Weather conditions at a job site may not be the same as those specified by manufacturers in their manual. In fact, laboratory conditions in which concrete specimens are tested are usually done in an area suitable for producing the best results. Therefore, concrete should be placed in a secure area, especially in cold weather conditions.
This means the warehouse or enclosures must provide adequate precautions to avoid the negative impacts of low ambient temperatures. Based on guidelines released by the American Concrete Institute (ACI), the definition of cold weather concreting is when the average daily temperature falls below 10 degrees for more than 12 hours, as this could potentially lead to concrete freezing issues.
Protecting concrete during cold weather
During cold weather, it is essential to at heat one or more of the concrete materials, including the water and aggregates used in the mix. This will provide the appropriate concrete temperature before it is used on the job site.
Protection while the concrete is finished, placed, and consolidated
Exposure of concrete during cold weather will extend the time of crews on the site, especially concreters assigned on the finishing. That is why it is essential to use enclosures, windbreaks, and other supplementary heating tools. It is also recommended to adjust the concrete mixture during the setting time. So, cement content will be increased, or accelerating chemical admixture shall be used for maximum effect.
Also, windbreaks are relatively important at the construction site since they can protect the personnel from biting winds that may cause excessive evaporation and temperature drops. The common height used is six feet for most construction projects. However, windbreaks could also be shorter or taller depending on the anticipated ambient temperatures, wind velocities, humidity, and concrete placement temperatures.
Another protective gear to consider are heated enclosures since they are very effective in protecting concrete in cold weather, but they are usually more expensive than windbreaks. Most enclosures are made of canvas tarpaulins or polyethene.
Three types of heaters are used in cold weather concrete constructions, including indirect-fired, direct-fired, and hydronic systems. Indirect-fired heaters are commonly used on fresh concrete surfaces. Direct-fired heaters are suitable for concrete that has not been subjected to the exhaust directly.
However, caution should not be taken lightly to ensure that workers are not overexposed to carbon monoxide commonly used inside the enclosure. Hydronic systems are high-tech applications for preheating and thawing subgrades, but they are too large for an enclosure and are widely used in large warehouses.
Handling, transporting, and mixing concrete must be coordinated with finishing and placing operations. In fact, the timing must be perfect since it should not be deposited too rapidly on the surface, or the contractor will face several finishing issues. Therefore, it is important to only hire a qualified and experienced concreting contractor in Canberra.
If you are constructing concrete slabs, the concrete should be placed along the perimeter, with each batch piled against previously dispatched slabs. This will ensure that each concrete slab has cured according to industry standards.
In other types of construction, concrete should be placed in forms, then it must be consolidated after. This is because consolidation will compact fresh concrete so it can mould within and around the form. It will also eliminate honeycomb, stone pockets, and entrapped air.
Also, when concrete is vibrated, it will no longer aggregate particles that settle in the forms under the action of gravity, and the large entrapped air voids will no longer appear on the surface. This is the main reason why consolidation is essential since it will ensure that concrete is tightly placed.
For concrete that will be visible on patios, driveways, and various types of structures, finishing is a must. In fact, a concrete surface can be finished in several ways, depending on its intended application. Some of the options will include textures, colours, design, and patterns on the surface. Some surfaces may require a different approach like screeding and strike off to properly place elevation and contour. At the same time, other surfaces may need a floated, broomed, or trowelled finish.
Screeding is a common finishing method, and it is usually done to cut off excess concrete and bring the top surface to correct grade. Concreters also use the bull floating method to eliminate high and low spots and embed large aggregate particles after screeding.
Jointing is also required to eliminate random cracks and is usually done by inserting plastic strips, metal, wood, or preformed joint material into the unhardened concrete. After joining, the concrete must be floated with metal, wood, or a finishing machine with float blades. This will prevent any imperfections like voids and humps. It also compacts the mortar at the surface in preparation for further finishing activities.
However, trowelling should not be done on a surface that has not been floated recently because it is not an adequate finish procedure. Trowelling without floating may lead to imperfections and cracks on the concrete surface.
Lastly, brooming should be done on the surface of the concrete before it has thoroughly hardened since it will create a slip-resistant coating for safety reasons.
If you are planning on building a patio in your backyard, you may need to consider several important factors before beginning your project like finding the right location and some maintenance requirements that you need to fulfil once the structure is constructed.
In this article, we will share some of the things you need to decide upon before building your patio.
Finding the best location
If you have limited space in your backyard, you probably don’t have many options especially when it comes to location. However, when you have ample outdoor space, establishing the best location is important. For this purpose, it’s best to get in touch with a landscape designer since they can advise you on the best place for your patio. This will be an area ideal for entertainment and leisure activities.
How do you plan to use the patio?
For convenience, it is better to have a patio located closer to your house or some outdoor cooking facilities. This is ideal for parties and gatherings since you are close to your kitchen. However, if you want a place to lounge, it’s best to construct your patio near the garden. You may also want to add some amenities and furniture to your outdoor space like day beds, a fire pit, or concrete benches.
Is the site level?
It is also important to choose an area in your backyard that is level and not in a steep spot since this will help reduce the overall costs of building a patio. It must also have sufficient access since this will minimise additional outlay.
What materials to use?
Depending on the size of your outdoor space, you need to find the materials that will help create a more cohesive landscape. So, if you have a larger backyard, you have more flexibility when it comes to the materials of your patio, like using bricks on the floor surface, concrete on the outdoor fixtures, wood on the outer wall.
However, you must also consider the details of your surrounding landscape to create that visual connection that gives your patio a unique look and feel.
The size of your patio will all comes down to how you plan to use the space. So, if you plan to entertain a large crowd or just dine outside with your family, your patio will need a big area.
DIY or hire a professional contractor?
If you plan to build a patio yourself as a cheaper option, you need to prepare a lot of things and that will take time, money, and effort. However, that will also cut costs since you may be doing the heavy lifting on your own, which is possible if you have the skills and expertise to accomplish your project.
But suppose you don’t have the time, and you want a well-constructed patio based on your envisioned design. In that case, we encourage you to get in touch with a professional contractor since they have experience and expertise with these types of projects.
When your house is situated on a steep hill, you are likely to have an unobstructed view of the stars, vistas, and surrounding landscape. However, the major problem with this setup is realised when you are building a driveway from the road to your house. In fact, the road should accommodate all types of commercial and personal vehicles.
Here are some things to consider when you are building a driveway on a very steep hill:
It’s a must to have a large turning area that will provide ample space for large vehicles to manoeuvre through your driveway.
That is why you should get in touch with a contractor who knows how to mix gravel and concrete to get the best results for your driveway.