Slate is a kind of shallow metamorphic rock, formed by clay, sandy silty sedimentary rock, or medium acid tuff rock, tuff by slight metamorphism. slate has good natural stratification, uniform thickness of the single layer, moderate hardness, corrosion resistance, acid and alkali resistance, high and low-temperature resistance, compression resistance, flexural resistance, weathering resistance, sound insulation, heat dissipation, and other characteristics. Slate is famous in the world for its elegant color, beautiful appearance, fine texture, natural texture, and other characteristics. It can be used in bustling buildings and can be built in villages and villages, indoor and outdoor, and adapt to a variety of environments.
The color of slate varies with the impurities it contains, red or yellow for those containing iron; Carbonaceous is black or gray; Calcium can blister in hydrochloric acid; According to its natural color can be divided into light cyan, light green, black, brown, brown, red, yellow, light gray and so on.
When SLATE is formed by regional metamorphism, the temperature and homogeneous pressure are not high, and it is mainly affected by stress. Its engineering characteristics are as follows:
1. Mineral identification by X-ray diffraction analysis shows that the clay minerals in Slate contain kaolinite and other clay minerals with relatively good engineering properties, and the mineral composition and content change a little before and after weathering, without illite and montmorillonite and other clay minerals. It is preliminarily believed that Slate can be used as the bottom filler of subgrade. The strongly weathered and fully weathered Slate has the properties of clayey coarse-grained soil and clayey soil.
2. Slate belongs to low swelling rock and soil, with poor resistance to weathering and waterproof ability, and poor water stability of roadbed filling. Special engineering measures, namely water-proof and waterproof measures, must be taken to eliminate the harm of its free expansion of water absorption to the embankment.
3. Slateis easy to disintegrate into fine soil under the natural circulation of rain, snow, and frost, and its strength drops rapidly. Under the condition of incorrect construction method, Slate is a kind of material with poor road performance.
4. Slate belongs to low shrinkage rock and soil, the surface cracks of embankment filled with Slate may appear small and shallow, and the dust is small, so it is difficult to soak water through the cracks.
5. Slate has strong saturated water absorption and poor water stability. Attention should be paid to its soaking and softening phenomenon during construction.