Causes of Concrete Failure

Corrosion is not the only source of failure. Many other sources cause deterioration on reinforced concrete structures; this must be kept in mind and understood well when an inspection is undertaken. These sources of failure include:

• Unsuitable materials

• Unsound aggregate

• Reactive aggregate

• Contaminated aggregate

• Using the wrong type of cement

• Cement manufacturer error

• Wrong type of admixture

• Substandard admixture

• Contaminated admixture

• Organically contaminated water

• Chemically contaminated water

• Wrong kind of reinforcement

• Size error of steel bars

• Improper workmanship

• Faulty design

• Incorrect concrete mixture (low or high cement content and incorrect admixture dosage)

• Unstable formwork

• Misplaced reinforcement

• Error in handling and placing concrete (segregation, bad placing, and inadequate compacting)

• curing incomplete

• Environmental factors

• Soil alkali

• Seawater or sewage

• Acid industry

• freezing and thawing

• Structural factors

• Load exceeding design

• Accident as ballast load or dropped object

• Earthquake load

Concrete pour mishap in Brooklyn, N.Y., kills 1, injures 4 others

The collapse of a five-story building under construction in Brooklyn, N.Y., caused the death of a construction worker and injury to four others on Tuesday. Workers were pouring concrete onto Q-decking when the structure's third floor caved in. "We were able to determine that they were placing the concrete in the wrong sequence, and we believe that that is a major contributor to this collapse," said Department of Buildings Commissioner Robert LiMandri. "What we believe happened today was that they started from the top and worked their way down."

Civil Engineering Projects

A civil engineering project is a project which involves the construction and renovation of a structure or significant alteration in the environment. An example of a built civil engineering project might be a hydroelectric dam which is used to generate power which providing flood and irrigation control, while an environmental alteration might involve beach nourishment to protect a coastline.

While many people link the discipline of civil engineering with public works projects, civil engineering projects can also take place in the private sector, as when a firm constructs a major office tower or when a homeowner requests the services of an engineering company to repair damage caused by a natural disaster.

Civil engineering projects are taking place on a very diverse scale all over the world. Some examples of civil engineering projects include: updating a city’s sewage processing system to accommodate a growing population, building a canal, constructing a bridge, widening a roadway, wetlands restoration, and earthquake retrofitting of private homes so that they will meet local building codes. There are many disciplines within the very broad field of civil engineering, and projects also typically involve input from other experts as well as a civil engineer, with an engineering firm supervising the civil engineering project to ensure that it is done correctly.

The term “civil engineering” was coined to differentiate this very old branch of the field of engineering from the even older military engineering, which involved the application of math and science to military problems. Developing earthworks to serve as fortifications is an example of military engineering, for example, while creating earth walls to contain livestock falls under the purview of civil engineering. Some notable civil engineering projects such as the Great Pyramids, the Parthenon, and the Great Wall of China have lasted for thousands of years.

Civil engineering utilizes math and science to serve the human population in some way. Civil engineers are very concerned with the safety and efficiency of every civil engineering project, and they are also engaged in making projects which are designed to be lasting, which means that they must be flexible enough to accommodate changing usage needs in addition to being very sturdy and built to meet or exceed safety requirements.

A civil engineering project can involve starting from scratch to meet a need or solve a problem, as when civil engineers construct a wind farm which is used to generate renewable energy. It can also involve renovating, retrofitting, and updating existing projects to address changing uses and damage, in addition to correcting or fixing structures which were built with techniques now deemed outdated, or which failed due to faulty construction.

Tacoma Bridge Collapse

The Tacoma Narrows Bridge collapse in Tacoma, Washington in 1940.

(Photo Credit: University of Washington Libraries, Special Collections, uw21422)

Construction Specifications

Published By Construction Article On January 22nd 2011. Under Construction standards Tags: ASTM, Construction Specifications

Specifications of work quality are an important feature of facility designs. Specifications of required quality and components represent part of the necessary documentation to describe a facility. Typically, this documentation includes any special provisions of the facility design as well as references to generally accepted specifications to be used during construction.

General specifications of work quality are available in numerous fields and are issued in publications of organizations such as the American Society for Testing and Materials (ASTM), the American National Standards Institute (ANSI), or the Construction Specifications Institute (CSI). Distinct specifications are formalized for particular types of construction activities, such as welding standards issued by the American Welding Society, or for particular facility types, such as the Standard Specifications for Highway Bridges issued by the American Association of State Highway and Transportation Officials. These general specifications must be modified to reflect local conditions, policies, available materials, local regulations and other special circumstances.

Construction specifications normally consist of a series of instructions or prohibitions for specific operations. For example, the following passage illustrates a typical specification, in this case for excavation for structures:

Conform to elevations and dimensions shown on plan within a tolerance of plus or minus 0.10 foot, and extending a sufficient distance from footings and foundations to permit placing and removal of concrete formwork, installation of services, other construction, and for inspection. In excavating for footings and foundations, take care not to disturb bottom of excavation. Excavate by hand to final grade just before concrete reinforcement is placed. Trim bottoms to required lines and grades to leave solid base to receive concrete.

This set of specifications requires judgment in application since some items are not precisely specified. For example, excavation must extend a “sufficient” distance to permit inspection and other activities. Obviously, the term “sufficient” in this case may be subject to varying interpretations. In contrast, a specification that tolerances are within plus or minus a tenth of a foot is subject to direct measurement. However, specific requirements of the facility or characteristics of the site may make the standard tolerance of a tenth of a foot inappropriate. Writing specifications typically requires a trade-off between assuming reasonable behavior on the part of all the parties concerned in interpreting words such as “sufficient” versus the effort and possible inaccuracy in pre-specifying all operations.

In recent years, performance specifications have been developed for many construction operations. Rather than specifying the required construction process, these specifications refer to the required performance or quality of the finished facility. The exact method by which this performance is obtained is left to the construction contractor. For example, traditional specifications for asphalt pavement specified the composition of the asphalt material, the asphalt temperature during paving, and compacting procedures. In contrast, a performance specification for asphalt would detail the desired performance of the pavement with respect to impermeability, strength, etc. How the desired performance level was attained would be up to the paving contractor. In some cases, the payment for asphalt paving might increase with better quality of asphalt beyond some minimum level of performance.

ORTHOGRAPHIC VIEWS OF AN OBJECT BY FIRST ANGLE METHOD

Being the student of civil engineering we learn how to draw engineering drawings. The understanding of engineering drawing is required for a engineer since it is considered as the language of engineers, the above video help us to understand what a drawing reflects, it give a clear knowledge of object that is seen from the eye and the part of object hidden behind. Watching this will give u the better idea of what is been said here.

Change in attitude is the only path to success !

A life spent making mistakes is not only more honorable, but more useful than a life spent doing nothing.
George Bernard Shaw

The above concept is the real need of the time, especially the students who lacks the communication skills with their teachers in class due to shyness and hesitation, despite many teachers try to overcome it there are plenty of students in our university who spent their entire academic year without asking even one question from any teacher!

and the result comes out that they are then gossiping about poor performance of teacher instead of them which i think is a point of shame.

CIVIL ENGINEERING AT A GLANCE

Civil engineering encompasses the conception, design, construction, and management of structures, water supply facilities, and transportation systems and control of the environment for the maintenance and improvement of the quality of life. Civil engineering includes planning of small towns to the largest industries of the world.

Civil engineers play a major role in developing workable solutions to construct, renovate, repair, maintain, and upgrade infrastructure. The infrastructure includes roads, mass transit, railroads, bridges, airports, storage buildings, terminals, communication and control towers, water supply and treatment systems, storm water control systems, waste water collection, treatment and disposal systems, as well as recreational buildings, and ancillary structures for civil and civic needs. Without a well-maintained and functioning infrastructure, the urban area cannot stay healthy, grow, and prosper.

Some of the subsets that civil engineers can specialize in include photogrammetry, surveying, mapping, community and urban planning, and waste management and risk assessment. Various engineering areas that civil engineers can specialize in include geotechnical, construction, structural, environmental, water resources, and transportation engineering.

Civil engineering projects are actually systems requiring the skills and inputs of many diverse technical specialties,to create a master pieces like maga stuctures.

WHAT A CIVIL ENGINEER REALLY DOES...........!

Civil engineering is a wide-ranging profession, in which deferent nature

of work are handled like construction of roads, bridges, ports, and tunnels,

basic civic services i.e. water, gas and drainage are to be dealt with.

Civil engineers mostly work on the site to monitor technical and

administrative duties though civil engineers also set in their offices

but to inspect the working and test the standard of the material he has

to Be present on the site of working.

Roles of Civil And Military Engineer

Civil engineering is considered as the first main discipline of engineering, and the engineers were in fact truly military engineers with expertise in military and civil works. During the era of battles or operations, the engineers were engaged to assist the soldiers fighting in the battlefield by making catapults, towers, and other instruments used for fighting the enemy. However, during the peace time, they were concerned mainly with the civil activities such as building fortifications for defense, making bridges, canals etc

Read more: http://www.brighthub.com/engineering/civil/articles/41552.aspx#ixzz11p0izZoM