Ancient Materials and Substitution Materials Used in Thai Historical Masonry Structure Preservation

The historical structures of Thailand are some of the most fascinating ancient sites in Asia.Their architectures reveal past cultures,traditions,knowledge,and expertise.Masonry materials are the major materials used to construct the historical structures in Thailand.One of the essential problem of Thai historical structure preservation is a shortage of engineering properties data for the structural stability assessment.Moreover,the in-depth engineering properties and the suitable substitution materials for Thai historical preservation are rarely found.Therefore,the engineering properties of the ancient masonry materials have to be explored together with the development of suitable substitute materials.This paper presents the physical and engineering properties of ancient materials and substitution materials for the preservation of Thailand’s historical structures.The ancient materials,including brick and mortar,are collected from historical places in the Bangkok and Ayutthaya Provinces.The physical and engineering properties of the masonry materials,such as the chemical composition,mineralogical composition,density,porosity,absorption,water vapor transmission,compressive strength,and modulus of elasticity,were evaluated in the laboratory.Fly ash was used as a pozzolanic material to partially replace the slaked lime to restore the historical mortar.The binder to sand ratio was controlled at 1:3 by weight.The slaked lime was substituted by fly ash at the rates of 10–30%by weight of binder.The engineering properties of the substitution mortars were also evaluated and compared with the ancient masonry materials.A masonry prism was also constructed to evaluate the compressive strength and the modulus of elasticity of the masonry structures.The physical and engineering properties of the ancient masonry materials obtained in this study can be included in a database for the preservation of Thailand’s historical masonry structures.The use of fly ash to partially replace the slaked lime could decrease the setting time and increase the compressive strength of historical repair mortar.The empirical equation obtained from this study could be used to predict the compressive strength of the masonry prisms of Thailand’s historical structures.

Traditional manufacturing of clay brick used in the historical buildings of Diyarbakir （Turkey）

Clay brick is the most common construction materia（ used in the historical buildings of Diyarbaklr （Turkey）. Many clay brick manufacturing workshops and numerous brick masters have emerged. Diyarbakir currently has two clay brick workshops that face the problem of being closed down. Therefore, manufacturing of clay brick by traditional methods may be forgotten in Diyarbakir. This study investigates the manufacturing phases of traditional clay bricks in Diyarbakir＇s local workshops, which have not been documented. The manufacturin8 phases of the clay bricks in Diyarbaklr were examined for the first time based on in-situ observations, investigations, and interviews. The research indicated the general phases of clay brick manufacturing. Raw materials are first prepared, formed, and dried. The firing of clay bricks is then performed through hacking, heating, burning, coolins, and de-hacking. The clay bricks are finally packaged and dispatched. The traditional manufacturing of clay brick methods in Diyarbaklr is similar in many regions of the world. The clay bricks are currently and extensfvely used in the restoration of historic structures. Therefore, their production must be continuous.

Modernised Traditional Lime Plasters for Modern Historic Living of Built Heritage:Case Studies from Germany and Reflection for China

Traditional plasters were generally produced until about the middle of the 20^(th) century.Among traditional plasters,lime plaster in Europe occupies a position of outstanding importance.Plasters play a key role as a protective and decorative outer layer in the care and rehabilitation of the built heritage.To meet the needs for protecting masonry and living in historic buildings in the modern age,traditional lime plasters can be modified to fulfill technical and aesthetic functions.This paper makes an assessment of the use of traditional and modern lime plasters in Germany.The rediscovery of lime plaster as a material for use in cultural heritage conservation has led to the application of traditional and modern plasters along with advanced guidelines and standards for their production and application.In China,a kind of lime-system has recently been developed that is historically and technically compatible with the types used historically;the new types lend itself well to use in modern conservation.