Road and bridge engineering materials began to use gypsum and limestone as cementitious material thousands of years ago, and then began to use natural cement stone (lime with clay content of 20%-25%) to calcin and grind it to make natural cement. Entering the 21st century, high-performance concrete will be widely used as a structural material.
Sand and gravel are commonly used materials in road bridge construction. Whether it is cement or concrete, sand and gravel materials are indispensable. The sand and gravel materials required for road bridge construction are loose gravel obtained by crushing machinery or natural weathering of the rocks on the surface of the earth's crust. However, general bridge construction does not use natural rock gravel gravel. On the one hand, the amount of natural rock gravel gravel is limited. On the other hand, the crushed gravel gravel produced by artificial crushers is more in line with the needs of construction.
The main components of road and bridge building materials include metal materials, non-metallic materials (such as cement, lime, concrete, mortar, natural stone, glass, burned earth products, etc.) and metal-non-metal composite materials (such as reinforced concrete, etc.).
What are the requirements for the construction of road and bridges for sand and gravel particle size?
Requirements for stone and aggregates:
Stone is divided into block stone and pellet stone. Block stone is referred to as stone, and granular stone is referred to as aggregate. It is divided into coarse aggregates, gravel, pebbles, fine aggregates such as sand and gravel, stone chips. The stone used in road and bridge construction is bounded by the size of the particle size, and the aggregate is usually divided into coarse aggregate and fine aggregate; among them, in asphalt mixture , the boundary is 2.36mm, and in cement concrete, 5mm.
Technical requirements for stone:
Grade I -Strong rock Grade II -Strong rock Grade II -Strong rock Grade III -Medium strong rock Grade IV -Softrending rock
Grade I 6 -Softrending rock ml ml2
Grade I 6 Grade I 6 -Softrending rock ml2
Grade I 6 Grade Solid rock ml2
Grade Sand grains Diameters can be divided into: (1) special coarse material D≥37.5mm(2) coarse grain type D=31.5/26.5 for base and lower layer (3) medium grain type D=19/16mm(4) fine grain type D=13.2/9.5mm surface layer (5) sand grain type D≤4.75mm Abrasion layer
General fine aggregates Fine aggregates for concrete generally use artificial mechanism sand with good grades, hard texture and clean particles with particle size less than 4.75mm. In addition, sand and gravel produced by crushers can also be used as cement soil, cement gravel, etc.
If you have any related problems in crushing and sand making, please find the editor to learn more about it!
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-