Análisis comparativo de las intervenciones en fábricas de tapial. El caso de las fortificaciones

A pesar del gran número de monumentos históricos de tierra dañados, se conoce poco acerca de cómo reparar las fisuras que se producen en sus muros estructurales. En muchos casos, las paredes de adobe sufren una disminución significativa de su resistencia y rigidez, que podría conducir a la pérdida de estabilidad y al colapso. Es importante, por lo tanto, encontrar formas de reparar los daños en muros estructurales de monumentos de tierra, a fin de recuperar su resistencia y rigidez originales. Este artículo presenta resultados de un programa experimental realizado para estudiar la posibilidad de reparar fisuras en muros estructurales de adobe por medio de la inyección de morteros líquidos (grouts) de barro. Los grouts estudiados fueron preparados con suelo tamizado solo y también con aditivos estabilizadores como cal, cemento y yeso. Se ejecutaron ensayos de tracción indirecta (una adaptación del ensayo brasileño de tracción indirecta para cilindros de concreto) en “emparedados” de adobe para determinar la dosificación de las mezclas que proporcionen buena adherencia entre el bloque y el mortero. Para comprobar la eficiencia de la reparación con estos grouts seleccionados, se construyeron muretes de adobe de 700 x 700 mm. que fueron ensayados en compresión diagonal (ASTM) y medida su resistencia. Luego de agrietados por estos ensayos, se repararon los muretes con inyecciones de grouts de barro, y posteriormente, ensayados nuevamente para estimar la efectividad del método de reparación. En este documento, se presenta un procedimiento práctico para reparar muros de adobe agrietados, mediante inyecciones líquidas (grouts) de barro solo o con aditivos estabilizadores y explica sus fundamentos y respaldo experimental, creando un nuevo criterio de recuperación de resistencia y un nuevo criterio de intervención para la conservación monumental de arquitectura de tierra, que se ha empezado a mostrar a la comunidad mundial de conservación. En el Perú, ya se han iniciado sus aplicaciones en obras de conservació

Generación automática de distribuciones en planta: Parte II

RESUMEN Con este artículo se completa la descripción del método de generación automática de distribuciones en planta iniciado en un artículo anterior de esta misma revista. En este se exponen los algoritmos desarrollados para la generación, representación gráfica y optimización automática, de todas las soluciones de distribuciones en plantas que satisfacen las restricciones impuestas por el diseñador. SUMMARY This paper completes the description of the automatic generation layout method, which was iniciated in a paper previously published in this bulletin. We explain the algorithrns that have been developed for the generation, graphic representation and automatic optimization of the floor-plan layout satisfying the restrictions imposed by designer.Peer Reviewe

Generación automática de distribuciones en planta: Parte I

Peer Reviewe

Evaluation of vernacular earthern architecture in the province of Mendoza. Approaches and results

Objetivo El patrimonio construido en Argentina, aunque relativamente joven en términos cronológicos, es amplio y diverso. Las edificaciones vernáculas, aquellas realizadas con medios y técnicas tradicionales y estrechamente ligadas a la cultura popular y anónima, constituyen buena parte de ese patrimonio material e inmaterial, ya que se fundamentan en la propia cultura popular y en sus tradiciones constructivas. Aunque en general en Argentina todo el patrimonio edificado es vulnerable, en el caso de la provincia de Mendoza es más evidente fundamentalmente por sus condiciones ambientales. Este trabajo plantea una evaluación del patrimonio vernáculo en norte de la provincia de Mendoza, con el fin de identificar las claves de su degradación, el estado de las tradiciones constructivas y de sus perspectivas y posibilidades a futuro. Metodología Para ello se realizó un muestreo intencionado de casos en función de los contextos relevantes para la reproducción de esta arquitectura. Mediante herramientas para el relevamiento, evaluación y diagnóstico se plantea la situación actual y las posibles perspectivas. Conclusiones La evaluación de lesiones y riesgos demuestra que la supuesta debilidad de la técnica tradicional no es la causa de su degradación y que si la calidad de la construcción es adecuada el riesgo ante el sismo puede ser reducido. Sin embargo, se comprueba cómo en el ámbito urbano es donde las tradiciones constructivas corren mayor peligro fundamentalmente debido a la asociación como arquitectura pobre y a la pérdida de los oficios tradicionales. Originalidad Este artículo se inscribe en el campo interdisciplinar donde se emplean procedimientos tecnológicos y aspectos clave relacionados con las políticas de tomas de decisión en la conservación del patrimonio. Su relevancia y originalidad se sustenta en haber adoptado una perspectiva metodológica cuantitativa y cualitativa aplicada al patrimonio popular, con la finalidad de comprender sus dinámicas de cambios. Asimismo, esta investigación muestra la eficacia de las herramientas informáticas para analizar diferentes casos de estudio en ámbitos urbanos o rurales.Objective The built heritage in Argentina is wide and diverse, although relatively new in chronological terms. Vernacular buildings are made by traditional means and strongly associated to the anonymous and popular culture. They comprise a large portion of that tangible and intangible heritage since it is based on the popular culture itself and on its constructive traditions. Although the built heritage in Argentina is in general at risk, is more evident in the case of the province of Mendoza, due to its environmental conditions. This work proposes an assessment of the vernacular heritage in the north of the province of Mendoza in order to point out the keys of its deterioration, the condition of the constructive traditions and their future prospects. Methodology For that purpose, a sampling of the cases was carried out according to relevant situations where this type of architecture is prominent. The current situation and the perspectives are suggested by means of several surveying, evaluation and diagnostic tools. Conclusions Failure and risk assessment proves that the cause of the deterioration is not the assumed weakness of the traditional technique. Furthermore, the seismic risk may be low if the construction quality is adequate. It is confirmed that traditional building techniques are currently more threatened in urban areas due to their association as architecture for the poor and to the loss of traditional crafts. Originality The paper is set within a multidisciplinary field, where technological procedures and the key aspects involved in the decision-making policy in "heritage conservation" are identified. Its relevance and original contribution derives from having adopted a quantitative and qualitative methodological perspective on vernacular heritage in order to understand the dynamics of the changes. Besides that, the paper shows de efficient of the informatics tools to analyze different cases in urban and rural territories

Conservation of andalusian monumental heritage: the case study of the Niebla walls in Spain

The conservation process through interventions in a building requires adequate prior expert opinion. The diagnosis and subsequent safety assessment - raised in ICOMOS guidelines - are suitable mechanisms for the study of a heritage structure. Diagnosis involves a historical analysis of the past, as a tool to predict future responses; qualitative analysis determines the deterioration and the origin of the pathological process; and quantitative analysis characterizes components by observations and experimental measurements. However, in the short or medium term ineffective decisions might be taken if assessing the state of a building using only the aforementioned tools.The Declaration of Assisi (ISCARSAH, 2000) stresses the need for prevention and the successful management of a risk-prevention program. By completing all assessment reports, in addition to a suitable risk assessment focused on the intervention and design of appropriate preventive measures, ensures a reduction in the vulnerability of a structure by managing a significant improvement in durability and, therefore, the sustainability of conservation and maintenance processes.In order to verify such vulnerability of different degrees of interventions (comprehensive, partial, or none), the Almohad rammed earth walls of Niebla, Huelva, Spain was considered as a representative case study. It is almost 2-km long and includes 47 towers. The fortification complex currently has heterogeneous characteristics, although an almost entirely uniform appearance has been maintained. Since 1980, there have been several restorations that, from the beginning, reflect mixed results over time. Based on the results of an assessment, current circumstances and risks, a diagnosis was made in order to design and prioritize preventive and corrective measures that will permit greater durability of the walls of Niebl

Assessment of heritage rammed-earth buildings. The Alcázar of King Don Pedro I (Spain).

The conservation and maintenance of earthen buildings is crucial, especially when dealing with heritage sites. This normally involves considerable effort in preliminary studies, which must be well planned in order to efficiently manage any restoration. This case study proposes a methodology to briefly assess the current state of a historical rammed-earth wall, to bring to light specific information regarding approaches for subsequent studies or decisions. This methodology is based on the study of damage and risk as a tool to swiftly discern critical areas or issues needing immediate attention. The procedure is illustrated on an outstanding heritage building: the Alcázar of King Don Pedro I in Carmona (Seville, Spain). Our conclusions confirm that this methodology constitutes an efficient and straightforward means to obtain not only a preliminary assessment of rammed-earth walls, but also objective and useful criteria for decision-makers

Rammed Earth Construction: A Proposal for a Statistical Quality Control in the Execution Process

Unlike other common contemporary construction materials such as concrete, mortars, or fired clay bricks, which are widely supported by international standards and regulations, building with rammed earth is barely regulated. Furthermore, its quality control is usually problematic, which regularly encourages the rejection of this technique. In the literature, many authors have suggested ways to safely build a rammed earth wall, but only a few of them have delved into its quality control before and during the construction process. This paper introduces a preliminary methodology and establishes unified criteria, based in a statistical analysis, for both the production and the quality control of this constructive technique in cases dealing with both samples and walls

Considerations on the physical and mechanical properties of lime-stabilized rammed earth walls and their evaluation by ultrasonic pulse velocity testing

This study examines the influence of moulding moisture content on the compressive strength, dry density and porosity of a rammed earth wall, using ultrasound as a complementary technique. Non-parametric and multivariate statistical techniques were applied to analyse the behaviour of variables with a sufficiently large population. The statistical analysis demonstrated that excessive or insufficient moulding moisture content directly determines the physical-mechanical properties of such walls. Ultrasound was confirmed as a valid technique for assessing the quality of a wall, since its response, albeit with certain limitations, was consistent with physical-mechanical properties

Adaptive Comfort Models Applied to Existing Dwellings in Mediterranean Climate Considering Global Warming

Comfort analysis of existing naturally ventilated buildings located in mild climates, such as the ones in the Mediterranean zones, offer room for a reduction in the present and future energy consumption. Regarding Spain, most of the present building stock was built before energy standards were mandatory, let alone considerations about global warming or adaptive comfort. In this context, this research aims at assessing adaptive thermal comfort of inhabitants of extant apartments building in the South of Spain per EN 15251:2007 and ASHRAE 55-2013. The case study is statistically representative housing built in 1973. On-site monitoring of comfort conditions and computer simulations for present conditions have been carried out, clarifying the degree of adaptive comfort at present time. After that, additional simulations for 2020, 2050, and 2080 are performed to check whether this dwelling will be able to provide comfort considering a change in climate conditions. As a result, the study concludes that levels of adaptive comfort can be considered satisfactory at present time in these dwellings, but not in the future, when discomfort associated with hot conditions will be recurrent. These results provide a hint to foresee how extant dwellings, and also dwellers, should adapt to a change in environmental conditions