Terrorist Target Civil Engineering Structures Worldwide

Terrorist expose themselves or express some demands worldwide through terrorist attacks on building structure, indicating civil engineering structures one of the most desired target. The terrorist often target at hotel, restaurants, and on public transportation or places where civilian has gathered .The attack is highlighted by several recent terrorist attack such as on Moscow Metro Train (2010), Marriott Hotel in Jakarta (2009), and Mumbai (2008) and most notorious twin tower and pentagon attack (2001)  which had shown that the destruction of the hotels and other facilities such as public transport and military base has become target of the terrorist. As a result there is a need to increases the resistance of the building materials against explosive loading especially critical government, military and corporate buildings, strategic bridges, dams and also chemical or petroleum plants that are all at risk from terrorist attack.

September 11 Pentagon attacks

Pentagon  attacks: On September 11, 2001, exactly 60 years after the building's groundbreaking, hijacked American Airlines Flight 77- a Boeing 757-223 was crashed into the western side of the Pentagon, killing 189 people, including five hijackers, 59 others aboard the plane, and 125 working in the building.

Mumbai attacks: The 2008 Mumbai attacks were more than 10 coordinated shooting and bombing attacks across Mumbai, India's largest city, by Islamist attackers who invaded from Pakistani seawaters. The attackers received reconnaissance assistance before the attacks, and when later captured stated that the attacks were conducted with the support of Pakistan's secret service, the. The attacks, which drew widespread global condemnation, began on Wednesday, 26 November and lasted until Saturday, 29 November 2008, killing 164 people and wounding at least 308.

2008 Mumbai attacks

Moscow Metro bombings: The 2010 Moscow Metro bombings were suicide bombings carried out by two women during the morningrush hour of March 29, 2010, at two stations of the Moscow Metro (Lubyanka and Park Kultury), with roughly 40 minutes interval between. At least 40 people were killed, and over 100 injured.

2010 Moscow Metro bombings

Twin Tower attacks: Hijacked American Airlines Flight 11 and United Airlines Flight 175 intentionally crashed into twin tower resulting two massive 110-story towers to fail killing near 3000 people.

September 11 Twin Tower attacks

Most of the building materials is made of concrete which brittle and has low tensile strength. As a result concrete members exposed to explosive could not support such loads and stresses that usually take place on concrete beams and slabs and will result in collapse of the structure, or severe cracking as well as fragmentation. The design and construction of new structure and strenghting of existing structure which are vulnerable to explosive, blast, airplane or missile attack will be discussed in later post.

Read: What Structural System Perform Best against Explosion?

What Structural System Perform Best against Explosion?

In the wake of the Sept. 11, 2001 terrorist attacks in the U.S., safety to all buildings in regard of design and construction continue to be in great demand. Blast resistant concrete buildings subjected to external blast pressures are generally shear wall structures rather than rigid frame structures. Shear wall structures respond to lateral loads in a somewhat different manner than rigid frame structures; the basic difference being the manner in which the lateral loads are transferred to the foundation. In rigid frame structures the lateral loads are transmitted to the foundation through bending of the columns. In shear wall structures, the lateral forces are transmitted to the foundation through both bending and shearing action of the shear walls. Shear walls are inherently strong and will resist large lateral forces. Consequently, shear wall structures are inherently capable of resisting blast loads and can be designed to resist substantially large blast loads whereas rigid frame structures cannot be economically designed to resist significant blast loads. 

Exterior Shear Wall Construction

In shear wall structures, beams and columns are usually provided between shear walls to carry the vertical loads including blast loads on the roof and not to transmit lateral loads to the foundation. For example, blast loads applied to the front wall of a two-story shear wall structure are transmitted through the roof and intermediate floor slabs to the shear walls (perpendicular walls) and thus to the foundation. The front wall spans vertically between the foundation, the floor, and the roof slab. The upper floor and roof slabs act as deep beams, and, in turn, transmit the front wall reactions to the shear walls. The roof and floor beams are not subjected to significant axial loads due to the diaphragm action of the slabs. The interior columns are usually not subjected to significant bending moments since there is no sidesway due to the extreme stiffness of the shear walls. However, significant moments can result from unsymmetrical loading conditions. Columns which are monolithic with the exterior walls may be required for severe load conditions. These exterior columns are subjected to both significant axial load and moment. The axial load results from the direct transfer of the roof and floor beam reactions while the moments are caused by the lateral blast load acting on the exterior wall.

Failure Modes and Damaged Classification of Concrete against Explosion Loading

Generally the failure modes on structure associates with the explosive loading can be flexure, direct shear or punching shear, bleaching and spalling which is depended on the explosive size and standoff distance between the blast source and the target as shown in Figure 2.

The extend of the damaged on a structure can be classified as light, moderate and also severe.

In Fig-1 the damages by explosion are marked as A,B,C respective to Severe, Moderate, Light. 

Fig -1 Concrete  Damaged by  Blast 

Light damaged (Fig: 1 C) is referring to the appearance of hair line crack with crack width of less than 1 mm on the exposed surface of the concrete. Moderate damaged (Fig: 1 B)refers to the situation when the bottom surface of the concrete is having cracks width of up to 1.5 mm and also having a minor spalling. Severe damage (Fig: 1 A)refers to the large cracks up to 4 mm wide together with large deflection and also heavy concrete spalling.

How does Reinforced Concrete Protect Nuclear Power Plants against Terrorist Attack?

After twin tower collapsed by terrorist attack, it is seriously studied that how nuclear power plants in United States are safe. In this post I shall discuss how the infrastructure of reactor itself and surrounding structures will response when a terrorist air plane or hijacked plane impacts the nuclear power plants. 

A nuclear power plant's containment structure, which encloses the nuclear reactor, is only a few dozen meters in diameter, very much smaller (and therefore difficult to aim at) than the WTC's towers, which represent a volume larger than a NPP's containment structure by a factor of 100 (at least).

A nuclear power plant's containment structure consists in a more or less 1 meter thick wall of very thick and heavy reinforced concrete : much more resistant than the windows and not-so-thick metallic structures of the WTC.

U S nuclear power plant

If the airplane hits other buildings on the site around it, other than the containment structure, the reactor will automatically stop due to the many independant and automatic security systems (even, in most cases, if the control room was destroyed).

If the airplane hits the side of the circular concrete containement structure (at an angle significantly less than 90°), it will probably just bounce off the side and hardly damage the external structure at all, because the containment structure in most power plants is very heavy, thick and strong and has a more or less circular form (reinforced concrete). 

If the airplane hits the top of the containment structure, it will probably not directly damage the vital structures of the core of the reactor which are, in most installations, located much lower, in the bottom part, or at middle height in the reactor building, and the reactor will stop automatically (the automatic protection against earth-quakes will be activated by the impact). 

If the airplane hits the containment structure in it's middle-height or lower part, which isn't easy because there are many other (non-nuclear) buildings around a nuclear power plant, it will the need to get through not only the very thick external containment, but also several successive reinforced concrete walls (about 20 to 40 centimeters thick each), on most nuclear power plants, before reaching the heart of the reactor itself. The probability that pieces of a large airplane make their way through all these successive walls isn't so certain.

Twin tower collapsed by terrorist attack

- terrorist attacks or plane accidents are in fact taken in consideration when designing nuclear power plants, but only to resist the crash of small airplanes. A large airplane at full speed as in the case of the WTC, may produce some damage to the containment structure and, perhaps, to the reactor itself. 

Thus if these following if’s are happened simultaneously: 

-if the plane doesn't miss the NPP 

-if it hits the concrete containment exactly on the middle, not on the sides 

-if it strikes the containment structure not too high and not too low 

-if it gets through the containment structure 

-if it damages both the (small in volume) core of the reactor or a vital part of the primary circuit), 

-if it also damages several or all the multiple redundant safety systems 

then a bad accident MAY perhaps happen. 

What were the Defects in World Trade Center Design?

The World Trade Center was in Lower Manhattan, New York City, United States which is also known as twin towers. The complex opened on April 4, 1973, and was destroyed in 2001 during the September 11 attacks. The site is being rebuilt with five new skyscrapers and a memorial to the casualties of the attacks. Of which, only one skyscraper has been completed with four more expected to be completed before 2020. While New skyscrapers are built in the site and others are pending to build or approved, it is a question the WTC was a faulty designed.

The answere of above question is the World Trade Center was not defectively designed. No designer of the WTC anticipated, nor should have anticipated, a 90,000 L Molotov cocktail on one of the building floors. Skyscrapers are designed to support themselves for three hours in a fire even if the sprinkler system fails to operate. This time should be long enough to evacuate the occupants. The WTC towers lasted for one to two hours—less than the design life, but only because the fire fuel load was so large. No normal office fires would fill 4,000 square meters of floor space in the seconds in which the WTC fire developed. Usually, the fire would take up to an hour to spread so uniformly across the width and breadth of the building. This was a very large and rapidly progressing fire (very high heat but not unusually high temperature).

TWIN TOWERS: SEPTEMBER 11TH, 2001 TRAGEDY

JIN MAO TOWER : A Magnitude 7 Earthquakes Resistant Structure

The Jin Mao Tower is an 88-story skyscraper on a 24 000 m² plot of land close to the Lujiazui metro station of the Pudong district of Shanghai.

The building employs an advanced structural engineering system which fortifies it against typhoon winds of up to 200 km/h (with the top swaying by a maximum of 75cm) and earthquakes of up to 7 on the Richter scale. The steel shafts have shear joints that act as shock absorbers to cushion the lateral forces imposed by winds and quakes, and the swimming pool on the 57th floor is said to act as a passive damper.

The 88 floors (93 if the spire floors are counted) are divided into 16 segments, each of which is 1/8th shorter than the 16-story base. The tower is built around an octagon-shaped concrete shear wall core surrounded by 8 exterior composite supercolumns and 8 exterior steel columns.Three sets of 8 two-story high outrigger trusses connect the columns to the core at six of the floors to provide additional support.

The foundations rest on 1,062 high-capacity steel piles driven 83.5m deep in the ground to compensate for poor upper-strata soil conditions.

At the time (2006) those were the longest steel piles ever used in a land-based building. The piles are capped by a 4m-thick concrete raft 19.6m underground. The basement's surrounding slurry wall is 1m thick, 36m high and 568m long, and composed of 20,500 m³ of reinforced concrete.

Historical development of Admixtures

Admixture is a material other than water, aggregates, hydraulic cement, and fiber reinforcement, used as an ingredient of a cementitious mixture to modify its freshly mixed, setting, or hardened properties and that is added to the batch before or during its mixing. 

Admixtures have long been recognized as important components of concrete used to improve its performance. The original use of admixtures in cementitious mixtures is not well documented. It is known that cement mixed with organic matter was applied as a surface coat for water resistance or tinting purposes. It would be a logical step to use such materials, which imparted desired qualities to the surface, as integral parts of the mixture. The use of natural admixtures in concrete was a logical progression. Materials used as admixtures included milk and lard by the Romans; eggs during the middle ages in Europe; polished glutinous rice paste, lacquer, tung oil, blackstrap molasses, and extracts from elm soaked in water and boiled bananas by the Chinese; and in Mesoamerica and Peru, cactus juice and latex from rubber plants. The Mayans also used bark extracts and other substances as set retarders to keep stucco workable for a long period of time.

Importance of Dispensers in Application of High-range Water-reducing Admixtures

Water/cement ratio is very important term in concrete technology as a optimum water content produced high strength than a W/C that are not specified from mix design considering aggregate grading, its moisture content and other conditions like environment ( very cold or hot weather). Some high-range water-reducing admixtures have a shortlived effect on the slump of concrete. Therefore, it is expected that these materials will be dispensed as close to placing time as possible. For ready-mix operations, this might mean the use of a truck-mounted dispenser in the form of a calibrated storage tank. The tank will be charged with the admixture at the same time the concrete is loaded. The user can request an increase in slump by injection of a HRWR admixture, and the driver will dispense the required amount into the turning drum. The volume dispensed will be recorded on the delivery ticket. The injection should be performed under pressure through a spray nozzle to thoroughly disperse the admixture into the drum. Field dispensers, consisting of a measuring unit and pump, can be used at the site.

Truck-mounted Dispenser of Admixture

It is incumbent on the concrete producer to take as great an interest in the admixture dispensing equipment as in the rest of the batch plant. Operating personnel should be trained in the proper operation, winterization, maintenance, and calibration of admixture dispensers. Spare parts should be retained as needed for immediate repairs. Regular cleaning and calibration of the systems should be performed by qualified internal personnel or by the admixture suppliers’ service representative. Admixtures have too powerful an influence on the quality of the concrete produced for their dispensing to be given cursory attention.

Pressure Control Damper from SGL

SGL Systems International manufactured a simple device designed to regulate the air volume through a section of duct. The dampers are designed to operate within the following environments, but not limited to:‐ 

a) High velocity systems. 

b) Saline and corrosive environments. 

c) Differential pressure of up to 20mbarg. 

d) Damper blades shall not extend beyond the damper casing 

Pressure control dampers are usually controlled by a modulating positioner in conjunction with a pneumatic or electric actuator. Automatic pressure-off dampers are normally controlled via a 4-20mA or 5-20VDC control signal, being connected to a status panel or HVAC Control Panel. The control of this damper is modulating and is infinitely positional. 

SafeDamp™ Type SFD 611/13dampers are supplied with single or multiple opposed blades. Maximum size for one blade is 1200mm wide by 450mm high. For widths greater than 1200mm a centre mullion is incorporated. For heights in excess of 450mm, multi-blades are incorporated being interconnected by mechanical linkages. These dampers are suitable for mounting and operation in any position with airflow from any direction and are supplied with straight edge termination flanges to suit Client interface.

Important features are: 

• Materials of Construction to suit application 

• All Welded construction 

• Standard 3mm thick casing 

• Stainless steel ¾” shafts 

• ¾” Oilite bearings 

• Damper depth to suit client requirements 

• Controls specification to suit Client 

• Low pressure drop 

• Lifting eyes incorporated 

• Earth Bosses standard 

• Suitable for high velocity systems 

• This damper is designed and manufactured  to close tolerances to minimise leakage  when the blades are in the closed position. Specific requirements regarding leakage can be addressed during project design with our engineers. 

• Electro‐pneumatic, electric or manual 

operation available

Piling operations

Pile is used where soil in shallow depth does not provide enough bearing reaction to support a heavily loaded pier, column or other member that transfer loads (moment, axial load or lateral thrust etc.). Bored pile is the customized forms of piling process which is adopted in the world as most reliable deep foundation with effecting surrounding foundation of neighbor structures. The major piling operations with figures are stated below (Figures are marked at lower left corner with corresponding steps): 

1. Auger fitted with appropriate head

 
2. Auger drilled into ground to required depth


3. Concrete poured down hollow core of auger whilst auger is removed

4. Steel reinforcement cage pushed into wet concrete

5. Wet concrete overspill at ground level

6. Ground level reduced and top section of pile 'broken down' to desired level

7. Pile cap or capping beam constructed

Piling Health Hazards

Pile is deep foundation. Like other deep foundation they are also used where soil in shallow depth does not provide enough bearing reaction to support a heavily loaded pier, column or other member that transfer loads(moment, axial load or lateral thrust etc.). Bored pile is the customized forms of piling process which is adopted in the world as most reliable deep foundation with effecting surrounding foundation of neighbor structures 

Piling health hazards 

There are many health (and safety) hazards during pile operations which are listed below:

1. Manual handling aspects to changing auger heads

2. Contaminated land hazards

3. Dermatitis and other cement-related hazards

4. Manual handling and injury risks in placing rebar cage along with cement-related hazards

5. Cement related and manual handling hazards (excess concrete typically removed by hand)

6. Major hand-arm and whole body vibration hazards (HAVS/WBVS), noise, dust and other manual handling hazards

7. Insitu concrete hazards (many and various) 

Most of these hazards are prevalent in many construction operations and as such are not remarkable to those experienced in construction – more worryingly they are frequently just accepted as the norm. Among these breaking down of the pile top is considered as the most hazardous operation in terms of occupational health.

Concrete Slab Foundation for Shed

Like your house, a wooden storage shed must sit on a foundation. Of the two most common types of foundations, that being the concrete slab and the wooden skid foundation, the slab is somewhat more elaborate. The concrete slab foundation for shed is also known as a slab-on-grade foundation. The slab foundation will be discussed in this article. 

The concrete slab, when used as the floor of a storage shed, will be 3 ½ to 4 ½ inches thick with a perimeter or footing of 8 to 12 inches thick. The depth of slab, the type of metal reinforcement, the amount and type of gravel used for the sub-base and also the type of moisture barrier used can vary depending on local building codes. Generally the entire slab foundation can be poured all at one time using a wood form. When used in cold weather climates slab-on-grade foundations can only be used for detached sheds. The foundation, because it sits above ground is susceptible to frost heave in cold weather. If the building was attached the frost heave could cause damage to the attached building. 

The concrete floor slab of the shed requires quite a bit of concrete so it is beneficial to have it delivered by cement truck to the backyard work site by a local ready-mix company. Most ready-mix companies have a one yard limit before they will deliver. Air-entrained concrete wears best for an exterior slab and the ready-mix company will mix it for you if you inform them of how it is being used. If you are pouring a smaller slab you can rent a concrete trailer from a rental store or landscaping company. The concrete trailer is towed by car or truck with one yard of cement already mixed and you pour it yourself. 

Finishing a large slab can be quite tricky if you have not worked with concrete before so you may require some assistance with the pour. 

The required tools for laying a concrete slab foundation are: 

1. Circular Saw 
2. Drill 
3. Mason Line 
4. Sledge Hammer 
5. Line Level 
6. Framing Square 
7. Shovel 
8. Wheelbarrow 
9. Rented Plate Compactor 
10. Bolt Cutters 
11. Bull Float 
12. Hand Held Concrete Float 
13. Concrete Edger

Earthquake Zone Map of India

Earthquake Zone Map of India

Enlarge This Map

Foundation Drain System

Most homes built today have foundation drains to drain the water gathered around the bottom of the foundation away from the foundation to prevent it from leaking into the basement. The term foundation drain is frequently referred to as a French drain as they operate on the same principle, a ditch filled with gravel or stones that will provide a path for water to be diverted. Most basements that have water leakage problems are associated with the drainage system. The typical problems associated with drainage systems are that they are inadequate or the drainage system becomes clogged at the outlet.

The foundation drainage systems in modern construction consists of four inch perforated PVC pipe that is placed at the bottom of the foundation and covered with stone and fabric to catch the water and divert it around the house to a storm sewer or disposal area. 

The slope of the drainage pipe and outlet must be sloped downward to insure that the water runs away from the foundation. Although there are several techniques to installing foundation drains they all are designed to divert the water away from the foundation to keep the inside of the basement dry.

Appropriate backfilling and grading around the foundation is critical to for the system to work properly. The foundation backfill material should be either sand or gravel to allow the water coming of the house to drain down the foundation wall to the drainage system. In addition, the ground surface must be sloped away from the house so as much water as possible will run away from the house. The recommend slope of the finished grade is a 10 degree slope away from the house for approximately twenty feet from the foundation.

 If the water is not drained away it will build up until there is sufficient hydrostatic pressure (water pressure) to force the water under the footing and up into the basement along the floor outer seems.

It is absolutely critical to check the drainage system outlet periodically to insure that it is not clogged. If the system becomes clogged the water will backup in the drainage system and around the foundation and eventually leak into the basement. If you have a foundation drainage system installed and water appears in your basement it is most probably caused by the drain system outlet being clogged. Removing the clog will immediately remedy the problem.

Underpinning

It stands to reason that when it comes to building work you need to make sure everything is done correctly. It is common sense that you want everything to be to a high standard especially from a safety point of view.

Underpinning is a large part of this. Underpinning works in such a way that it helps to strengthen an existing building. There can be any number of reasons that a building's foundation becomes unstable however that doesn't mean that they have to stay that way. It is obvious that an unstable building is unsafe and so should be looked at immediately. Be contacting an expert building company to carry out underpinning for you, you can get your building back to its former state.

There can be any number of reasons underpinning is necessary. These include:

* The building itself becoming unstable through age and general wear and tear

* The building usage has changed which means it needs to be stronger

* The ground beneath it is becoming unstable through subsidence

* The soil in the ground has changed and is no longer strong enough

* The soil was never strong enough and was built incorrectly to start with.

* Rather than build a new building from scratch you want to build up an old one

* Buildings nearby going up, which has changed the property of the supporting soil

Underpinning is an important part of improving a buildings structure and so is something that should be taken seriously. You should also make sure that any work carried out is done so by a professional, reputable company. If you are unsure of a company to use then just a quick search online should help you find what you are looking for.

Underpinning is great because it means that you can use a buildings existing structure to build up. This can save you both time and money on your building project, essential if you have a budget that you need to stick too.

When hiring a company for any type of building work make sure you get a completion date from them before you let them commence work so that you can time the rest of your work schedule around it.

Insurance for Underpinned Houses

A lot of not so good commentary are made regarding houses that went through reinforcement. In fact, there are whole forums that can be found on the internet that discuss about the topic of underpinned houses and everything that involves those houses. See, these houses seem to have gotten a bad rep and not without basis of course. But contrary to common notion, these houses are completely okay but because they have been underpinned, they are difficult to sell and what's more, acquiring an underpinned house insurance can be difficult for the owner.

You can ask an underpinned house owner and for sure, you will hear tragic testimonies regarding their property insurance. These type of houses or structures are challenging to sell and obtain an insurance because they are marked as hazardous and you have to understand that no insurance company would be willing to cover a property that will potentially stash money from them in the future. This can be also the same reason why underpinned houses are so difficult to sell in the market. 

If you are contemplating about investing in an underpinned house or if you are presently keeping one, it would be worthwhile for you to take a look at insurance companies that are willing to offer underpinned property insurance to homeowners and would-be owners like you. The insurance company will request for the builder's note regarding your house and the reason why it was reconstructed together with the actions applied to solve the problem.

This is one of the ways for the insurance company to determine if the property is eligible for underpinned house insurance because if they see that the house still requires more improvement, they will not think about insuring it. Once the dangers have been assessed individually, that is when they will provide you the estimate for the insurance that you need or that may be the time when they will tell you that your house is simply too unstable for them to give it insurance. In that case, you can consider to have your house fixed to avoid its condition to get worse and for you to totally lose a house. These are just some of the things you must bear in mind if you are thinking about getting an underpinned house or if you already own one.

Concrete for Prefabricated Bridge Elements and Systems

Concrete is a construction material which is formed due to cementitious action of cementitious materials (like cement,slag cement etc.) with both coarse aggregate and fine aggregate in presence of water and in some special cases, chemical admixtures. . Concrete is used to make pavements, pipe, architectural structures, foundations, motorways/roads, bridges/overpasses, parking structures, brick/block walls, footings for gates, fences and poles and even boats. Besides this regular construction approach concrete is now used in prefabricated elements like Bridge Elements and Systems. 

Concrete is a popular material for prefabrication and accelerated construction projects. The ability to build elements off site in virtually any shape makes this material a prime choice for designers. Common prefabricated concrete elements include beams and girders, full depth deck slabs, and pier caps. Several states have built entire bridges using precast concrete elements including pier columns, abutment stems, footings, and retaining walls. 

Concrete is also used for making connections between different prefabricated bridge elements. These connections often require the use of high early strength concrete to allow for accelerated construction processes. 

Durability is a major concern of bridge owners. The new generation of high performance concretes offer durability that far exceeds the performance of past concretes. Plant produced precast concrete also has the advantage of being constructed in a controlled environment with higher production and curing standards than normally found in the field. This benefit of accelerated construction projects is often overlooked by designers.

How to do underpinning in foundations

Underpinning is a method used to increase the foundation depth. This may be done in case a developer wants to add more storeys to a building. Also the foundation could be damaged by tree roots and thus this method used for correction. The adjacent construction may have foundations lower than the existing thus requiring to be lowered. If basements are constructed very near an existing building, the foundation may need to be changed. The reason is for stability of the existing house. Cracks may appear in a building up to the base thus needing a foundation remedy.

The underpinning in foundations may be undertaken and but supervised by an engineer. This works should follow instructions keenly for safety. Before any commencement, of work the area of operation should be hoarded. The works take from excavation to finishes approximately a month to complete.

The area to work on is measured and mapped out. The work should commence from the corners working inwards. This is done on load bearing walls only.

Foundations without any load bearing walls are exempted. The defects on these walls can be corrected using most simple methods.

 

The underpinning in foundations starts with excavations. This should be done under a strip footing. A length of one meter, a width of half a meter and depth of half a meter pit is dug. This is done in stages of two meters. This is distance between the pits. After the excavations, mass concrete is added to the cavity. Mixes are one part cement, three parts sand and six parts aggregates. Concrete is made to a good consistence and is poured into the cavity. Use form work on the edges. Use a rod bar ensuring that the cavity under the existing foundation is filled up.

 

After the underpinning concrete is placed in the cavity, its allowed to set for two days. The operation is repeated for the next bay. This continues until the required foundation is complete. Ensure that the concrete is cured thoroughly before loading it. The next thing is to break off the projecting foundation. Cut the concrete flush with the mass concrete surface. after this is completed for all the bays, soil is then back filled and compacted thoroughly. Watering with a hose is done for consolidation of the soil. This is done upon completion of the work.

Save Grief With Epoxy Flooring

When one speaks of flooring, whether it is in houses or buildings, concrete is simply the king. Unfortunately, is that although it is a one of the best materials to use, a number problems come with the use of concrete. Vast numbers of people people have found the one of the most effective methods to prevent a number of these problems is to utilise a penetrative concrete sealer.

Concrete floors have been known to split, get cracks, and accumulate stains with time creating an unsightly appearance of the floor. Although these problems are caused by a number of reasons, the the top cause is high foot traffic. This is what has forced many business men to pay particular attention to the type of flooring they use for their floor. As everyone knows, not only does a worn out concrete surface create an unsafe work space, customers or clients may be horrified and get shocked with how a business owner's office looks and might have second thoughts about pushing through with the transaction. 

 

One good way by which business and householders can maintain their cherished concrete from cracking up is with the help of epoxy flooring. Epoxy flooring is done by applying a layer of epoxy to the specific concrete surface in order to cover pore like holes and/or tiny cracks. What this does is prevent moisture and many other contamintants from seeping in to the treated concrete area, similar to how a penetrative cement floor sealer acts. Keep in mind that after moisture gets into the concrete area then that is the time when it would start to break down. However, there is a major differential between the two, however, is that epoxy flooring usually last longer than concrete sealers.

Usually, epoxy flooring is also said to be more beautiful to look at than penetrative concrete sealers because of its high gloss finish and fresh and clean look. You will have a new floor in just a few steps! Also, it is even possible to find oneself falling in love with your new look surface. This is often so much so that you might want to put down that silly idea of having carpet put down so that your office or your house would look that bit more professional or chic. If you feel that epoxy flooring is a bit smooth and may even cause cause people to slide, no need to to worry. Epoxy seamless flooring is slip resistant so if you put it on an area where people need to constantly move about, there is minimal possibility of mishaps happening. What this means is that, if you happen to be a restaurant owner, you can install epoxy flooring on accident prone areas which can often be the kitchen. Your employees don't have to be careful of their every step they take as they can go about their activities assured there is very minimal possibility of any of them falling or getting injured. Epoxy flooring is also known to help by way of sanitation since it is much easier to clean and, since tiny holes have been blocked, there is almost no risk of germs seeping in the area.

The price is not really a problem when it comes to epoxy flooring as you can find oftentimes they are priced lower than many concrete sealers. So, they have a price that's within your budget and a assurance that you don't have to worry about people slipping or accidents happening, how can you ask for more?

DIY Tiling Tips

DIY tiling is often thought of as quite a risky task, unless you are experienced at doing it. If it's your first time, the prospect of tiling your own home can be a somewhat daunting one. People choose tiles as a surface in their homes for a number of reasons, primarily that they provide a waterproof surface whilst being visually appealing. There are plenty of resources online to give you hints and tips with tiling, but it's really about getting stuck in and giving it a go. However, there are a few things you should know before you try to tile any surface.

Before you start anything, you need to make sure that you have the right tiles for the job. Consider what materials are best suited for your needs and what look will best suit your home. Once you've chosen your tiles, you need to come up with a detailed plan of how the tiles will be arranged. Depending on how you want your tiles to appear, the arrangement should normally be symmetrical and straight.

Planning ahead should help avoid any mishaps during the process. This will also enable you to calculate whether you have enough tiles for the job.

The surface you are going to tile must be prepared beforehand. Whether the surface is flat or upright, it needs to be even and straight. If you fail to achieve a flat surface, when it comes to the actual tiling it will be extremely difficult and the end result will be less than impressive. If you don't have the ability to re-plaster or re-skim the surface, you could always consider putting up new plasterboard.

The next step is to actually secure the tiles to your chosen surface. For this you will need a special adhesive and once this is totally dry you should use a grout to fill in the gaps between the tiles. Wipe away any excess grout with a damp cloth.

Undoubtedly, you will need to cut some of your tiles down to size in order for them to fit perfectly. There are various ways in which you could tackle this, the easiest being using a flat bed cutter. With this machine, you lay the tile on the bed and run the scriber over, making a perfectly straight score where required. Now you place the tile in the cutting jaw, pull the lever and the tile will cut with ease.

How to Locate a Plumber in Beverly Hills

When you are evaluating a plumber Beverly Hills, make sure that the plumber is correctly licensed. Furthermore, a plumber in Beverly Hills must have a liability insurance of at least $500,000. If the plumber is employing others to assist with work, they should also carry Worker's Compensation Insurance, just in case there is an injury while at work. Both liability insurance and worker's compensation insurance are guidelines that guard you, the home owner, from responsibility for damage to your home and injuries on the jobsite.

There are several types of plumbing technicians in Beverly Hills, as well as other cities throughout the United States. Some plumbers work exclusively on repair work for homeowners and commercial property owners. Other plumbers specialize in new construction or re-design work. When picking your plumber, make sure that the plumber focuses on the area that is crucial to you.

Several important questions you should ask your plumber in Beverly Hills consist of: What is the standard response period for a service call? Have you got a website? Are you a member of the Better Business Bureau? Are your specialists radio dispatched? Are your vans fully stocked? Can you provide references? It is wise to establish some kind of relationship with a plumber in Beverly Hills prior to seriously needing one for an emergency.

When searching for a plumber in Beverly Hills, make sure you ask your friends, family and neighbors for personal references. Real estate agents are also a good supply of recommendations since they often deal with home contractors. Most plumbers in Beverly Hills charge either on an hourly basis or by a flat rate basis. If your plumber charges by the hour, keep in mind that you may be paying extra for travel time or for locating specific parts needed. Either way, a plumber in Beverly Hills must be able to give you some sort of estimate in writing prior to beginning work at your house. Most local plumbers in Beverly Hills demand more for weekend or after hour service. 

Any plumber Beverly Hills will show you that they provide excellent services but only a few can in fact deliver what they have promised. It is vital to be wise when choosing the right plumber for the job. Make sure to employ only the best plumber Los Angeles CA you will find. Ask associates or check websites online.

Review of Deck Flooring Tiles

Using deck flooring tiles has grown to be identifiable to getting a fantastic garden layout and patio. If you're planning on building a deck or changing the design of your present patio, these tiles are the better choice as they possibly can be installed quickly and easily without the need to hurt your financial allowance. Not only are these tiles best for garden structures and patios, it's also beneficial on your balcony, garage as well as the restroom.

The snap wood tiles are simple to put together and take away, and makes it extremely easy to transfer or move them into a different design. These types of tiles are made of pure wood with side interlocking snaps that securely holds them together with a rubber base which allows them to keep permanently flat together without moving around. It's waterproof and making them wet will not stop its sturdiness. Deck flooring tiles also works the best for outdoor flooring of your walkway, porch and the outside part of your pool or tub.

History of Deck Flooring Tiles

Two of the well-known brands of deck flooring tiles are Vifah and Kontiki. The company enterprise of Vifah deck tiles has its early beginnings in 1995. Vifah is a reliable manufacturer of deck flooring tiles ever since then, supplying quality tiles at a very economical price. VIFA's head office is situated in New York while their warehouses are situated in New Jersey and California.

Kontiki, on the other hand, has also made its brand in the deck flooring tiles market. It has been developing flooring tiles for over a decade. Kontiki focuses on the employment of shorea wood that is specially grown in Southeast Asia and Northern India. It's because of shorea's strong hard wood that every tile is able to endure different weather conditions. Kontiki's deck tiles and planks comes in diverse shapes and designs. It is situated in British Columbia Canada with BuildDirect managing its customer care requirements.

Popular Deck Flooring Tiles Product Features and Benefits

The top attribute among all deck flooring tiles are that they are quite simple to set up and take off. You can easily transfer, rearrange and reuse them at your convenience. You are able to snap them in and then snap them out again later on. Getting them for your deck floor could be then later employed for your kitchen area, garage or any place in the property which you would like to highlight a wood finish, thereby gives you much savings during this process.