Trabalho 1. Concrete

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MANUFACTURE OF CONCRETE
Stages of manufacture
There are five steps in the concrete manufacturing process are:
Concrete Mix
Objective: Intimate contact between the component materials - cement paste coating
on particles of aggregates, that is General Mix materials. The main requirement is a homogeneity.
Mixing the concrete can be: Manual and Mechanized.
Manual -when performed with the aid of shovels and hoes (small importance works);
Recommended Care:
It is very important that the amount of water the mixture is correct. Both the excess and lack are harmful to concrete.
 Excess water reduces the strength of concrete. Lack of water leaves full of holes concrete.
Mechanized - when performed with the aid of a concrete mixer.
Recommeded Care:
The mixer must be cleaned before use (free of dust, dirty water, the last use remains).
 Materials must be placed with the mixer spinning and in the shortest possible time frame.
Transport Concrete
After mixing, the concrete will be transported to the application site through the various modes:
Horizontal - wagons, carts, trucks, pumps;
Vertical - buckets, winches, pumps;
 Oblique - belts, conveyors, chutes.
It must be as fast as possible while maintaining the homogeneity of the concrete (avoiding
segregation of the materials).
Launch concrete
It is the placement of concrete in the application site, in general, the forms. Begins to harden after four hours the addition of water.
Densification
Objective: Move with effort, the elements that make up the concrete and direct them to get
greater capacity, causing the particles to occupy
empty and dislodge the trapped air in
pasta.
Densification processes: 
 The Densification processes can be:
Manual: Socamento and tamping.;
Mechanical: Vibration and centrifugation.
In socamento, the bar should penetrate partly in the lower layer.
In tamping, it is more important the number of stroke
s that energy of each provided that
this exceeds a certain value.
Cure
It is the name given to the set of measures with the finality to prevent evaporation premature water necessary for the hydration of ciment which governs the handle and its hardening. Requires protection in the first 7 days counted launch.
Conditions humidity and temperature, especially the first age, they have great importance in properties of the hardened concrete.
In the work curing of the concrete can be made by various
s processes:
 Periodic irrigation of surfaces.
Coating of surfaces with sand bags or and torn burlap, which are always kept moist.
 Employment waterproofing compounds healing.
Coating surfaces with impermeáv papers here special, that preventing evaporation, require the use of water.
Superficial calcium chloride application in reason 800 g / m². It is used in climates
wet, the product absorbs water from the environment and retains.
Bibliography:
For the realization of this work was needed the help of some e-mail addresses, as follows:
http://netulio.weebly.com/uploads/9/0/6/6/9066781/processo_de_produo_do_concreto.pdf
http://www.ebah.com.br/content/ABAAAA7NIAH/fabricacao-concreto
http://www.mapadaobra.com.br/produtos/concreto/
http://www.tecomat.com.br/angelo/arquivos/execucao_concreto.pdf
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