1. A deck system for building a bridge superstructure, the deck system having a plurality of support beams extending longitudinally along the length of the bridge, and erected at predetermined spaced locations across the width of the bridge to define a separation, the support beams each having a plurality of beam anchors secured to the support beams; screed adjustors provided in pairs for disposing on opposed lateral edges of the support beams; precast concrete slabs having a width for spanning said separation between the support beams, and being disposed end to end in abutting relationship, the slabs having a plurality of slab reinforcement bars disposed within the slabs at spaced intervals along the lengths of the slabs, the slab reinforcement bars having free extremities which protrude from the slabs on opposite lateral sides thereof to lie over said support beams, and a selected number of said slab reinforcement bars additionally having portions which extend upwardly above an operatively upper surface of the slabs at regular spaced intervals to define slab anchors for securing a concrete topping to be poured onto the precast concrete slabs; deck reinforcement bars for coupling the precast concrete slabs to the beam anchors; and ties for securing the deck reinforcement bars to the beam anchors and to free extremities of the slab reinforcement bars. 

2. A deck system according to claim 1 having a plurality of precast concrete slabs each having rectangular upper and lower faces defining a pair of long sides and a pair of short sides, the short sides being somewhat recessed to define a chamfer on forward and trailing edges extending between the support beams for the precast concrete slabs to abut one another when placed end to end and provide a flush upper surface to support a concrete topping. 

3. A deck system according to claim 1 having a plurality of precast concrete slabs each having parallel lateral edges, and forward and trailing edges for abutting on adjacent precast concrete slabs, a selected number of slabs having a forward edge which is inclined relative to a respective trailing edge and a selected number of slabs having a trailing edge which is inclined relative to a respective forward edge. 

4. A deck for a bridge superstructure having a plurality of support beams extending longitudinally along the length of the bridge, and erected at predetermined spaced locations across the width of the bridge to define a separation, the support beams each having a plurality of beam anchors secured to the support beams and screed adjustors disposed in pairs on opposed lateral edges of the support beams, the deck having: a plurality of precast concrete slabs disposed end to end with forward and trailing edges abutting one another along the length of the associated support beams, the precast concrete slabs having a width for spanning said separation between the support beams, the slabs having a plurality of slab reinforcement bars disposed within the slabs at spaced intervals along the lengths of the slabs, the slab reinforcement bars having free extremities which protrude from the slabs on opposite lateral sides thereof to lie over said support beams, and a selected number of said slab reinforcement bars additionally having portions which extend upwardly above an operatively upper surface of the slabs at regular spaced intervals to define slab anchors for securing a concrete topping formed in situ on the precast concrete slabs; deck reinforcement bars coupling the precast concrete slabs to the beam anchors; ties securing the deck reinforcement bars to the beam anchors and to free extremities of the slab reinforcement bars; and a concrete topping formed in situ on the precast concrete slabs. 

5. A deck according to claim 4 in which the precast concrete slabs have parallel lateral edges, a selected number of slabs having a forward edge which is inclined relative to a respective trailing edge and a selected number of slabs having a trailing edge which is inclined relative to a respective forward edge. 

Foundation Systems

Raft slabs are as the name suggests foundations that cover the whole surface area of the building in one continuous piece. They are often joined when the area is too large for a single pour, but the rebar though the construction joints keeps the slab working as a whole.

In general they work well with flat sites. When the land has a slope to it the formwork and the fill at the lower end can get a bit of a handful and so at some stage a decision has to be made between using a raft slab or a strip footing on a sloping site.

Raft slabs are very quick and easy to build and they can be completed with a minimum amount of disturbance to the site and when completed the site is clean and accessible for loading up materials for the next stage of the work.

The sketch above shows a section through a typical edge beam. A requirement of the building code where I live states that all habitable rooms must have their floor levels a minimum of 150mm above natural ground level. Further, the code states that rooms like bathrooms that contain a floor waste should have a floor level that is a minimum of 250mm above NGL. So in practice the slabs are nearly always 250 or higher than the highest part of the adjacent land.

At the same time the structural engineer likes to see the beams going into the ground a minimum amount so it can be seen that raft foundations can get very expensive in terms of the concrete quantities used.

Foundation Systems

PIER FOUNDATION
            similar to a deck built several feet above the ground. It is supported by pillars and posts or pilings.

PILE FOUNDATION
      may be: cast in place-concrete poured into ground
      cased- steel pipe in ground then filled
      uncased- cased concrete 'plug' placed & case removed
       micropiles- small diameter drilled & reinforced

Although those of us in the ready mix business would love nothing better than to sell more concrete, when it comes to pervious concrete we want to make sure that it is the proper material of choice and if so, how much of a job should use it.  Question number one should always be, what is the underlying soils percolation rate?  If it is at least ½ of rain per hour then pervious concrete is an ideal candidate.  If the perc rate is not quite what we would like it to be, chances are we can address that by creating a deeper recharge bed, in other words, build a deeper holding tank under the pavement.  If there is any concern about the ability of the soils to take the rain storm that the pavement is designed for, then a good belt and suspenders approach would be to run a perforated pipe halfway in the recharge bed to allow the system to take all of the rain it can and if need be, have an extra outlet rather than have the rain back up into the pervious pavement sections.  Studies have shown that even clay soils can now be used under properly designed pervious concrete pavements and with recent mix design improvements pervious concrete is now being used not only for parking lots and sidewalks but for alleyways and residential streets.

When designing a pervious pavement concrete can be very competitive with traditional asphalt designs, especially when we use regular concrete drive lanes and pervious concrete parking stalls.  If as a designer you can remove or reduce the number of catch basins, perimeter drains and other underground work, many times a pervious concrete system will be the most economical way to build not only an environmentally friendly but also a safer parking lot.

Bob Banka is President of Concrete Management Solutions and has been involved with the development of pervious concrete for over twenty years.   To learn more visit: 

Concrete constructions are not simple tasks for anyone including experts. There are many factors to consider and questions to ask even before construction. Questions like “how much cement should I buy”? Costs are really one of the factors one should closely monitor since its a limited resource. One should consider being updated on concrete slab pricing and concrete slab cost for minor and major constructions. A concrete slab calculator and cement calculator may just answer your questions.

Calculating concrete slab cost in construction is very important. Since estimating costs in any production or construction for any concrete structure is always required for proper planning and management purposes, therefore concrete slab cost calculations along with other concrete calculations are essential.

Calculating concrete slab costs and other expenses should ensure a proper budget line for the project thus eliminating unforeseen shortages, financial losses and unnecessary budget expansions.

You can calculate concrete slab cost for construction at concrete block calculators and other related programs found in websites. Websites that can assist you in calculating concrete slab cost are the following:

There are also other websites that can help you do calculations on concrete slab cost. In using concrete slab cost applications on website, you first need to know specific details of the construction such as length, height, thickness, and other essential variables. If these concrete slab cost applications prove to be much of a hassle and complicates your calculations more, it is advised that you seek expert opinion from certified engineers.

The Minar-e-Pakistan (Urdu: مينارِ پاكستان; Mīnār-ĕ Pākistān) is a tall concrete unique minaret in Iqbal Park in Lahore, Pakistan. It’s height is about 198.5 feet. The name can be translated as Minaret of Pakistan, Pakistan Tower or Pakistan Column. This is the site where in 1940, seven years before the formation of Pakistan, the Muslim League passed the Lahore Resolution now the Pakistan Resolution in which the need for a separate homeland for the Muslims from the Empire of India under foreign rule was originally recognised. The Minar-e-Pakistan was designed by Murad Khan, a Turkish architect. The base of the tower is raised approximately four metres from the ground. It rises up to approximately 13 metres, forming a sculpted, flower-like base. From this point it tapers as it rises. The base platform is shaped like a five-pointed star and it encloses crescent shaped pools. The overall height of the monument is approximately sixty metres. It is constructed of reinforced concrete, with the floors and walls rendered in stone and marble. Now it is officially recognized as the National Monument of Pakistan.

How House Construction Works - Foundations
by Marshall Brain

Basements, crawl spaces and slabs are the three main foundation systems used on houses. In wet and coastal areas, it is sometimes common to put houses up on posts as well.

Slab
The slab is probably the easiest foundation to build. It is a flat concrete pad poured directly on the ground. It takes very little site preparation, very little form work for the concrete and very little labor to create. It works well on level sites in warmer climates -- it has problems up north because the ground freezes in the winter and this freezing can shift the slab at worst and at least lead to cold floors in the winter. A cross-section of a typical slab looks like this:

Around the edge of the slab, the concrete forms a beam that is perhaps 2 feet deep. The rest of the slab is 4 or 6 inches thick. A 4- or 6-inch layer of gravel lies beneath the slab. A 4-millimeter sheet of plastic lies between the concrete and the gravel to keep moisture out. Embedded in the concrete is 6-inch by 6-inch wire mesh (shown by the dotted line in the slab) and steel reinforcing bars (shown by the white circles at the bottom of the beams). You will often hear this sort of foundation referred to as a "floating slab" -- it "floats" on the soil, with the deeper concrete around the edge holding it in place. In northern climates, the concrete around the edge has to extend deep enough to remain below the frost line in winter.

One thing about a slab is that the sewer pipe, and sometimes much of the electrical conduit, has to be put in place before the concrete is poured. The sewer pipes are actually embedded in the slab.

Basement
A house with a basement starts with a hole about 8 feet deep. At the bottom of the hole is a concrete slab, and then concrete or cinder-block walls form the outer walls of the basement. Actually, a basement is poured in three pieces in most cases: the "beams," then the walls, and then the slab inside the walls, like this:

This approach helps keep the basement waterproof. The L-shaped piece is a steel reinforcing bar to bind the beam and the wall together.

Crawl Space
A crawl space has several advantages over basements and slabs:

• It gets the house up off the ground (especially important in damp or termite-prone areas).
• It is a lot less expensive than a basement and comparable in price to a slab.
• Duct work and plumbing can run in the crawl space, meaning that they are easy to service and move over the lifetime of the house.

Most of the time, a crawl space is made of cinder block with a brick facing, as shown in the image on the right.
This is exactly how our sample house is put together. Here is how the finished foundation looks:

You might have noticed in the previous pictures that the concrete work for the crawl space was not done with much precision at all. One of the neat things that the mason (bricklayer) does is carefully adjust the height of the cinder blocks and bricks with mortar thickness so that the crawl-space walls end up exactly level all the way around.

One problem that arises in crawl spaces and basements is dampness. In order to keep water out, perforated pipe and gravel are used in a trench around the crawl space to route water away. The drainage system looks like this:

In a house with a basement, this same sort of drainage system is added along the bottom of the walls. The basement walls are then generally insulated with rigid foam board and then heavily waterproofed before dirt is backfilled against the walls.