1, different safety: thick yellow sand, strong, drought-resistant and flood-resistant; Green sand is fine and loose; In contrast, it is safer to build walls with yellow sand.
2. Aesthetic difference: green sand is dense and looks more beautiful than yellow sand after use.
3. At present, there are differences in the scope of application: at present, yellow sand is widely used in building walls; Wet sand is rarely used in construction projects.
Extended data:
Sand belongs to fine aggregate in concrete, and aggregate with particle size between 0. 16 ~ 5 mm is fine aggregate (sand).
Generally, natural sand is a mixture of different sizes and different mineral particles formed after weathering of rocks, which generally includes river sand, sea sand and mountain sand.
In concrete, sand plays a skeleton role and is called aggregate; Cement and water form cement slurry, which is wrapped on the surface of aggregate and fills its gaps.
When mixing concrete, these two factors (sand grading and thickness) should be considered at the same time.
When the sand contains more coarse-grained sand and the voids are filled with appropriate medium-grained sand and a small amount of fine-grained sand, the porosity and total surface area can be smaller. This kind of sand is ideal, which not only uses less cement slurry, but also improves the compactness and strength of concrete.
It can be seen that it is of great technical and economic significance to control the grain gradation and thickness of sand, so they are important indexes to evaluate the quality of sand. Only the index of thickness cannot be used as a criterion.
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