Watch these videos first!! on this link
http://www.youtube.com/user/j3553118r/videos
The type of technology from Construction that is featured here is the Bulldozer
The machine: bulldozer, is a crawler with a continuous track. It is equipped with a substantial metal plate, known as a blade, used to push large quantities of dirt, rocks, sand, etc., during construction work. The Bulldozer is most of the time equipped with a claw-like device at the rear (also known as a ripper). This ripper is used to loosen densely-compacted materials.
Here is a picture with all of the parts of the bulldozer labeled
Bulldozers are large and powerful tracked heavy equipment. These tracks give them amazing ground hold and stability through very rough terrain. Wide tracks help distribute the bulldozer's weight over a large area. This prevents it from sinking in sandy and muddy ground. The Caterpillar D9, for example, can easily tow tanks that weigh more than 70 tons. Because of these attributes, bulldozers are used to clear areas of obstacles, shrubbery, burnt vehicles, and remains of structures.
Sometimes a bulldozer is used to push or pull another piece of earthmoving equipment known as a "scraper". The towed Fresno Scraper, invented in 1883 by James Porteous, was the first design to enable this to be done economically, removing the soil from the cut and depositing it elsewhere on shallow ground (fill). Many dozer blades have a reinforced center section with this purpose in mind, and are called "bull blades."
The bulldozer's primary tools are the blade and the ripper
Blade
Ripper
Scrapper
Multi-shank ripper
Ripping rock lets the ground surface rock be broken into small rubble easy to handle and transport, which can then be removed so grading can take place. Agricultural ripping lets rocky or very hard earth (such as podzol hardpan) be broken up so otherwise unploughable land can be farmed. For example, much of the best land in the California wine country consists of old lava flows. With heavy bulldozers the lava is shattered, allowing agriculture. Also, hard earth can be ripped and broken up to allow planting of orchards where trees could not otherwise grow.
Other uses
Bulldozers are also used for military use. Some think why would they be used for the military but they are used I a very effective and efficient way. They can be used to push dirt up as a barricade or to get rubble of a road that needs to be used for instant use or to take down buildings that are in the way or need to be demolished. They can also prepare firing positions. Some of the parts of the bulldozer are also used on other military vehicles like: The dozer blades are fixed on combat engineering vehicles and can optionally be fitted on other vehicles, such as artillery tractors like the Type 73 or M8 Tractor. Dozer blades can also be mounted on main battle tanks, where it can be used to clear antitank obstacles, mines, and dig improvised shelters. Combat applications for dozer blades include clearing battlefield obstacles and preparing fire positions. 
History
The first bulldozers were adapted from a farm tractor called Holt. These tractors were used to plough the farm fields. The versatility of tractors in soft ground for logging and road building contributed to the development of the armored tank in World War I.In 1923, farmer James Cummings and draftsman named J. Earl McLeod made the first designs for a bulldozer. By the 1920s, tracked vehicles became common, particularly the Caterpillar 60. To dig canals, raise earth dams, and do other earth moving jobs, these tractors were equipped with a large thick metal plate in front. There are three main types of bulldozer blades: a U-blade for pushing and carrying dirt relatively long distances, a straight blade for "knocking down" and spreading piles of dirt, and a brush rake for removing brush and roots. These attachments (home-built or built by small equipment manufacturers of attachments for wheeled and crawler tractors and trucks) appeared by 1929. Widespread acceptance of the bull-grader does not seem to appear before the mid-1930s. The addition of power down-force provided by hydraulic cylinders instead of just the weight of the blade made them the preferred excavation machine for large and small contractors alike by the 1940s, by which time the term "bulldozer" referred to the entire machine and not just the attachment.
Over the years, bulldozers got bigger and more powerful in response to the demand for equipment suited for ever larger earth work. Bulldozers grew more sophisticated as time passed. Important improvements include drive trains analogous to (in automobiles) an automatic transmission instead of a manual transmission, blades controlled by hydraulic cylinders instead of early models' cable winch/brake, and automatic grade control. Hydraulic cylinders enabled more precise manipulation of the blade and automated controls.
Future
I think that the future for this bulldozer is a more effitient and more powerfull bulldozer that can push more and take more down. The companies that build these magnificent machines will be forever in buisness because of thier brilliance in their making of the bulldozer.
