With the development of stone conservation engineering practice, the maintenance technology is greatly enriched. Conservation theory is also emerging. All theories are based on the analysis and answering of various problems and phenomena in the practice of conservation, which have their rationality and applicability, as well as their one-sidedness and restriction. Some new problems have emerged in the recent practice of stone conservation, and some new ideas have been formed, which are summarized below.
First, not all natural stone needs protection
If it is only waterproof and anti-alkali, some high-hardness and high-density stone in the ten-hanging construction can not be protected. This also applies to some coarse-grained granite. For example, in the igneous rock, the coarse-grained magmatic rock obtained by slow cooling has a large amount of quartz. This low-density quartz surface water and other pollutants are infiltrated. The theory was confirmed and recognized by Maurizio, a conservation expert at the International Stone Association of the United States. Which materials need to be protected? Which stones do not need to be tested is dripping water under the polished surface of marble or dropping vinegar on the polished surface of granite. If the residue of anhydrous or vinegar remains after 5 minutes, the marble or granite of this variety may not be Do protection. This is basically the case with the “Hua’an Jade” marble from Fujian.
Second, the stone protection should be suitable for the construction of materials, construction of materials
In the engineering practice, it will be found that the protective agent has poor protection effect on some varieties of stone. Excluding improper construction and production failure, the most likely reason is that the correct stone chemicals are not used for protection. For example, granite and marble have different formulas for their mineral composition and chemical composition. Even the same type of stone will increase or decrease the concentration of silicone resin due to differences in density and chemical composition. For example, the concentration of silicone resin in sandstone protectants will be higher, and the concentration of silicone resin in granite or marble protectants with higher hardness and density will be lower. Therefore, in the construction of stone conservation, it must be adapted to the material, and it must be constructed according to the material. Different chemicals and different construction techniques are selected for different stones. This further illustrates the need to establish a stone conservation database. It is like compiling a dictionary or encyclopedia of stone conservation. By checking the selection of the correct chemicals and construction methods before the maintenance and construction, and taking the medicine according to the prescription, not only the effect can be significant, but also the annual production cost can be saved.
Third, do not blindly believe in imported stone conservation products, and do not prejudice domestically produced products.
At present, the maintenance products of foreign brands are generally considered to be a symbol of high quality. However, its high price affects the promotion of foreign brands. The maintenance products of domestic brands are generally not optimistic, but they also have a certain market share because of their cheap prices.
In fact, these prejudices come from the lack of understanding of stone conservation knowledge. All protective agents, whether imported or domestically produced, are composed of active ingredients plus diluents and auxiliaries. There is no difference between this entry and domestic production. In recent years, the research and development and application of domestic stone protective agent products have developed rapidly, and it has been close to foreign advanced water in the field of silicone monomer manufacturing and resin synthesis. It is equivalent to foreign countries in the compounding process. In the field of construction applications, it is ahead of foreign countries.