Cultural relics protection technology is a comprehensive subject of knowledge, including cultural relics production, protection and science and technology, material function, operation technique concerning the prevention and treatment as well as all kinds of survey and testing, etc. During the protection period of cultural relics, there are two kinds of damages, i.e., the artificial damage, such as ancient architecture, grottoes and mausoleums damaged by the war, dismantled or lost original appearance due to improper maintenance, and the damage on iron and bronze ware, calligraphies, paintings, bamboo, wooden, painted and ceramic wares due to improper protection and delivery; and another being the damage on the cultural relics due to natural factors such as wind, rain, thunder, electricity, fire, earthquake, light, pest and fungus, etc.China enjoy long history in the technology of cultural relics protection. It is recorded that in Tang Dynastry (618~907), wooden wedge was already used in moving the inclined ancient architecture correctly. In addition, according to the record in Yizhou Famous Painting Album by Huang Xiufu, in Chengdu City, wall paintings on three walls were moved, and now are still complete as before after more than 200 years. The peeling off and mounting technique for calligraphies and paintings was already very mature in Tang Dynasty.
Painting for sticking to the stone and fish glue for the wood are also very popular traditional techniques for restoring stone and wooden cultural relics. Latter, with the improvement of science and technology, the high molecule materials and physics testing technology have been gradually introduced into the job of cultural relics protection.Some European countries started to use the mixture of milk and lime water to restore the wall painting, which came down till now.The policy of prevention the main and maintenance the auxiliary shall be complied with in the cultural relics protection. The damper proof, leakage proof, fire proof, thunder proof and earthquake proof for unmovable cultural relics are mainly depending on the engineering technology. However, the prevention of pests and birds mainly adopt the method of combination of engineering technology and chemistry.When pollution from powder, SO2 and sulfuric compound on the cultural relics exceed the state regulated standard, the pollution source shall be removed. Within the allowable scope of the state standard, more trees or grass shall be planted to reduce the pollution, meanwhile the new pollution source shall be strictly controlled.For the prevention and protection of movable cultural relics, the preventive measures such as damper proof, earthquake proof, mildew proof in the storerooms inside the museums and the exhibition rooms shall be firstly noticed. Then, the cultural relics of different texture shall be protected respectively, such as anti-corrosion for bronze ware and iron ware, anti-decency of brick and stone relics, mildew proof, moth proof and aging proof for the silk and paper, etc.When the wooden structure architecture is completely inclined or twisted, after being corrected, reinforcement treatment shall be carried out. The damage on the components shall be repaired and piled.
If the groove in large components is hollow, high molecule materials such as unsaturated resin can be used to casting for reinforcement. If the decay or rot is serous, then the groove shall be changed according to the principles.If the brick-structure stone architecture is completely inclined or twisted, spot and regular survey shall be carried out. Foundation treatment can be omitted if it is stable after the reinforcement. Hoop and grouting can be used for the leakage. The deformity on the masonry can be repaired, if not, partial or complete dismantling can be carried out and reconstruction is required to be done according to the original sample. The mountain cranny in the cave can be reinforced by riveting or grouting. The water leakage spots shall be introduced and stopped. Organic silicon high molecule material shall be used for sealing and protecting the superficial decency on stone sculpture or inscription, etc.For the restoration on ancient architecture, it shall be repaired as less as possible, and the original components shall be kept as much as possible so as to reserve the historic value of ancient architecture. The sculpted tile animal article, wooden, brick and stone inscription inside the ancient architecture shall be prudently treated, not change or change less. The statue, wall painting and color paintings are artistic work, so repairing is not allowed at will. Traditional technique and modern technology combination can be adopted for the restoration on movable cultural relics. For instance, if the bronze ware is rusted, mechanical removal or electrolytie reduction can be used to remove the rust. Natural drying method can be adopted for the dehydration of bamboo, wooden and painted articles, or by adopting alcohol and ether soaking, frost sublimation and high molecule material leakage. The traditional peeling off and mounting method is more widely used for the broken and damaged calligraphies and paintings. Modern books can adopt the thread net to reinforce, and suffocating method for the modern net silk. Thread net or traditional mounting method can be used to reinforcing the fragile textile products. If the ceramic ware is broken, high molecule materials such as shell-lac or epoxy can be used for adhesion. The new materials and techniques adopted in the cultural relics restoration must ensure no damage on the historic value of the cultural relics, including the shape, material, color and strength. Meanwhile, traceability must be ensured. For the maintenance of ancient architectural components, the principles of new materials cannot strengthen but not substitute the old shall be complied with.The testing technology is mainly used for the survey on the cracks of cultural relics, the analysis on the texture and structure chemical components and the estimation of age. X-ray and ultrasonic wave are usually adopted for crack detection. Electronic microscope, metallic phase microscope are usually adopted for the texture structure analysis. For the chemical components of cultural relics, light spectrum and mass spectrum are usually used. For the ambiguous ink paintings with little contrast, infrared photographing method can be used. C14 can be used to testify the age of the carbon materials, such as wood, and thermo luminescence for the ceramic and bricks or tiles.