Ready Mixed Concrete computer Glossary
Concrete Ready dictionary
Ready-mixed concrete cement, aggregates (sand, gravel, crushed stone), water and obtained by mixing according to a certain production technology of some additives required is initially in a plastic or fluid consistency, which can be shaped and gradually solidifying and hardening, strength, winning is an important building material .
Concrete in absolute volume, 75% of aggregate, cement and water by 10% to 15%. If necessary, that they are not more than 2% by weight of cement additive may be added.
TS is divided into 3 classes of concrete according to EN 206-1:
Normal concrete: oven dry mass per unit volume in the state (density), 2000 kg / m3 large 2600 kg / m3 with small concrete.
Heavy concrete: oven dry mass per unit volume in the state (intensity) of 2600 kg / m3 larger than concrete.
Lightweight concrete: oven dry mass per unit volume in the state (density), 800 kg / m3 large, 2,000 kg / m3 with small concrete. Lightweight concrete, a portion or all of the aggregate used in concrete are manufactured as lightweight aggregates.
Ground limestone and other raw materials of the clinker obtained after cooking in the oven turns mixed in specific proportions, called cement binder in the form of gypsum and other additives are mixed with the powder obtained by grinding.
Cement, when mixed with water, forming dough that can be cured by taking outlet with hydration reactions and processes and can even maintain the strength and stability of the ground inorganic material in water after hardening.
The function of the cement in concrete; By coating the surface of aggregate and make the task of filling the gaps between grains of binding.
Used in the concrete and the concrete forming the approximately 60-80% of crushed stone, called the aggregate material such as sand and gravel.
Natural aggregates (sand and gravel, crushed stone) and artificial (blast furnace slag, expanded clay, perlite) has two different origins to be. However all mineral based materials or industrial waste used as concrete aggregate.
But today, most consumers minds concrete aggregate used in concrete production quality, has just formed a wrong judgment that is dependent on the color of the aggregate. However, affecting the quality of the aggregate, there are many physical and chemical properties of these features are set out in TS 706 EN 12620 standard.
The role of aggregates in concrete is very important. Grain size distribution, shape structure, hardness, directly affects the behavior of the concrete. It must be determined experimentally before the use of the properties of concrete aggregate.
I tipib Aggregate volume mass (kg / m3)
Normal agrega2000-3000hafif Agrega≤ 2000Ag is Agrega≥ 3000
Aggregate largest nominal size (Dmax), the small size of the concrete cover layer and the concrete section of the reinforcement should be determined considering. being obtained from the fresh concrete was recovered from the wash liquor or used as aggregate in concrete.
Water is one of the main material forming the concrete. The shuffling of the water used in the concrete mix, fulfills two important functions:
- Cement and aggregate the surface to create a lubricating effect and so the ability to mix easily by soaking the concrete, the placement of the concrete, compression ability, the ability to provide treatment summaries
- Ensure that the resulting chemical reaction called hydration combined with the cement paste of powdered cement grains
Clean, potable water is available in clear and odorless each concrete production. Concrete should not be mixed in the acid water quality. Sulfate, etc. of different salts. It should not contain chemicals that can damage the concrete.
participating in a proportion of organic or inorganic origin chemicals based on the amount of cement in concrete to improve certain properties of concrete are known as additives. Additives are often joined the mix water. When excessive use may have no benefit if they can create effects as yet under-used otherwise. But that's not to improve the properties of concrete produced according to the rules that should be well known by additives is not possible. Compliance with the appropriate additives produced concrete rules should be determined by experiments in advance.
chemical additives used in concrete manufacture are grouped as indicated below.
a) Water reducing / plasticizing chemical additives:
contributions fall into this group are mostly used in the ratio from 0.2% -0.5 weight of cement. these additives increase the workability of fresh concrete at the same time they increase the concrete's strength as they reduce the need for concrete mixing water.
More high strength concrete with a water additive used in the concrete / cement ratio, it is possible to reduce to 0.25. However, the super agent is used in much higher dosage of 1% to 3% as compared to normal agent.
c) chemical additives that alter the length of the connector:
Fresh concrete is called hardening process is accelerating or delaying requested under certain conditions. Especially in the summer, retarder in long distance transport, the accelerator is used in the winter.
d) Air entraining chemical additives:
these agents in protecting against the danger of freeze-thaw in cold climates, but also increase the workability of the concrete.
Such additives which prevent the freezing of water by lowering the freezing temperature of water in the concrete and concrete cracking. But the cold weather in the concrete just taking special measures for the protection of concrete cast in place is not the ultimate solution to add antifreeze additives is required.
f) Other Additives:
Lightweight concrete, waterproof concrete, shrinkage prevention, adherence enhancer, coloring, water retention, water resistance and so on. There are various chemical additives.
Thin materials used to impart special properties to improve some properties of the concrete or concrete are known as mineral additives. So that the contribution of the feature to provide additional strength concrete, the durability (durability) increase in terms of the performance. all kinds all over the world and in our country when mineral additives of physical, chemical and electro-production of durable concrete structures against external chemical effects of portland cement clinker or portland cement is used with.
Types of mineral additives
- Silica fume
- Fly ash
- Blast furnace slag