Impact toughness: The impact toughness of stone depends on the mineral composition and structure. Quartzite and siliceous sandstone are highly brittle, while gabbro and diabase, which contain a large amount of dark minerals, have relatively high toughness. The heat resistance of stone is related to its chemical and mineral composition. Stone containing gypsum begins to break at temperatures above 100 ℃; Stone containing magnesium carbonate will undergo damage when the temperature is above 725 ℃; Stone containing calcium carbonate begins to break when the temperature reaches 827 ℃. The frost resistance of stone is expressed by the number of freeze-thaw cycles.
6. The mathematical formula for the density of stone is ρ= M/V, with the symbol g/cm ^ 3.
7. Rocks with a water absorption rate lower than 1.5% are called low water absorption rocks; Rock with a water absorption rate between 1.5% and 3.0% is called medium water absorbing rock; A rock with a water absorption rate higher than 3.0% is called a high water absorption rock. The water absorption of stone is mainly related to its porosity and pore characteristics.
8. The acid and alkali-resistant decorative stone is exposed to the air, especially outdoors due to the corrosion of acidic and alkaline gases such as sulfur dioxide, causing discoloration and even surface peeling of the board. In industrial settings, the requirements for the acid and alkali resistance of the stone are higher. The standards for acid resistance, alkali resistance, hardness, and shear strength are not specified in the national stone standards for general indoor decoration and decoration.
3、 Selection of stone materials
1. According to the needs of applicability, economy, and safety, the selection of stone materials of the same type often varies greatly due to different varieties and origins. When designing, the selection should be based on the performance that needs to be considered first and foremost, and the landscape stone materials that are most suitable for this project should be selected. Like the red series granite, the compression strength of Shidao red syenogranite is 234.37MPa, while the compression strength of Tianquan rose red syenogranite is only 84.4MPa.
However, the compression strength specified in GB/T18601-2001 “Natural Granite Building Materials” is greater than or equal to 100MPa , which is not suitable for application in open landscape projects such as landscape green belt engineering and squares, as a paving material for square floors for rest, Firstly, its compressive strength and wear resistance should be considered;
The decorative stone used for landscape walls and screen walls should first consider frost resistance and safety, and secondly, for the landscape decorative stone used for walls, its economy should also be considered. The higher the general level, the better the decoration effect, but the higher the price. Consumers and designers should choose according to the actual situation to avoid increasing unnecessary costs.
2. According to the environment where the garden landscape project is located, stone materials should be selected. In some environments near industrial areas and with high pollution, the stone materials involved in the garden project must first consider materials with strong pollution and corrosion resistance. Generally, it is advisable to choose stones processed from magmatic rocks, such as various granite, diabase, and other stones.
It is not advisable to choose stones with low corrosion resistance, low compressive strength, and poor wear resistance, such as marble, dolomite, and limestone, which are mainly composed of calcium carbonate and magnesium carbonate. Only in this way can the aesthetics and firmness of the stone be permanent. In some natural scenic areas and areas with beautiful environments, natural and beautiful stone materials can be considered first for construction.
4、 Landscape Application of Stone
The application of natural stone has a long history, expanding its application fields from foundations, steps, railings, stone tables, sculptures, stone tablets, floors, walls, etc. to wall decorative panels, sanitary ware, combined new types of floor decorative stones, etc. The use of high-end stone in buildings can further enhance the level of buildings. The palace base and railings of the Forbidden City of the Ming and Qing Dynasties in Beijing, known as the world cultural heritage, were built of White Marble and marble.