Study On Deterioration Mechanism And The Conservation Of Typical Brick And Stone Cultural Heritage In Moisture Circumstances

Due to complicated environment factors ,these brick and stone cultural heritage, which are widely distributed in the nature including sandstone, conglomerate, limestone, marble, white marble, slate, shale, tuff, andesite, granite, basalt, ,are subject to serious degradation .take moist and arid environment for example, we should adjust conservation treatments and materials. when it comes to the stone cultural heritage by the sea, first of all we should remove the water-soluble salts .when it comes to the stone cultural heritage inside the tombs ,we should take drafty and restraints of capillary water and condensation water, avoiding the sudden changes of humidity and biodeterioration.we should adjust measures to local conditions and take the differences of environment into granted while exerting appropriate materials and skills to conserve these stone cultural heritages.From the viewpoint of rescue protection according to the law of the people's Repubic of china on the protection of cultural relics (2002)and Principles for the Conservation of Heritage Sites in china (2004),field investigation and geotechnical tests are conducted for the present conservation condition, architectural techniques ,the lodging environment. In this study different efflorescence of historic stones (physical weathering, chemical weathering and biological weathering) and the efflorescence mechanism of the stone cultural heritage in moisture circumstances were measured ,we choose Gaogouli's Stone cultural heritage,Xi'an city wall,linyou's carved stone,DaZu'carved stone,Macao'stone cultural heritage as the inspection targets. ,and some results were concluded, Water ,including underground water,surface water,rainfall and moist environment are the key element which generate serious degradation .The investigation of a lot of parameters about treated sandstone, brick with several water repellent and consolidant materials has been carried out , mainly according to ASTM standard and the combination of international methods together with general technological. The protection mechanism was analyzed on the understanding of these results. Finally we analyse the feasibility of these materials in the reinforcing of true cultural object protect. And due to the serious biodeterioration in moisture circumstances, and we put forward the prevention and cure for the biological degradation of Stone cultural heritage in these moisture circumstances.When confronted with decaying stonework, we always aim at individual conservation target and never summarizing in category the experience for these brick and stone cultural heritage in moisture circumstances. This paper discusses necessity, feasibility, and basic methods of the conservation of typical brick and stone cultural heritage in moisture circumstances .Although these stonework and brickwork are outside in moisture circumstances, we still can do something to the environment , which embrace a very wide range of topics legislation to protect individual stonework, pollution control, traffic control, control of ground water, visitor management and disaster planning.One hundred years ago we have found some materials to penetrate the decayed stone , with evidence for Roman use of pastes applied to recently sculpted stone, which binding it together and securing it onto the sound stone beneath. Organic silicon, which was widely used in stone conservation, was selected as surface protectant . Some common stone were used as protected objects, such as sandstone, tuff, dolomite, marble and granite. A series of artificial weathering experiments, which included single or cooperative effect of major ruinous factors-dry-wet cycle, salt crystallization, freezing and heating were simulated and researched.Based on investigation and the actual survey work, The research includes value assessment, environmental influence factors, causes of deterioration, choice of chemical treatments by means of X-ray diffraction, scanning electron microscope and other testing methods , the results help us to draw all kinds of mechanism of degradation formation ,such as porosity ,capillary absorption and penetration coefficient ,water uptake, warming-cooling cycles, the influence of salts crystallization, acid and base, and UV aging and so on, in order to better understand the protection effects and utilization possibility of two fluorinated polymers.And due to the serious biodeterioration in moisture circumstances ,many organisms contribute to the deterioration of stone and brick such as colorful lichens, mildew and creepers, we choose one composite fungicide which can prevent the growth of microorganisms from the site were identified, And also, we conduct the experiment of Zones of inhibition and put forward the Preventive and remedial methods for Stone cultural heritage in these moisture circumstances. The conservation of typical brick and stone cultural heritage in moisture circumstances is the difficult point , we should make a deeper research into the conservation materials, select most appropriate material from a wider range of choices; and we should move forward a single step into the trial results.