Enrico Fodde

Hygrothermal Performance of an Experimental Hemp-Lime Building

The use of hemp-lime as a construction technique is a novel approach which combines renewable low carbon materials with exceptional hygrothermal performance. The hemp plant can grow up to 4m over a four month period, with a low fertilizer and irrigation demand, making it very efficient in the use of time and material resources. All parts of the plant can be used the seed for food stuffs, the fibre surrounding the stem for paper, clothing and resin reinforcement, and the woody core of the stem as animal bedding and aggregate in hemp-lime construction. The unique pore structure of the woody core (shiv) confers low thermal conductivity and thermal and hygric buffering to hemp-lime. The construction technique promotes good air tightness and minimal thermal bridging within the building envelope. All these factors combine to produce low carbon, hygrothermally efficient buildings which are low energy both in construction and in use, and offer opportunities for recycling at end of life. This paper reports on the hygrothermal performance of an experimental hemp-lime building, and on the development of a computerized environmental model which takes account of the phase change effects seen in hemp-lime.

Traditional Earthen Building Techniques in Central Asia

This article provides an overview of the principal earthen building materials of Central Asia and the cultural aspects of a traditional architecture that incorporates an understanding daring back centuries. The work was started by focusing on sets of research questions, which also helped to structure the study: What are the manufacturing processes of materials in the area? Based on the analysis of materials, what suggestions can be made for a more appropriate conservation of the Central Asian built heritage? There is at present a large lacuna in the literature on Central Asian materials. The traditional processes of production and the traditional methods for repairing require proper documentation. The author interviewed several craftsmen to collect data on the traditional process of manufacturing earthen materials. The aim of interviewing local craftsmen through semi-structured interviews was to increase the scant information about the local, traditional techniques of construction and the materials employed.

Conservation and conflict in the central Asian silk roads

Abstract The aim of this paper is to give a description of recent trends in heritage management and conservation in central Asia. Five countries, which became independent from the USSR in 1991, are considered: Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan and Turkmenistan. This relatively little-known region provides scope for analysing diverse approaches to philosophical and ethical conservation issues. Three case studies are described: the Bibi Khanum Mosque (Samarkand, Uzbekistan), the Aisha Bibi Mausoleum (Taraz, Kazakhstan) and the Burana Minaret (Kyrgyzstan). Several projects in the area were carried out by UNESCO with the financial support of the Japanese Funds-in-Trust for the Preservation of World Cultural Heritage. The final section of this paper is a synthesis of the pioneering role of UNESCO in implementing conservation projects, assisting the central Asian countries in the management, preservation and conservation of cultural heritage through the provision of training to national experts and craftsmen.

Conserving sites on the Central Asian Silk Roads: the case of Otrar Tobe, Kazakhstan

Abstract Conservation activities have been carried out during the four years of the UNESCO project for the Preservation and Restoration of the Ancient City of Otrar, an archaeological site located in a loess clay area in southwest Kazakhstan at the confluence of Syr Darya and Arys rivers. The paper focuses on certain conservation activities carried out at the site, including documentation of observed deterioration phenomena, authentication of surviving mudbrick and fired brick structures, and the repair of structures using an earth-based repair mortar specially developed for the site. The paper summarises the main achievements of the project in terms of conservation, documentation, training, promotional activities and master plan preparation.

Fired Brick and Sulphate Attack: The Case of Moenjodaro, Pakistan

Abstract The aim of this paper is to provide an overview of the principal causes of the failure and decay of the archaeological structures of Moenjodaro, a World Heritage Site in Pakistan, and of the low-cost measures adopted for the conservation of its 52 km of exposed walls. Improper past conservation measures and their effects on brick decay were surveyed and highlighted in the context of salts attack. In order to further understand the influence of environmental salts on the durability of fired brick and soil (mud mortar, mud brick capping), an overview of the employment of mud slurry and of poulticing is also provided.

Analytical Methods for the Conservation of the Buddhist Temple II of Krasnaya Rechka, Kyrgyzstan

Abstract The methods employed for selecting the repair material for the Buddhist temple II of Krasnaya Rechka, a site located in the upper Chuy Valley, Kyrgyzstan, are described in this article. The temple is built of mud brick and was excavated during several campaigns between 1938 and 1998 with no provision being made for conservation. The first emergency protective measures were initiated in 2003 during a UNESCO project that included other sites located in the Chuy valley. Most of the eroded walls of the temple were given a temporary shelter coat of mud bricks, a method that has proved effective. The main problem after proving the shelter coat was how to assess the repair material for future conservation work (it is planned to repeat the application of the shelter coat, but with materials with improved performance). Assessment was carried out after extensive laboratory analysis of both historic and repair materials, but also after test wall construction and monitoring. The methods explained here could be of use to conservators working in similar projects in the Middle East or Asia.

Moenjodaro: A World Heritage Site at Risk

Abstract The aim of this article is to describe the main threats affecting Moenjodaro, an archaeological site that prospered from 2350 to 1800 BC in the fertile Indus flood plain of Sindh (Pakistan). The major hazard is today represente d by soluble salts attack (mainly sodium sulphate), rising damp, heavy precipitation in the monsoon season, poor drainage, thermal stress causing walls to lean and decay structurally, visitor behaviour, site mismanagement, and the lack of vegetation. As a result of poor conservation and bad management, in the year 2000 the site was inscribed in the ICOMOS register of heritage at risk. The article analyses past and present conservation methods, and provides recommendations for future repair and maintenance.

The influence of soluble salts on the decay of Moenjodaro, Pakistan

Purpose – The World Heritage site of Moenjodaro, located in the Indus flood plain and dating to the early Bronze Age, is believed to be the most important urban centre of the Indus valley culture. The purpose of the paper is to discuss the main conservation threats and the mechanisms of decay affecting the site and to understand the influence of soluble salts on materials such as fired brick and soil. Furthermore, the paper aims to describe the repair methods employed against salt attack and provides a scheme for site management.Design/methodology/approach – In the paper a literature review is followed by laboratory experiments.Findings – The main result is the experimental assessment of the repair materials and methods traditionally employed in Moenjodaro. No evaluation was undertaken prior to this study and this makes the work the more relevant.Research limitations/implications – A more complete and detailed study of the materials examined here might have been achieved if more samples had been analysed....

Measuring evaporation distribution of mud brick and rammed earth

Purpose – Salt weathering is one of the most common agents of decay of Central Asian earthen sites and is in function of water evaporation from the wall surface. Soon after excavation the earthen walls and the stupa of the Buddhist temple of Ajina Tepa (seventh-eighth century AD) started to deteriorate due lack of protection and surface erosion. The most important issue in the planning of conservation work was to understand such mechanisms and to decrease the effect of salt weathering on structural damage. The purpose of this paper is to discuss these issues. Design/methodology/approach – Evaporation distribution and salts types were studied on selected walls. In addition, three-dimensional recording of the walls and the stupa was undertaken with digital photogrammetric methods. Findings – It was clearly found that the intensity of salt weathering in the site is high and some salts such as halite (sodium chloride) are thought to originate from groundwater. On the basis of the results obtained, thick shelt...

Structural consolidation of mud brick masonry

The first aim of this paper is to provide an illustration of fabric survey, damage assessment, and structural consolidation of the mud brick structures of Al Ain, an oasis in the United Arab Emirates. The buildings mostly date to the turn of the last century and it was concluded that damage of such vernacular architecture is represented by thermal movement, structural cracks, leaning walls, granular disintegration, erosion and creation of preferential channels, and coving. Furthermore, damage caused by animals and by recent interventions was also surveyed. The second aim of the paper is to illustrate the structural consolidation of mud brick masonry by explaining the work undertaken in the mosque of Al Jahili (1891–1898). This includes eroded wall repair, window filling, repair of cracks with the stitching technique, wall top consolidation, and roof repair.