The so-called concrete construction mixture ratio refers to the proportional relationship between components in concrete.
Adjustment steps: set the laboratory mix ratio as follows: cement: water: sand: crushed stone = 1: x: y: z, the water content of field sand is m, and the water content of crushed stone is n, then adjust the construction mix ratio to:1:(x-y * m-z * n): y * (/kloc).
Concrete mix design is a very important work in concrete engineering, which directly affects the smooth construction, quality and cost of concrete engineering.
Classification by apparent density
Concrete can be divided into heavy concrete, ordinary concrete and light concrete according to its apparent density. The difference between these three kinds of concrete is the difference of aggregate.
The apparent density of heavy concrete is more than 2500kg/m&; Sup3, made of particularly dense and heavy aggregate. Such as barite concrete and steel chip concrete. , not affected by x-rays and gamma rays.
Ordinary concrete is commonly used in buildings, and its apparent density is1950 ~ 2500 kg/m&; Sup3, the aggregate is sandstone.
The apparent density of lightweight concrete is less than 1950kg/m&: Sup3 concrete. It can be divided into three categories:
1, lightweight aggregate concrete, its apparent density is 800 ~1950kg/m&; Sup3. Lightweight aggregate includes pumice, volcanic slag, ceramsite, expanded perlite, expanded slag and slag.
2. Porous concrete (foamed concrete, aerated concrete) with an apparent density of 300 ~1000 kg/m&; Sup3. Foamed concrete is made of cement slurry or cement mortar and stable foam. Aerated concrete is made of cement, water and gas-generating agent.
3. Macroporous concrete (ordinary macroporous concrete and lightweight aggregate macroporous concrete) does not contain fine aggregate. The apparent density range of ordinary macroporous concrete is1500 ~1900 kg/m&; Sup3 is made of crushed stone, soft stone and heavy slag as aggregates. The apparent density of lightweight aggregate macroporous concrete is 500 ~1500 kg/m&; Sup3 is made of ceramsite, pumice, broken bricks, slag, etc.