If you interested in tackleing a concrete project by your self or have ever wonder the steps involved in the basic construction of a new driveway, walkway or patio. Here are the four steps to required to complete a successful concrete project.
1st. You must prepare your site for the addition of new concrete material this consists of removal of old paved material weather that is asphalt or old concrete. If you currently have a gravel drive you can use those materials to form the base of your new concrete slab. The base materials whether gravel or sand should be compacted to form a firm surface for the concrete pour. In addition dont forget to slope your slab in appropriate direction away from your foundation to eliminate the possibility of water pooling around your foundation. Once you have accomplished these tasks for your new concrete project, your concrete project you can move onto the next step of forming of the concrete driveway, concrete walkway, or concrete patio.
Step2
Make your forms from wooden two by fours. Put the forms together with double-headed nails. Use stakes to secure the forms. The forms are set to grade by following a string line pulled from point A to B. The corners will be set where two string lines cross. From here, you can insure that the formwork is level. Once you have the concrete forms in place. Now is the time to calculate how much and what kind of concrete to order. Concrete is like cake batter it comes in a variety of different mixes with a variety of different applications. Feel free to work with one of our ready mixed concrete producers to help you decide what is the appropriate mix for your concrete project. But in general here is the low down on thickness and strenght you should consider for your concrete mix. For most instances a four inch concrete slab is appropriate for a concrete driveway or patio. In instances where you may have a lot of traffic on your concrete slab or heavy machinery you may want to consider going up to a depth of six inches for your concrete slab. For your information the thickness of federal interstates in most instances is 6" thick to support all of the truck traffic while an airport runway may be anywhere for 9 to 15 inches of concrete to support the stresses of aircraft departures and landings all depending on the amount of air traffic at the particular airport. The mix standards ready mix concrete producers use are all based on finished strength which means how much weight can be placed on the concrete slab per square inch. pound per square inch (psi) is the unit of measurement used to describe the compressive strength of concrete. The most desirable strength for driveways varies based on climatic conditions. In broad terms, the colder the climate the higher the desired psi. Areas which experience large numbers of freeze and thaw cycles also require a higher psi concrete mix design. The typical concrete strength used for a driveway is in the 2500psi to 4000psi range, although temperate areas of the country may use lower strengths. In addition to a higher psi for colder climates it is also recommeded to have your ready mixed concrete air entrained. Air entrainment helps protect concrete that will be exposed to freezing and thawing and deicers. An air entrainment admixture causes microscopic air bubbles to form throughout the concrete. These tiny bubbles function as relief valves when water in the concrete freezes, helping to prevent surface deterioration. The typical air entrainment for a driveway is in the five to seven percent range. Once you taken into account these issues. Your next step would be to figure out the volume required. Feel free to utilize our concrete calculator to figure how much concrete is required for your concrete project. the formula for calculating how much concrete you need is this- Length x Width x Thickness Divided by 27 this is assuming all your dimensions are in feet. with exception to the thickness. When ordering ready mixed concrete, should advise the producer of the intended use for the concrete. Quite often suppliers have standard mixes for specific applications. When the contractor specifies a particular strength level, the ready mixed concrete producer is responsible for proportioning and delivering a mixture that will yield the desired strength. It is always recommended to order 5 to 10 percent more than you have calculated for your project to address any variables. It is alot more expensive for the concrete delivery truck to come out a second time then paying for a little extra. Always give a couple of days notice of your concrete project so the concrete producer can schedule your concrete delivery appropriately.
When the concrete gets delivered to your jobsite be prepared. Time is money!! The ready mix producer has allotted x amount of time to your concrete delivery as they have in many instances scheduled multiple delivery for the concrete truck at your location. What does being prepared mean? Make sure all concrete forms are appropriately placed in positon for your concrete project. Make sure your have the proper amount of labor for your concrete project which usually means one person per 100 sq ft. and last but not least make sure you have the proper equipment ready for work which may include a wheelbarrel and or a concrete buggy, trowels a two by four to screed with and a darby or bullnose. So your concrete has arrived at your jobsite always confirm with the driver that you are receiving what you ordered. Once you have signed off on it it is yours. Once you have placed an ample amount of concrete with in a section of the forms your next step is to screed the concrete. Screeding the concrete is the process of using a straight flat edge to bring to level the concrete with the top of the forms. The secondary goal of screeding is to push the larger aggregate below the surface of the concrete. A two by four serves as a great inexpensive screed. Its length should span the width of your forms. Starting from one end drag your screed from one end to the other side of your slab. The next step in the concrete finishing process is to darby your concrete slab. A darby is flat tool used to smooth concrete flatwork immediately after screeding. This step can also be done using a bullfloat. A bullfloat would be used when a darby was too small for your slab. The purpose of using a bullfloat or a darby is to smooth out any parts of the slab as well as filling in aby voids in the concrete slab after the screeding step has been done. Two passes over the surface with the darby are enough. Overworking the concrete will draw too much cement and fine sand to the top and create a weak surface. The next step is to wait. What for what? You want to wait until the the water which has risen to the surface of the concrete slab as a result of the darbying step is reabsorbed by the concrete. Once the water has been reabsorbed you can continue with the concrete finishing process. Using the edging tool run the edger around the perimeter to round and compact the perimeter. Next divide the slab into equal parts with a straightedge and groover. Side-walks and small slabs need grooves about every 4 ft. Add grooves every 10 or 12 ft. on driveways and garage slabs. Dividing slabs with grooves looks nice, but the real reason is to control cracking. Drying and soil movement cause concrete to crack. The groove creates a weakened spot for the crack to form where it won’t be seen. Jointing is required to eliminate unsightly random cracks. Contraction joints are made with a hand groover or by inserting strips of plastic, wood, metal, or preformed joint material into the unhardened concrete. Sawcut joints can be made after the concrete is sufficiently hard or strong enough to prevent raveling. After the concrete has been jointed, it should be floated with a wood or metal hand float or with a finishing machine using float blades. This embeds aggregate particles just beneath the surface; removes slight imperfections, humps, and voids; and compacts the mortar at the surface in preparation for additional finishing operations. The next step in the concrete finishing process is to float and trowel the concrete slab.Floating removes the marks left by edging and brings the surface one step closer to a final finish. You may have to elbow grease on the float if the concrete is starting to harden If you’re happy with the look of your floated slab, you don’t need to do any more finishing. Repeat the edging and grooving steps after floating and after troweling to refine the groove and edges. If you are looking for a really smooth surface troweling should acheive this by passing back and forth over the concrete. In the event you are using air entrain concrete troweling is not recommended as it may result in blistering of the concrete slab. the next step which can be optional is brooming of the concrete slab. The purpose of brooming the concrete slab is to add additional texture to the finished concrete slab which serves for greater traction on the concrete. Timing is everything if concrete starts to pile up in front of the bristles as you drag the broom across, resmooth the broomed area with a float or trowel and then wait a little longer before trying again. After you are done with the concrete finishing process it is recommend to water down you concrete slab to slow down the curing process of the concrete. If the concrete cures to quickly it may crack. i still need the tools and what they do, adding stress cracks, mentioning admixture to the order step, and sealing the concrete.
Concrete also shrinks as it dries, so pouring too large an area will also cause problems down the road. If you install control joints properly, it will encourage the concrete to crack at the joints. The best way to install these is to cut lines in the slab of concrete at fifteen to twenty foot intervals. This allows the concrete to absorb the stress of vehicles driving over it. Corners are especially vulnerable. If you do have corners in the driveway, the control joint should radiate from the corner to the center of the slab.
| 
