Thermodynamic calculations for the salt crystallisation damage in porous built heritage using PHREEQC

This work considers the crystallisation mechanisms of the most common and aggressive salts that generate stress in porous building stones as a result of changing ambient conditions. These mechanisms include the salt crystallisation that result from decreasing relative humidity and changes in temperature and, in hydrated salts, the dissolution of the lower hydrated form and the subsequent precipitation of the hydrated salt. We propose a new methodology for thermodynamic calculations using PHREEQC that includes these crystallisation mechanisms. This approach permits the calculation of the equilibrium relative humidity and the parameterization of the critical relative humidity and crystallisation pressures for the dissolution–precipitation transitions. The influence of other salts on the effectives of salt crystallisation and chemical weathering is also assessed. We review the sodium and magnesium sulphate and sodium chloride systems, in both single and multicomponent solutions, and they are compared to the sodium carbonate and calcium carbonate systems. The variation of crystallisation pressure, the formation of new minerals and the chemical dissolution by the presence of other salts is also evaluated. Results for hydrated salt systems show that high crystallisation pressures are possible as lower hydrated salts dissolve and more hydrated salts precipitate. High stresses may be also produced by decreasing temperature, although it requires that porous materials are wet for long periods of time. The presence of other salts changes the temperature and relative humidity of salt transitions that generates stress rather than reducing the pressure of crystallisation, if any salt has previously precipitated. Several practical conclusions derive from proposed methodology and provide conservators and architects with information on the potential weathering activity of soluble salts. Furthermore, the model calculations might be coupled with projections of future climate to give as improved understanding of the likely changes in the frequency of phase transitions in salts within porous stone.

The influence of rock fabric in the durability of two sandstones used in the Andalusian Architectural Heritage (Montoro and Ronda, Spain)

Natural stone has been a popular and reliable building material throughout history appearing in many historic monuments and in more recent buildings. Research into the intrinsic properties of specific stones is important because it gives us a greater understanding of the factors that limit and act on them. This can help prevent serious problems from occurring in our buildings bringing both esthetic benefits and financial savings. To this end, the main objective of this research has been to study the influence of the fabric and the mineral composition of two types of sandstone on their durability. The first is a red continental sandstone from the Buntsandstein Age called “Molinaza Roja”, which is quarried in Montoro (Cordoba). The second is quarried in Ronda (Malaga) and is sold under the trade name of “Arenisca Ronda”. It is a light pink-whitish calcarenite deposited during the Late Tortonian to Late Messinian. We characterized their petrological and petrophysical properties by studying their rock fabrics, porous systems and mechanical properties. In order to obtain a complete vision of the behavior of their rock fabrics, we also carried out two decay tests, the salt crystallization and the freeze–thaw tests. We then measured the effects on the textures of the altered samples during and after the decay tests and we evaluated the changes in the porous system. By comparing the results between intact and altered samples, we found that Arenisca Ronda is less durable because it has a high quantity of expandable clays (smectites) and a high percentage of pores in the 0.1–1 μm range, in which the pressure produced by salt crystallization is strongest. In Molinaza Roja the decay agents caused significant sanding due to loss of cohesion between the clasts, especially during the salt crystallization test. In both stones, the anisotropies (oriented textures) have an important role in their hydric and dynamic behavior and also affect their mechanical properties (especially in the compression resistance). No changes in color were detected.

Libs in cultural heritage: recognition and identification of objects in an underwater archaeological shipwreck

Nowadays, one of the most important areas of interest in archeology is the characterization of the submersed cultural heritage. Mediterranean Sea is rich in archaeological findings due to storms, accidents and naval battles since prehistoric times. Chemical analysis of submerged materials is an extremely valuable source of information on the origin and precedence of the wrecks, and also the raw materials employed during the manufacturing of the objects found in these sites. Nevertheless, sometimes it is not possible to extract the archaeological material from the marine environment due to size of the sample, the legislation or preservation purposes. In these cases, the in-situ analysis turns into the only alternative for obtaining information. In spite of this demand, no analytical techniques are available for the in-situ chemical characterization of underwater materials. The versatility of laser-induced breakdown spectroscopy (LIBS) has been successfully tested in oceanography 1. Advantages such as rapid and in situ analysis with no sample preparation make LIBS a suitable alternative for field measurements. To further exploit the inherent advantages of the technology, a mobile fiber-based LIBS platform capable of performing remote measurements up to 50 meters range has been designed for the recognition and identification of artworks in underwater archaeological shipwrecks. The LIBS prototype featured both single-pulse (SP-LIBS) and multi-pulse excitation (MP-LIBS) 2. The use of multi-pulse excitation allowed an increased laser beam energy (up to 95 mJ) transmitted through the optical fiber. This excitation mode results in an improved performance of the equipment in terms of extended range of analysis (to a depth of 50 m) and a broader variety of samples to be analyzed (i.e., rocks, marble, ceramics and concrete). In the present work, the design and construction considerations of the instrument are reported and its performance is discussed on the basis of the spectral response, the remote irradiance achieved upon the range of analysis and its influence on plasma properties, as well as the effect of the laser pulse duration and purge gas to the LIBS signal. Also, to check the reliability and reproducibility of the instrument for field analysis several robustness tests were performed outside the lab. Finally, the capability of this instrument was successfully demonstrated in an underwater archaeological shipwreck (San Pedro de Alcántara, Malaga).

Material culture and contested heritage in tourism

SummaryContestation is a central element of heritage tourism. This chapter examines issues of contestation in relation to material cultural heritage with special attention given to the built environment, and archaeological and architectural sites. The relationship between tourism and material heritage is characterised by contestation in multiple ways and different scales and includes concerns over values, over space, over materials, over meanings, and over ownership. Using examples drawn from emerging economies as well as more developed destinations the chapter emphasizes the need to pursue these issues through a number of analytical lenses that draw upon different conceptual understandings of heritage and tourism and pursue a range of methodological strategies capable of unearthing the complexities of the contested relationship between tourism and material culture.

Heritage in times of rapid transformation: a tale of two cities - Yangon and Hanoi

Myanmar is opening up to the world after fifty years of military rule and heading into times of rapid economic, social, and political transformation. There is some indication that the changes taking place in Myanmar will parallel those faced in Vietnam twenty-five years ago when it, too, emerged from a period of isolation and opened up to global investment, tourism, and intellectual influences. One of the similarities is likely to be in the growing awareness and use of cultural heritage as a political, economic, and social asset. In all states, capital cities are pivotal in the transformative processes and governments make use of heritage as part of nation-building strategies. This chapter opens up consideration of the role of heritage in times of rapid transformation in Yangon and Hanoi – respectively the colonial and post-colonial capitals of Myanmar (until November 2005) and Vietnam. Important cultural and political differences between the two national contexts are noted and questions asked about what Yangon might learn from the Vietnamese transformation experience.

Making sense of heritage mining landscape conservation in Malaysia: potential and challenges

Landscape is interpreted as the creation of a cultural expression through human ideology and representing a living heritage. Since landscapes are continually evolving, it arouses challenges for sustainability in preserving significant cultural landscape which rested in evolving and transitional world. Kinta Valley former mining landscape can be described as ‘relic landscape’ and this landscape type is one of the sub category under organically evolved cultural landscape (or vernacular landscape) as incorporated in UNESCO Operational Guidelines [18:8]. The main contribution of this paper lies within the gap of knowledge and practise of cultural landscape conservation in Malaysia emphasizing on the cultural values embedded within the heritage mining landscape of Kinta Valley of Perak State, Malaysia. Concerning to the significance heritage values that lies within the Kinta Valley former mining landscape through the lens of cultural landscape theory and practice, this paper highlights on the potential and challenges faced by the Perak state government in establishing mining cultural landscape conservation which can be incorporated within the state and districts planning gazetted documents. Palang & Fry [15] remark that the interface between culture and landscape is very important to understand as it will lead to interpretations of future and current issues of past landscape developments and interventions. United Nations [17] emphasize that sustainable cultural landscape composing of ‘socially, economically and environmentally durable’ and therefore preserving the heritage mining landscape will unravel and unveil the valley sustainability. In addition, qualifying the cultural landscape significance crafted by past tin mining activities in Kinta Valley has resulted in the establishment of heritage values of state and national significance. Therefore potential and challenges of preserving this heritage landscape will be disclose and thereupon embellish the Malaysian culture heritage in general especially in enduring Perak State culture heritage and sustainability.

The destruction of heritage: rock art in the Burrup Peninsula

The destruction of rock art in the Burrup Peninsula, performed by several mammoth industries strategically located in the Peninsula since the 1960s, allows me to analyse the concept of heritage within a global history of art and find meaning in the difficult task of interpreting rock art. The Burrup Peninsula not only hosts the largest rock art site in the world, but also one of the largest deposits of natural gas, iron ore and salt. As a consequence, the land (sacred to the Indigenous people), becomes extremely important in order to sustain the booming economy of Australia. In this difficult negotiation between heritage and progress the rock art is embedded with new meanings and the heritage becomes ephemeral. Failing to include the site in the World Heritage Site list created by UNESCO, the roles of identity and memory are contested by the two groups represented on each side of the debate: on one hand, the Aboriginal Traditional owners and the archaeologists; on the other, the Australian government and the cultural establishment that denies the rock art an aesthetic significance by considering it “primitive” and “archaic”. The debate becomes even more pertinent after realizing that the Australian government has flagged other buildings and natural parks as World Heritage Sites, while the rock art in the Burrup Peninsula is catalogued as national, but not World, Heritage. As a result, the concept of heritage can be defined on several levels: local, regional, national and international.

‘On the move’? Maritime heritage and urban redevelopment in Melbourne

This paper explores issues surrounding the conservation and management of Polly Woodside, one of Victoria’s most significant maritime heritage objects. Sold to the National Trust of Australia (Victoria) for restoration in 1968, the ship has been berthed in the historic Duke’s Dock since 1978. Through various incarnations, the ship and associated museum have been a key feature of the Melbourne ‘riverscape’, and a major tourist attraction, ever since. The paper briefly explores the history of the Polly Woodside and museum, before focusing on the debates about the future use and location of the vessel brought about by the continuing redevelopment of Melbourne’s South Wharf from the mid-1990s until today. It examines how these contentious and often heated debates were shaped by different understandings of the ship's cultural significance, as well as ideas of community, ownership and sustainability, which have wider implications for the management of maritime cultural heritage within a context of urban redevelopment and place promotion.

World heritage: alternative futures

In 2009, the General Assembly of States Parties to the 1972 Convention for the Protection of the World Cultural and Natural Heritage (commonly known as the World Heritage Convention) established an open‐ended working group to debate, reflect on, and strategize for the future of the convention. Since that time, an array of scenarios for alternative directions has been discussed. At its fortieth anniversary celebration in Kyoto in 2012, the World Heritage Convention was referred to by many speakers as having reached a crossroads, a juncture at which a decisive path toward its future sustainability, credibility, and long‐term viability needs to be selected (Vujicic‐Lugassy 2013). Lengthy lists of challenges and gaps highlighted the shortcomings of the World Heritage Convention after four decades of implementation, and these now feature equally in contemporary discourses alongside those that refer to the convention’s enormous success and flagship status within UNESCO.While the World Heritage Convention’s popularity seems likely to increase, along with pressure for new World Heritage listings, the original intent of its authors – mutual support for conservation and international cooperation towards this end – seems to have shifted out of focus. In a time of growing utilization rather than implementation of the convention, its credibility is critically at stake.

Cultural diversity, cultural heritage and human rights: towards heritage management as human rights-based cultural practice

The present article investigates the linkages between conserving cultural heritage, maintaining cultural diversity and enforcing human rights. While there seems to be a growing awareness of these linkages in international heritage and human rights circles, they remain poorly understood by many heritage practitioners who see their conservation work merely as a technical matter. The article argues that it is essential for practitioners engaged in heritage conservation projects to understand the broader economic, political and social context of their work. However, heritage scholars and teachers, too, need to recognise that there can be many motives behind official heritage interventions, that such action is sometimes taken primarily to achieve political goals, and that it can undermine rather than strengthen community identity, cultural diversity and human rights. Such a reorientation is an extension of the paradigm shift in which heritage is understood as cultural practice. In this more critical heritage studies discipline human rights are brought to the foreground as the most significant part of the international heritage of humanity.

Approaches to urban heritage, development and sustainability

More than half of the world’s population now live in urban areas, and cities provide the setting for contemporary challenges such as population growth, mass tourism and unequal access to socio-economic opportunities. Urban Heritage, Development and Sustainability examines the impact of these issues on urban heritage, considering innovative approaches to managing developmental pressures and focusing on how taking an ethical, inclusive and holistic approach to urban planning and heritage conservation may create a stronger basis for the sustainable growth of cities in the future.This volume is a timely analysis of current theories and practises in urban heritage, with particular reference to the conflict between, and potential reconciliation of, conservation and development goals.

The new heritage studies : origins and evolution, problems and prospects

Over the last three decades, community and professional views of what constitutes significant cultural heritage have broadened in many countries around the world. Heritage practice has moved from a narrowly technical or fabric focus to a values-based approach engaging all stakeholders, including indigenous communities. While much Western heritage knowledge and practice remains indispensable, gaps can be filled in by drawing on other knowledge areas and ethical considerations, including links between heritage practice and human rights. These new directions require new approaches in the preparation of practitioners as well as others engaged in heritage processes. In addition to education and training, a third concept – capacity-building – is overarching and potentially powerful in reaching new heritage actors. The aim of giving heritage a valued role in the life of the community, which applies at global, national, and local levels, represents the greatest challenge for educators, trainers, and capacity-builders in the contemporary world.