engagent les agents, c'est-à-dire de dialectiser l'histoire du champ et l'histoire sociale incorporée des agents qui s'investissent pour entretenir et actualiser l'histoire sociale réifiée de la construction en terre crue. Cela permet aussi d'analyser les conditions sociales de possibilité d'un développement de la construction en terre crue en France, notamment pour mesurer les conditions sociales de possibilité d'une transformation de la construction conventionnelle pour participer à une transformation du monde social favorable à la lutte contre le changement climatique. Cette thèse s'appuie sur différents matériaux empiriques (entretiens, archives, observations ethnographiques, statistiques) et mobilise la sociologie des champs pour analyser les relations objectives entre les champs et les agents engagés dans le champ de la construction en terre crue, qui varient selon les luttes internes et externes au champ, notamment par l'action publique qui contribue à définir son autonomie et ses rapports de subordination. Cette recherche fait l'hypothèse que le champ de la construction en terre est un champ de forces qui est au principe de luttes économique et politique pour le maintenir ou le transformer, notamment en orientant l'action publique, afin que les agents qui y sont engagés puissent, selon ce qui est en leur pouvoir, actualiser ou créer les conditions les plus favorables à leur accomplissement, c'est-à-dire à l'ajustement de leurs dispositions à leurs conditions d'existence. La première partie de la thèse aborde la genèse du champ de la construction en terre crue en montrant comment, de l'émergence à la dissolution sociale de la bauge dans l'espace rural breton et du pisé de terre dans l'espace urbain lyonnais, la construction en terre est réinvestie à l'échelle nationale à partir des années 1970 et conduit à l'autonomisation du champ au cours des années 1980. La deuxième partie s'attache à décrire l'activité économique de la construction en terre. Il s'agit de s'intéresser, d'une part, à la structure des professionnels de la construction en terre et à leur prise de position économique et, d'autre part, à caractériser socialement les particuliers qui habitent dans une maison en terre construite ces dernières décennies à travers leur position sociale, leur trajectoire résidentielle et les stratégies résidentielles qu'ils mettent en œuvre. La troisième partie s'attache plus particulièrement à la lutte politique des agents engagés dans le champ pour maintenir ou transformer son principe de vision. En abordant l'institutionnalisation de la construction écologique comme catégorie de l'action publique, il s'agit d'étudier l'appropriation de cette catégorie par les agents à travers la lutte qu'ils mènent pour faire voir et valoir leur principe de vision au sein du champ.

The development of green building contributes to the legitimation of the use of construction materials that can take part in the fight against climate change. Among these materials, raw earth remains little invested in comparison with bio-based materials such as wood or straw. While the use of land was historically widespread in France, the construction processes incumbent on it (cob, rammed earth, mud, adobe) were removed during the 19th and 20th centuries. However, for about five decades, a field of earthen construction has been involved in promoting this material. In this research, it's about to show how the field of earthen construction has taken shape and what form it has taken by analyzing the historically variable forms of interest for earthen construction that the field requires and that the agents invest, that is to dialectize the history of the field and the incorporated social history of the agents who invest themselves in maintaining and updating the reified social history of earthen construction. This also makes it possible to analyze the social conditions of possibility of a development of earthen construction in France, in particular to measure the social conditions of possibility of a transformation of conventional construction to participate in a transformation of the social world favorable to the fight against climate change. This thesis is based on different empirical materials (interviews, archives, ethnographic observations, statistics) and mobilizes the sociology of fields to analyze the objective relationships between the fields and the agents involved in the field of earthen construction, which vary according to internal and external struggles in the field, in particular through public action which participates to define its autonomy and its relations of subordination. This research hypothesizes that the field of earthen construction is a field of forces which is at the base of economic and political struggles to maintain or transform it, in particular by orienting public action, so that the agents who are there committed can, according to what is in their power, actualize or create the most favorable conditions for their accomplishment, that is to say for the adjustment of their dispositions to their conditions of existence. The first part of the thesis is interested in the genesis of the field of earthen construction by showing how, from the emergence to the social dissolution of the cob in the Breton rural space and the rammed earth in the urban space of Lyon, earthen construction was reinvested nationally from the 1970s and led to the autonomy of the field in the 1980s. The second part attempts to describe the economic activity of earthen construction. The focus is, on the one hand, in the structure of earth construction professionals and their economic strategies and, on the other hand, in socially characterizing the agents who live in a earthen house built in recent decades through their social position, their residential trajectory and the residential strategies they implement. The third part focuses more particularly on the political struggle of the agents engaged in the field to maintain or transform its principle of vision. By approaching the institutionalization of ecological construction as a category of public action, it's about of studying the appropriation of this category by the agents through the struggle they lead to make see and assert their principle of vision within the field. ; Le développement de la construction écologique participe à la légitimation de l'emploi des matériaux de construction pouvant alimenter la lutte contre le changement climatique. Parmi ces matériaux, la terre crue demeure peu investie en comparaison de matériaux biosourcés tels que le bois ou la paille. Alors que l'emploi de la terre était historiquement répandu en France, les procédés de construction qui lui incombent (bauge, pisé, torchis, adobe) ont été destitués au cours des XIXème et XXème siècles. Pourtant, depuis environ cinq décennies, un champ de la construction en terre participe à faire la promotion de ce matériau. Dans cette recherche, il s'agit de montrer comment le champ de la construction en terre a pris forme et quelle forme il a prise en analysant les formes d'intérêt historiquement variables pour la construction en terre qu'exige le champ et qu'engagent les agents, c'est-à-dire de dialectiser l'histoire du champ et l'histoire sociale incorporée des agents qui s'investissent pour entretenir et actualiser l'histoire sociale réifiée de la construction en terre crue. Cela permet aussi d'analyser les conditions sociales de possibilité d'un développement de la construction en terre crue en France, notamment pour mesurer les conditions sociales de possibilité d'une transformation de la construction conventionnelle pour participer à une transformation du monde social favorable à la lutte contre le changement climatique. Cette thèse s'appuie sur différents matériaux empiriques (entretiens, archives, observations ethnographiques, statistiques) et mobilise la sociologie des champs pour analyser les relations objectives entre les champs et les agents engagés dans le champ de la construction en terre crue, qui varient selon les luttes internes et externes au champ, notamment par l'action publique qui contribue à définir son autonomie et ses rapports de subordination. Cette recherche fait l'hypothèse que le champ de la construction en terre est un champ de forces qui est au principe de luttes économique et politique pour le maintenir ou le transformer, notamment en orientant l'action publique, afin que les agents qui y sont engagés puissent, selon ce qui est en leur pouvoir, actualiser ou créer les conditions les plus favorables à leur accomplissement, c'est-à-dire à l'ajustement de leurs dispositions à leurs conditions d'existence. La première partie de la thèse aborde la genèse du champ de la construction en terre crue en montrant comment, de l'émergence à la dissolution sociale de la bauge dans l'espace rural breton et du pisé de terre dans l'espace urbain lyonnais, la construction en terre est réinvestie à l'échelle nationale à partir des années 1970 et conduit à l'autonomisation du champ au cours des années 1980. La deuxième partie s'attache à décrire l'activité économique de la construction en terre. Il s'agit de s'intéresser, d'une part, à la structure des professionnels de la construction en terre et à leur prise de position économique et, d'autre part, à caractériser socialement les particuliers qui habitent dans une maison en terre construite ces dernières décennies à travers leur position sociale, leur trajectoire résidentielle et les stratégies résidentielles qu'ils mettent en œuvre. La troisième partie s'attache plus particulièrement à la lutte politique des agents engagés dans le champ pour maintenir ou transformer son principe de vision. En abordant l'institutionnalisation de la construction écologique comme catégorie de l'action publique, il s'agit d'étudier l'appropriation de cette catégorie par les agents à travers la lutte qu'ils mènent pour faire voir et valoir leur principe de vision au sein du champ.

The development of green building contributes to the legitimation of the use of construction materials that can take part in the fight against climate change. Among these materials, raw earth remains little invested in comparison with bio-based materials such as wood or straw. While the use of land was historically widespread in France, the construction processes incumbent on it (cob, rammed earth, mud, adobe) were removed during the 19th and 20th centuries. However, for about five decades, a field of earthen construction has been involved in promoting this material. In this research, it's about to show how the field of earthen construction has taken shape and what form it has taken by analyzing the historically variable forms of interest for earthen construction that the field requires and that the agents invest, that is to dialectize the history of the field and the incorporated social history of the agents who invest themselves in maintaining and updating the reified social history of earthen construction. This also makes it possible to analyze the social conditions of possibility of a development of earthen construction in France, in particular to measure the social conditions of possibility of a transformation of conventional construction to participate in a transformation of the social world favorable to the fight against climate change. This thesis is based on different empirical materials (interviews, archives, ethnographic observations, statistics) and mobilizes the sociology of fields to analyze the objective relationships between the fields and the agents involved in the field of earthen construction, which vary according to internal and external struggles in the field, in particular through public action which participates to define its autonomy and its relations of subordination. This research hypothesizes that the field of earthen construction is a field of forces which is at the base of economic and political struggles to maintain or transform it, in particular by orienting public action, so that the agents who are there committed can, according to what is in their power, actualize or create the most favorable conditions for their accomplishment, that is to say for the adjustment of their dispositions to their conditions of existence. The first part of the thesis is interested in the genesis of the field of earthen construction by showing how, from the emergence to the social dissolution of the cob in the Breton rural space and the rammed earth in the urban space of Lyon, earthen construction was reinvested nationally from the 1970s and led to the autonomy of the field in the 1980s. The second part attempts to describe the economic activity of earthen construction. The focus is, on the one hand, in the structure of earth construction professionals and their economic strategies and, on the other hand, in socially characterizing the agents who live in a earthen house built in recent decades through their social position, their residential trajectory and the residential strategies they implement. The third part focuses more particularly on the political struggle of the agents engaged in the field to maintain or transform its principle of vision. By approaching the institutionalization of ecological construction as a category of public action, it's about of studying the appropriation of this category by the agents through the struggle they lead to make see and assert their principle of vision within the field. ; Le développement de la construction écologique participe à la légitimation de l'emploi des matériaux de construction pouvant alimenter la lutte contre le changement climatique. Parmi ces matériaux, la terre crue demeure peu investie en comparaison de matériaux biosourcés tels que le bois ou la paille. Alors que l'emploi de la terre était historiquement répandu en France, les procédés de construction qui lui incombent (bauge, pisé, torchis, adobe) ont été destitués au cours des XIXème et XXème siècles. Pourtant, depuis environ cinq décennies, un champ de la construction en terre participe à faire la promotion de ce matériau. Dans cette recherche, il s'agit de montrer comment le champ de la construction en terre a pris forme et quelle forme il a prise en analysant les formes d'intérêt historiquement variables pour la construction en terre qu'exige le champ et qu'engagent les agents, c'est-à-dire de dialectiser l'histoire du champ et l'histoire sociale incorporée des agents qui s'investissent pour entretenir et actualiser l'histoire sociale réifiée de la construction en terre crue. Cela permet aussi d'analyser les conditions sociales de possibilité d'un développement de la construction en terre crue en France, notamment pour mesurer les conditions sociales de possibilité d'une transformation de la construction conventionnelle pour participer à une transformation du monde social favorable à la lutte contre le changement climatique. Cette thèse s'appuie sur différents matériaux empiriques (entretiens, archives, observations ethnographiques, statistiques) et mobilise la sociologie des champs pour analyser les relations objectives entre les champs et les agents engagés dans le champ de la construction en terre crue, qui varient selon les luttes internes et externes au champ, notamment par l'action publique qui contribue à définir son autonomie et ses rapports de subordination. Cette recherche fait l'hypothèse que le champ de la construction en terre est un champ de forces qui est au principe de luttes économique et politique pour le maintenir ou le transformer, notamment en orientant l'action publique, afin que les agents qui y sont engagés puissent, selon ce qui est en leur pouvoir, actualiser ou créer les conditions les plus favorables à leur accomplissement, c'est-à-dire à l'ajustement de leurs dispositions à leurs conditions d'existence. La première partie de la thèse aborde la genèse du champ de la construction en terre crue en montrant comment, de l'émergence à la dissolution sociale de la bauge dans l'espace rural breton et du pisé de terre dans l'espace urbain lyonnais, la construction en terre est réinvestie à l'échelle nationale à partir des années 1970 et conduit à l'autonomisation du champ au cours des années 1980. La deuxième partie s'attache à décrire l'activité économique de la construction en terre. Il s'agit de s'intéresser, d'une part, à la structure des professionnels de la construction en terre et à leur prise de position économique et, d'autre part, à caractériser socialement les particuliers qui habitent dans une maison en terre construite ces dernières décennies à travers leur position sociale, leur trajectoire résidentielle et les stratégies résidentielles qu'ils mettent en œuvre. La troisième partie s'attache plus particulièrement à la lutte politique des agents engagés dans le champ pour maintenir ou transformer son principe de vision. En abordant l'institutionnalisation de la construction écologique comme catégorie de l'action publique, il s'agit d'étudier l'appropriation de cette catégorie par les agents à travers la lutte qu'ils mènent pour faire voir et valoir leur principe de vision au sein du champ.

The development of green building contributes to the legitimation of the use of construction materials that can take part in the fight against climate change. Among these materials, raw earth remains little invested in comparison with bio-based materials such as wood or straw. While the use of land was historically widespread in France, the construction processes incumbent on it (cob, rammed earth, mud, adobe) were removed during the 19th and 20th centuries. However, for about five decades, a field of earthen construction has been involved in promoting this material. In this research, it's about to show how the field of earthen construction has taken shape and what form it has taken by analyzing the historically variable forms of interest for earthen construction that the field requires and that the agents invest, that is to dialectize the history of the field and the incorporated social history of the agents who invest themselves in maintaining and updating the reified social history of earthen construction. This also makes it possible to analyze the social conditions of possibility of a development of earthen construction in France, in particular to measure the social conditions of possibility of a transformation of conventional construction to participate in a transformation of the social world favorable to the fight against climate change. This thesis is based on different empirical materials (interviews, archives, ethnographic observations, statistics) and mobilizes the sociology of fields to analyze the objective relationships between the fields and the agents involved in the field of earthen construction, which vary according to internal and external struggles in the field, in particular through public action which participates to define its autonomy and its relations of subordination. This research hypothesizes that the field of earthen construction is a field of forces which is at the base of economic and political struggles to maintain or transform it, in particular by orienting public action, so that the agents who are there committed can, according to what is in their power, actualize or create the most favorable conditions for their accomplishment, that is to say for the adjustment of their dispositions to their conditions of existence. The first part of the thesis is interested in the genesis of the field of earthen construction by showing how, from the emergence to the social dissolution of the cob in the Breton rural space and the rammed earth in the urban space of Lyon, earthen construction was reinvested nationally from the 1970s and led to the autonomy of the field in the 1980s. The second part attempts to describe the economic activity of earthen construction. The focus is, on the one hand, in the structure of earth construction professionals and their economic strategies and, on the other hand, in socially characterizing the agents who live in a earthen house built in recent decades through their social position, their residential trajectory and the residential strategies they implement. The third part focuses more particularly on the political struggle of the agents engaged in the field to maintain or transform its principle of vision. By approaching the institutionalization of ecological construction as a category of public action, it's about of studying the appropriation of this category by the agents through the struggle they lead to make see and assert their principle of vision within the field. ; Le développement de la construction écologique participe à la légitimation de l'emploi des matériaux de construction pouvant alimenter la lutte contre le changement climatique. Parmi ces matériaux, la terre crue demeure peu investie en comparaison de matériaux biosourcés tels que le bois ou la paille. Alors que l'emploi de la terre était historiquement répandu en France, les procédés de construction qui lui incombent (bauge, pisé, torchis, adobe) ont été destitués au cours des XIXème et XXème siècles. Pourtant, depuis environ cinq décennies, un champ de la construction en terre participe à faire la promotion de ce matériau. Dans cette recherche, il s'agit de montrer comment le champ de la construction en terre a pris forme et quelle forme il a prise en analysant les formes d'intérêt historiquement variables pour la construction en terre qu'exige le champ et qu'engagent les agents, c'est-à-dire de dialectiser l'histoire du champ et l'histoire sociale incorporée des agents qui s'investissent pour entretenir et actualiser l'histoire sociale réifiée de la construction en terre crue. Cela permet aussi d'analyser les conditions sociales de possibilité d'un développement de la construction en terre crue en France, notamment pour mesurer les conditions sociales de possibilité d'une transformation de la construction conventionnelle pour participer à une transformation du monde social favorable à la lutte contre le changement climatique. Cette thèse s'appuie sur différents matériaux empiriques (entretiens, archives, observations ethnographiques, statistiques) et mobilise la sociologie des champs pour analyser les relations objectives entre les champs et les agents engagés dans le champ de la construction en terre crue, qui varient selon les luttes internes et externes au champ, notamment par l'action publique qui contribue à définir son autonomie et ses rapports de subordination. Cette recherche fait l'hypothèse que le champ de la construction en terre est un champ de forces qui est au principe de luttes économique et politique pour le maintenir ou le transformer, notamment en orientant l'action publique, afin que les agents qui y sont engagés puissent, selon ce qui est en leur pouvoir, actualiser ou créer les conditions les plus favorables à leur accomplissement, c'est-à-dire à l'ajustement de leurs dispositions à leurs conditions d'existence. La première partie de la thèse aborde la genèse du champ de la construction en terre crue en montrant comment, de l'émergence à la dissolution sociale de la bauge dans l'espace rural breton et du pisé de terre dans l'espace urbain lyonnais, la construction en terre est réinvestie à l'échelle nationale à partir des années 1970 et conduit à l'autonomisation du champ au cours des années 1980. La deuxième partie s'attache à décrire l'activité économique de la construction en terre. Il s'agit de s'intéresser, d'une part, à la structure des professionnels de la construction en terre et à leur prise de position économique et, d'autre part, à caractériser socialement les particuliers qui habitent dans une maison en terre construite ces dernières décennies à travers leur position sociale, leur trajectoire résidentielle et les stratégies résidentielles qu'ils mettent en œuvre. La troisième partie s'attache plus particulièrement à la lutte politique des agents engagés dans le champ pour maintenir ou transformer son principe de vision. En abordant l'institutionnalisation de la construction écologique comme catégorie de l'action publique, il s'agit d'étudier l'appropriation de cette catégorie par les agents à travers la lutte qu'ils mènent pour faire voir et valoir leur principe de vision au sein du champ.

In Puerto Rico, there is evidence of two earth constructions for the 16th century. The technique used was rammed earth. This knowledge did not proliferate or evolve, in fact, today there are no modern constructions made on earth. The average of Puerto Rican does not know about earth constructions and due to this inexperience there is much skepticism about the frequency of hurricanes, high precipitation and being prone to earthquakes / tsunamis. The relevance of finding historical precedents in Puerto Rico would help to understand their behavior over time. Countless research indicates that these constructions have been effective in places with similar conditions those the island. In the era of climate change, it is important to obtain this ancestral knowledge of materials that have solved the need for housing with a low environmental impact. After the passage of the last hurricane Maria, Puerto Rico faced the reality that exists when we understand the dependence on fossil and non-renewable energy, the importation by ship of building materials and the exercise of recovering from the government (top to bottom), It is very fragile and susceptible. Through a search of the documentation in Historical Archives, it was possible to locate and obtain information on the earth construction. According to several sources of scientific research, it is possible to face environmental problems based on the knowledge that empowers from the town and with adjustments in our lifestyle, it was understood that the limitations are in the ignorance. ; En Puerto Rico existe evidencia de dos estructuras de tierra en el siglo XVI. La técnica que se utilizó fue la tapia. Este conocimiento no proliferó ni evolucionó. De hecho, hoy día no existen construcciones modernas hechas con tierra. La gente puertorriqueña promedio no conoce sobre las construcciones de tierra y debido a esa inexperiencia existe mucho escepticismo por la frecuencia de huracanes, la alta precipitación y la propensión a terremotos y maremotos. La pertinencia de encontrar precedentes históricos en Puerto Rico ayuda a entender el comportamiento de éstas a través del tiempo. Un sinnúmero de investigaciones apunta a que estas construcciones han sido efectivas en lugares con condiciones similares a las de la isla. En plena era del cambio climático es importante obtener conocimiento ancestral de materiales que han resuelto la necesidad de vivienda con un bajo impacto ambiental. Luego del paso del último huracán –María–, se enfrentó la realidad que existe cuando entendemos que la dependencia de la energía fósil y no renovable, la importación de los materiales de construcción por barco y el ejercicio de recuperarnos desde el gobierno (desde arriba), es muy frágil y susceptible. A través de una búsqueda de documentación en archivos históricos se pudo llegar a localizar y obtener información sobre la construcción con tierra. Según varias investigaciones científicas es posible enfrentar problemas ambientales a través de saberes que empoderan desde el pueblo y con ajustes en nuestro estilo de vida para entender así que las limitaciones se encuentran en el desconocimiento.