Concrete

**Concrete**
Concrete is a composite construction material composed primarily of aggregate, cement and water. There are many formulations that have varied properties. The aggregate is generally a coarse gravel or crushed rocks such as limestone, or granite, along with a fine aggregate such as sand. The cement, commonly Portland cement, and other cementitious materials such as fly ash and slag cement, serve as a binder for the aggregate. Various chemical admixtures are also added to achieve varied properties. Water is then mixed with this dry composite which enables it to be shaped and then solidified and hardened into rock-hard strength through a chemical process known as hydration. The water reacts with the cement which bonds the other components together, eventually creating a robust stone-like material. Concrete has relatively high compressive strength, but much lower tensile strength. For this reason is usually reinforced with materials that are strong in tension. Concrete can be damaged by many processes, such as the freezing of trapped water.

=Properties= Type: fine grain concrete. Ingredients: cement, water, small stones. Strengths: cheap, fireproof and weatherproof, molds to any shape, strong in comprenssion. Weaknesses: craks with temperature changes, weak in tension.

=**Definition**= Concrete is a manufactured mixture of cement and water, with aggregates of sand and stones, which hardens rapidly by chemical combination to a stonelike, water-and-fire-resisting solid of great compressive but low tensile strength. Concrete was employed in ancient Egypt and was highly developed by the ancient Romans, whose concrete made with volcanic-ash cement permitted a great expansion of architectural methods, particularly the development of domes and vaults to cover large areas, of foundations, and of structures such as bridges and sewerage systems where water-proofing was essential.

=
**Pipes:** A hollow cylinder of metal, wood, or other material, used for the conveyance of water, gas, steam, petroleum, etc. A tube of wood, clay, hard rubber, or other material, with a small bowl at one end, used for smoking tobacco, opium, etc. =====

=
**Deck:** Any open platform suggesting an exposed deck of a ship. An open, unroofed porch or platform extending from a house or other building. Any level, tier, or vertical section, as of a structure or machine. =====

**What is the difference between tiltwall construction, tilt-up panel construction and pre-cast concrete construction?**
This terms (Tilt-up panel construction, tiltwall construction, precast concrete building construction) are used to reference new or nontraditional cement building processes. As previously stated in this article, tilt-up and tiltwall are two terms used to describe the same process. For a tilt-up concrete building, the walls are created by assembling forms and pouring large slabs of concrete called panels directly at the job site. The panels are then tilted up into position around the building's slab. Because the concrete tiltwall forms are assembled and poured directly at the job site, no transportation of panels is required. One major benefit of this is that the size of the panels is limited only by the needs of the building and the strength of the concrete panels themselves.

The difference between tilt-up and tilt-up walls, are that the tilt-up walls are poured outdoors, contractors are at the mercy of climatic conditions. When temperatures drop below freezing, curing the concrete panels becomes more difficult and expensive. This is why tilt-up construction is particularly popular in places where cold weather occurs less frequently.

The precast concrete building process is similar to tilt-up construction, but it addresses the challenges presented by weather. For precast concrete buildings, work crews do not set up forms at the job site to create the panels. Instead, workers pre cast concrete panels at a large manufacturing facility. Because the precast concrete forms are poured indoors, this activity can take place regardless the weather conditions. After curing, the precast concrete panels are trucked to the job site. From this point, precast concrete buildings are assembled in much the same manner as tiltwall buildings.