Dealing With Ambient Conditions When Placing Concrete Toppings

What is usually done when a layer of concrete in a house, building or driveway gets worn out? Well according to concrete experts a concrete topping is placed, which is defined as the process of creating new layers of high-quality, high-strength concrete over the worn-out concrete layer. However, laying out concrete topping should also take into consideration the current weather conditions, because this may affect the new layer’s strength. Read more to find out.

Placing Concrete Toppings During Hot Weather

When placing premixed concrete toppings, construction experts stress that these toppings are often subject to certain practices and conditions depending on the weather conditions. For example, when the weather is very hot, a lot of emphasis is focused on reducing moisture loss from the placement, and properly managing concrete setting times.

The factors that contractors and concrete suppliers generally consider before placing concrete toppings are aplenty. These include construction planning, concrete mixture design, base slab conditioning and more. Perhaps the simplest procedure when placing concrete toppings during hot and humid conditions is by working in stages – from pre-placement to placement and post-placement (which is not only good for the concrete topping, but also for the workers who would otherwise be exposed to the sizzling temperatures!).

Placing Concrete Toppings During Chilly Weather Conditions

When placing concrete toppings during chilly (or even freezing) weather conditions, greater importance is stressed on the need to prevent early freezing, as well as in managing temperatures during the curing process to enhance the strength development of concrete.

Most construction experts say that the concrete base slab must be maintained at temperatures of at least 40 F during the placement and curing process to prevent early freezing and to enhance strength. And if possible, the experts stress that it would be best to heat the base slab if only to prevent freezing, as well as lead to improved curing conditions.

And, when placing concrete toppings during freezing conditions, keep in mind your Boy Scout motto when you were a kid (or when your contractor was a kid), and that’s “Failing to be prepared is preparing for failure!

This means that you must never place concrete on frozen ground or onto snow or ice, as the frozen surface may settle when it thaws and therefore crack the concrete. When the ground is very cold, the concrete will absorb the coldness and set more slowly.

Placing Concrete Toppings During Rainy Weather

Perhaps the toughest weather to place concrete toppings would be during rainy, stormy conditions. The good thing is that under most circumstances, concrete toppings that are exposed to rainwater are not automatically damaged, especially if excess rainwater is removed before finishing.

According to guidelines published by Cement Concrete & Aggregates Australia, if the concrete surface appears or looks wet, the excess rainwater may need to be removed, if only to allow for the finishing process to continue. This is because the additional rain may increase the water-cement ratio, which could result in a weaker surface, lower strength and increased shrinkage.

And, before you schedule any concrete delivery during rainy weather, prepare a lot of plastic covering so you could place it over the freshly-topped concrete to protect it from the elements!

Understanding Slump

Have you ever observed how workers construct roads, or how they build flooring inside a home or apartment unit? Well, for the uninformed, the material commonly used for road surfaces and interior flooring is made up of concrete, which is generally composed of a mix of water, sand, cement and gravel. More advanced concrete mixes include stuff like chemical additives, plastics and fibers. The mixture proportion determines the properties of concrete (and this includes something called the “slump”). Read on to further understand what slump is all about.

What Does Slump Mean?

When I talk about slump, I am absolutely not referring to a sudden, severe or prolonged fall in stock prices on Wall Street. I am also not talking about an economic recession. Instead, I’m referring to something that deals with the quality of concrete.

According to seasoned concrete suppliers in my city, slump is defined as the measurement of the consistency or durability of concrete. In much simpler terms, this measures how easy or hard it is to push, mold and smooth out concrete.

Concrete’s slump rating denotes what construction application the concrete is appropriate for, as the higher the slump, the more “workable” would the concrete be. If the slump is low, then the concrete will not easily shape. And, if the slump is so high, then the concrete may become unusable because the gravel, sand and cement may settle out of the mixture.

How a Concrete Slump Test is Done

Once the concrete delivery truck arrives at your project site, the workers are not going to start pouring it yet, but what they’ll instead do is perform a series of tests, and one of that includes a concrete slump test.

According to civil engineering experts, a concrete slump test is often utilized to find out the appropriate water content in a batch of premixed concrete . Slump also determiens the distance (which is measured in inches) the concrete settles after removing a tool called the slump cone.

A concrete batch or mix that shows a high slump indicates that the batch has too much water in it, and would possibly be weak once it is fully cure.  The ideal concrete mix would be something that’s not too soft or stiff.

If contractors are working in very hot or very dry weather conditions, of if the mold has more intricate or complex shapes, then they may want to have a slightly wetter mix. Perhaps all contractors will tell you that if there’s more water in the concrete mix, the higher will be the risk of cracking. Mixes that are too dry will also be quite tough to pour and vibrate.

Doing a slump test gives contractors a good idea of what the proper mix should feel like. If you’re longing to do things the DIY way, perhaps you should get some training and guidance from professional contractors or construction workers, so that you’ll slowly gain the skills required to do a proper concrete slump test!

Finally, here’s a word of caution from construction experts – never use slump level to compare the quality of one concrete mixture to another. Instead, one should only utilize it to compare the quality of various batches of the same mixture!

How to Lay a Slab Correctly

Do you know the material that’s commonly used as flooring in most homes or buildings? (as well as in roads?) Nope it isn’t wood (although floors made of wood definitely have that classic old-world feel), but it’s something called a concrete “slab”! According to one of my preferred concrete suppliers in town, a concrete slab is a popular structural material or element of modern homes and buildings, which consists of a flat, horizontal surface composed of cast concrete. Read on to find out how to lay slab correctly.

Site Preparation & Creating a Strong, Level Foundation

The first step in laying out concrete slab would be to ensure the site is properly assessed and prepared. As a slab is often several inches thick, and is supported by columns, beams, walls or ground. The site should also be prepared to ensure the strength of the foundation where the slab is laid.

If you’re laying slab on a patio, driveway or the house’s interior, you may require a permit from the local building department or council (depending on where you live). It’s also worth checking whether there are any pipes or water mains running beneath the area that you wish to concrete.

Your contractor will then position stakes on the areas where the slab will be laid, as well as use a line level and some string to determine how the ground slopes. In order to level the soil, the workers could dig into the higher side of the slope, add a retaining wall to hold the soil in place, or move soil into the lower end.

When laying slab, it would be best to know the soil in the area you wish to concrete, because if you’re building on clay or loam soil, you may need to make room for around 6-8 inches of compacted gravel to be inserted or placed under the concrete. If you’re building on sandy soil, what’s nice is that sandy soil does not increase the risk of the slab cracking due to fluctuating water in the surrounding surface.

After doing all the essential site preparation stuff, your construction team chooses the boards. In general, for garages and sheds, 2 x 12 boards with five inch thick slabs are used, while for driveways 2 x 6 boards are utilized.

To ensure a strong foundation, the contractors will also make sure that the base is able to effectively drain, because water that’s not absorbed can often lead to cracks and improper movement within the concrete slabs. If the area to be worked on has sandy soil, the contractors may need not add a layer of gravel due to the sandy soil’s absorptive properties.

Reinforcing Slabs with Steel Bars, Pouring the Concrete and Applying a Smooth Finish

The next step would be to reinforce the slabs with steel bars to prevent cracking, and make the site more durable. I’d generally recommend that you hire professional premixed concrete contractors to do the job, because this can be labor-intensive and will require a lot of technical or engineering experience. Well, you can choose to supply the bars, which can be bought at almost any home center or hardware store (along with the tie wires and wire twisting tools to connect the bars).

Before preparing the concrete truck, consider the weather conditions too, as concrete dries much faster when the sun is out in full force. So, fi your contractor is pouring concrete in hot weather, they might be better off dividing the slab down the middle and filling the halves on another day, thereby spreading the workload (and focusing on one slab at a time).

If the site preparations and other more tedious tasks are properly done, the concrete forms should be square, level and have the capacity to withstand the pouring of concrete. Again, the pouring of concrete should be done on days where it’s not too hot or too cold, to prevent fast hardening or thawing.

Once the concrete delivery truck arrives, the workers will pour concrete into the furthest forms so it will have time to set, and they won’t need to move the truck back and forth. The workers can also pour concrete on a wheelbarrow for hassle-free transportation. Once the concrete is poured on the surface, a float is used to remove any imperfections left by edging or easing the bumps from the bull float. To gain a smoother finish, workers can follow the float with something called “trowelling”, which smoothens out other imperfections (although this should be done by a professional).

Concrete Surfaces – Polished Concrete

Could you name at least one of the most common construction materials used today? Well, if you’re still thinking of the answer, let me give you one item – concrete! Yes according to one of my favorite concrete suppliers,  concrete is defined as a material that is made up of both fine and coarse aggregates that are mixed or bonded together with water, cement and other additives (and cures over time).  Concrete can also be polished, of which we will talk about it in this article.  

Why Polished Concrete is Fast becoming the Flooring Material of Choice Today

For those who are looking to have durable, high-gloss flooring, polished concrete is fast becoming the flooring material of choice today. With the use of appropriate floor-grinding tools and equipment, contractors and workers can bring that classy, high-gloss and high-luster finish to new or old concrete surfaces.

Polished concrete is often used when building structures like hotels and restaurants (where a classy, high-luster finish is most desired), retail outlets, malls, showrooms, private homes, office buildings and other high-end residential developments.

What are the Perks of Polished Concrete?

Perhaps the main benefit of attaining a high-polished concrete appearance and look is that it adds a classy, decorative touch to the establishment’s interiors. The polished floors also add to the establishment’s aesthetic and overall value.

The other perks of polished concrete flooring include cost savings, as conventional floor coverings are not required when the slab is used as the finished floor surface. A polished floor will also not be as prone to damage as compared to using other materials, and will not need replacing for years to come.

Polished concrete floors are also quite easy to clean and maintain, as they will not easily harbor or be pestered with dirt, dust, grime and allergens. These are also readily available in home depot stores in a wide assortment of colors and designs.

The commercial and retail perks are also aplenty. For example, polished premixed concrete  floors

fare well in high traffic areas like malls, hotels, restaurants, office buildings and residential homes.  They also afford a longer service life and require lesser upkeep, since they’re easy to clean (and only require the occasional damp mopping).

Polished concrete floors also do not require the use of messy, slippery coatings or waxes, thereby saving establishment owners the added labor costs. These are also resistant to marks caused by truck or forklift tires, as well as from stains brought forth by oil or chemical spills.

These types of flooring are also very resistant to moisture issues, as they enable the floor to breathe, and reduce all the issues which arise with using other flooring materials like tiles. And, for office buildings, malls, showrooms and high-end residential units, polished concrete floors offer higher light reflectivity too (and they also reduce the need to use artificial lighting).

But, can all concrete flooring be polished? Well, before you place a new order for new concrete delivery, remember that old and new floors can be polished with adequate preparation (and as long as the floor is structurally sound). This means that you save more money in the long run!