Ordinary concrete refers to the ordinary Portland cement as a cementing material, plus sand, gravel, water and admixtures (admixtures sometimes added), according to a certain percentage of preparation, after mixing, tamping shape, made of a hardened conservation man-made stone. Because of its rich resources of raw materials, production process is simple, good performance characteristics of low price, and has higher strength and durability, ease of pouring into a variety of shape components or the overall structure, combined with the reinforcement into the strong, anti-vibration of the reinforced concrete structure, it has been widely used in construction building materials. As concrete is a kind of a combination of ingredients of non-homogeneous material, its production process also covers the preparation, mixing, vibrator and maintenance of such processes, together with cement is a kind of active materials. Therefore, the quality factors of raw materials and production processes of certain aspects of their performance and quality are great, the impact can not be ignored. Concrete mix design goal is to take into account the above factors, the application of proposed construction of the best mix proportion of concrete.

A concrete mix design the basic principles of

1.1 ruggedness

Robustness refers to the strength of concrete target, because the quality of concrete compressive strength of the current index is based on the main grounds. There are many factors affecting the compressive strength of concrete, mainly concrete strength grade and the water-cement ratio, aggregate type and grading, construction conditions.Sodium Naphthalene Formaldehyde

1) Cement Strength Level: cement strength rating generally represents the activity of cement, that is, with the ratio in the same circumstances, the higher the concrete strength grade, the higher the concrete strength grade. In the concrete mix designs, mainly from the economical point of view to select the concrete strength grade, if there is no concrete strength grade and variety choice, it can only adjust the mix proportion design of lean proportion of admixture admixtures such as an integrated measures to solve them.

2) water-cement ratio: Concrete unit volume of water in the weight and the weight ratio of cement is known as water-cement ratio. Higher water-cement ratio, concrete strength, the lower end, to meet the premise of workability, concrete goal is to minimize water consumption, which is of concrete mix proportion design of a basic principle.Poly Carboxylate Superplasticizer

3) The aggregate types and size distribution: sand, gravel in the concrete skeleton of the role of play, so collectively referred to as aggregate. Sand and gravel from the stone species, particle size distribution, clay content, robustness, and other indicators of harmful substances to indicate its quality. Sand and gravel quality, the better prepared the better the quality of concrete. When the aggregate gradation good sand ratio was appropriate, owing to the formation of dense skeleton, can get a higher strength concrete.

4) Construction conditions: If the construction of better conditions and have a certain degree of management measures, may be appropriate to reduce the slump of concrete; the other hand, such as on-site construction of the disadvantaged should be an appropriate increase concrete slump.