Study On Evaluation Method Of Protective Materials Of Stone Cultural Relics

The article screened out the main property indexes of surface protection materials, reinforcing materials and bonding material, and the evaluation method of them was founded. The reasonable evaluation standard was given at the same time. At last, the evaluation method and the evaluation standard were used on the simulation test block of Dazu Rock Carvings.According to the distress mechanism of stone historical relics and the performance requirement of protective materials, the major evaluation indexes of protection materials were selected:solid content, surface tension, viscosity, permeability, aging resistance, adhesion properties, permeability, etc. The establishment of surface protection of stone conservation materials, reinforcement materials and bonding materials, evaluation methods and evaluation criteria, which uses infrared moisture determination of solid content, the evaluation criteria are: surface protection of the value of solid content material should be 7.5%～22.5%, the reinforcement material of solid content value should be 3% to 10%, the adhesive material of the solid content value should be in the range of 4% to 10% above the value of solid content not more than 0.5% deviation; Determination of surface tension by rings, the evaluation criteria are:surface tension value of less than 71.6mN/m; using NDJ-5S Rotary Viscometer viscosity, the evaluation criteria are: the viscosity of the surface protection of materials in 5.0cP-10.0cP within the reinforcement material and adhesive material viscosity 4.0cP-8.0cP range; permeability evaluation is material penetration depth measurements, the evaluation criteria were:penetration depth of surface protection of materials in 10mm-15mm range, the penetration depth of reinforcement materials,13mm-20mm range, the penetration depth of adhesive material in 12mm-18mm range; aging resistance by QUV accelerated aging, outdoor exposure test, resistance to heat aging and freeze-thaw aging evaluation methods, including QUV accelerated aging of the evaluation criteria used GB/T1766-2008 Paints and varnishes aging properties of the rating method, changes in level 2 or above level 2 qualified, other evaluation criteria for material handling trial block powder, cracking, spalling, blistering performance at or better than such phenomena as the gaps are not weathering test blocks as standard; determined by pull adhesion properties, their evaluation criteria are as follows:surface protection of materials and strengthening of laws focus on value should be≥5 Mpa, adhesive bonding material value should be≥6 Mpa; evaluation of the wet cup method the permeability, the evaluation criteria:compared with blank samples, material handling samples of water vapor through the decline in value is not more than 30%.The materials are applied in the simulation test block of Dazu Rock Carvings: the penetration and permeability of B72 in surface protective materials fail to make the grade, all indexes of ZB-WB-S reach the standard, but QUV accelerated aging is unsatisfactory;all indexes of ZB-SE-3A reach the standard, all indexes of reinforcing materials reach the standard, The Adhesion of ZB-SE-3A on bonding materials fail to make the grade, all indexes of other materials reach the standard.