A.L. BLAIR

Concrete Curing 101

An In-Depth Look at the Concrete Curing Process

Concrete curing is an important and necessary part of any concrete project. How well you cure concrete will determine its final strength and quality.

Aside from the curing process, the strength of concrete is also dependent on its mix. So to make sure you have the proper strength of concrete for your project, consult with ready mix concrete companies.

Here’s a look at what concrete curing means and how you can do it properly to ensure you have a strong, durable, and lasting concrete for any concrete project, large or small.

What Is Concrete Curing?

Concrete curing is the process of keeping freshly poured concrete from drying out too quickly. Once poured, concrete requires adequate moisture, temperature, and time to cure properly.

Curing allows concrete enough moisture to gain strength over time. And it delays drying shrinkage until the concrete is strong enough to withstand shrinkage without cracking.

Why Is Curing So Important?

Without curing, concrete will dry out before a strong bond forms between all its ingredients. As concrete hardens, its water content rises to the surface.

If this water evaporates too quickly, it can cause both large and small cracks to develop in the concrete. It may also cause crazing—fine cracks that spider web across the concrete surface.

This results in a weaker concrete with a surface that won’t be strong enough to support the weight for its purpose—e.g. vehicles in a driveway, or patio furniture.

Concrete that doesn’t cure properly is also at risk of developing a weak, dusty, and crumbling surface, similar to chalk.

How Do You Cure Concrete?

You can cure concrete using several methods. But no matter the method you choose, make sure to leave the concrete forms in place to stop concrete from drying too quickly and to help with the curing process.

Water Curing

This method involves flooding, ponding, or misting concrete with water. It is considered the most effective curing method to prevent water from evaporating from the concrete mix too quickly.

To flood or pond water on concrete, form a dam wall of sand around the concrete formation, and use a hose to flood water on top.

A simpler way of water curing is to spray water onto the concrete slab with a hose or sprinklers.

Water Retaining

To retain moisture in concrete, you can use wet coverings such as sand, straw, canvas, or burlap. These materials must be kept wet during the curing process—e.g. with a sprinkler or a hose. If left to dry, they may aid in sucking out moisture from the concrete.

During high temperatures, you should cover concrete with wet burlap or a curing blanket and keep the cover constantly wet. This will prevent concrete from losing too much water from evaporation.

In colder temperatures, you can keep concrete warm with a burlap or straw covering. This will prevent the concrete’s water from freezing, expanding, and cracking the concrete.

Waterproof Paper or Plastic

These materials can be used once concrete is hard enough to resist surface damage. But plastic film can cause discolouration, so do not use it if the appearance of concrete is important.

You can also use a plastic sheet, held down with timber or cement blocks. Before placing any of these covers on the concrete, make sure to spray water on the concrete slab with a hose.

Curing Chemicals

If using curing chemicals, such as compounds or oils, you must apply these to concrete immediately after you finish the concrete.

Some compounds, like soluble waxy emulsions, can be sprayed onto concrete and left for weeks until they break down in the sunlight.

Note that some curing compounds may affect the adherence of resilient flooring, so speak with a concrete company before using these.

How Long Does It Take for A Concrete Slab to Cure?

At the very least, you should keep a concrete slab wet and warm—at temperatures between 10 and 32 degrees Celsius—for the first week. But ideally, you should let it cure for 28 days.

Concrete doesn’t reach its full potential strength until 28 days after pouring. So the longer you allow concrete to cure while keeping it wet, the harder and stronger it will become.

How Strong Is Cured Concrete?

The compressive strength of concrete is referred to as concrete cube strength or concrete cylinder strength and is measured in psi (pound-force per square inch).

The strength of cured concrete will depend on the type of mix you use. And this mix will depend on the type of concrete project.

If you’re pouring a concrete driveway, the mix should have a minimum compressive strength of 4000 psi to support the weight of vehicles.

As concrete cures, it gains strength. After 28 days, concrete gains 99 percent of its strength. And concrete may continue to gain the remainder of its strength for up to a year or two after.

You should keep heavy equipment off of concrete for the first 28 days while it’s strengthening. And you should definitely not walk on concrete for at least three days after pouring.

What’s the Difference Between Setting and Curing Concrete?

Concrete is set when it has hardened enough to support some pressure without being damaged—e.g. when you can walk on a concrete slab without leaving footprints.

Concrete is cured when it reaches its full strength. Once concrete is cured, it should be able to support the weight it was designed to support.

Depending on the conditions, concrete can set in less than two hours and up to 20 hours. Hotter temperatures speed up the setting time, while cold temperatures slow it down. And if it’s too cold—i.e. below freezing—concrete will not set.

Like curing, you can control the setting of concrete. Ready mix concrete suppliers can add chemicals (admixtures) to speed up or slow down the setting process, depending on the concrete project needs.

So if it’s cold out, accelerating admixtures will speed up the setting time. And retarding admixtures will slow down the setting time in hot weather.

The curing of concrete is an important process that cannot be overlooked during concrete projects. So make sure you use a proper curing method and for the right concrete curing time. Also order a strong enough concrete mix for your specific concrete project to get a durable, long-lasting finished product.

How Do Concrete Forms Work?

A Look at the Various Types of Concrete Forms and How They Help in Concrete Construction

Whether you’re building a concrete patio or a skyscraper, you’re going to need concrete forms to get the job done.

Without concrete forms, your concrete won’t hold its shape and will be at risk of cracking and losing its strength.

Concrete forms go hand-in-hand with other concrete placing techniques to ensure your concrete remains strong and durable.

So to guarantee your concrete construction projects go smoothly, order enough concrete products for the job and make sure you use concrete forms.

Here’s a look at how formwork is used, the principles behind it, and why it can be so helpful on the job site.

What Is Concrete Formwork?

Formwork, also known as concrete forms, is a temporary or permanent mould used to create concrete slabs and structures.

Concrete forms hold freshly poured concrete in place and the ideal shape until the concrete is strong enough to hold its own weight and shape.

To work effectively at supporting the concrete’s weight and shape, concrete forms must:

• Have tight joints so the wet concrete cannot leak through;
• Be rigid enough to prevent bowing under the weight of the concrete;
• Be strong enough to hold the concrete in place;
• Have proper horizontal and vertical support and bracing, such as with poles and stabilizers (also known as falsework);
• Be completely level; and,
• Be able to withstand the elements without warping.

With the proper construction and placement of concrete forms, you can ensure your finished concrete project will be the right shape with optimal strength and durability.

How Is Formwork Made?

Formwork is usually made from timber and plywood. But it can also be made from other materials, such as metals, ceramic, or glass fibre reinforced plastics.

Plywood formwork is also called shuttering. Shuttering is the most popular type of formwork and is created on site using water-resistant plywood and timber.

When on the job site, concrete contractors will erect plywood, steel, or aluminum formwork to create the moulds of concrete slabs, walls, and other structures.

Concrete formwork includes the following components:

Formwork Sheeting

The formwork that comes in direct contact with concrete is called the formwork sheeting, or the formwork shell. This sheeting will mould the shape of the concrete and have the most influence on the finished concrete surface.

Formwork Bearers

The formwork bearers, which are usually made of timber or steel beams and clamps, support the formwork sheeting. These distribute the concrete forces through the falsework, supporting structures, formwork ties, and soil.

Formwork Ties

Formwork ties are usually made of steel wire and are used to tie two formwork faces together to support horizontal pressure from vertical formwork.

The steel wire is slung around the formwork bearers, guided through boreholes in the formwork sheeting, and tightened by twisting the wire.

Once the formwork is constructed, concrete contractors will place rebar inside the formwork to reinforce the concrete.

Next, contractors will pour concrete inside the forms. Once the concrete hardens, they will remove (strip) the forms from the concrete structure if using temporary formwork.

To prevent damage to the concrete and difficulties when removing formwork, it’s important to consider the placement of formwork and the sequence in which you the framework will be stripped.

Avoid using too many nails and supports (falsework) when building formwork, as this will be too difficult to strip later on. Only use as much as necessary to maintain support of the formwork.

How Long Do You Leave Forms On Concrete?

Temporary concrete forms should be left to support the concrete until the concrete has thoroughly dried and reached an ideal strength to support its shape. This usually takes about two days after pouring the concrete.

If you remove the formwork too soon, the concrete might begin to sag, crack, and collapse. Remember to be patient and let your concrete thoroughly dry before removing formwork.

What Is Formwork Used For?

Formwork is used for holding the shape of concrete while it dries. It is commonly used for building concrete:

• Foundations,
• Walls,
• Ceilings,
• Beams,
• Columns,
• Paths,
• Walkways,
• Sidewalks,
• Driveways, and,
• Patios.

The type of formwork you use will depend on your project needs. A simple temporary plywood formwork, such as plank shuttering, is suitable for moulding concrete paths and driveways.

But if you’re building a concrete foundation for a home, you will want to use more sophisticated formwork, such permanent insulated concrete forms.

What Are Insulated Concrete Forms (ICF)?

Unlike traditional concrete forms, insulating concrete forms (ICF) are not removed once the concrete hardens. Instead, ICFs remain as permanent parts of the concrete structure.

While concrete creates the structure, the ICFs insulate the structure. Homes and buildings with ICF foundations are soundproof, airtight, and comfortable in all seasons. This insulation helps homeowners save on energy costs for heating and cooling throughout the year.

ICFs are often made from a combination of insulating materials, such as plastic foam beads and cement, or wood fibre and cement.

Another popular material for ICFs is expanded or extruded polystyrene. Expanded polystyrene is made by expanding plastic beads in a mould, similar to Styrofoam coffee cups.

Extruded polystyrene is made by expanding plastic resin and extruding through a die, similar to meat trays from grocery stores.

ICFs typically come in blocks or planks. ICF block systems are pre-formed with foam and metal or plastic ties. They are ready to stack and interlock when they arrive on site.

Plank ICFs are individual panels or planks of foam requiring assembly on site with ties.

Block ICFs save you time and labour costs, while plank ICFs save on shipping costs since they are more compact to ship.

These concrete forms usually provide at least two inches of insulation on both sides of a concrete wall.

ICFs are not only faster to place, but they also provide significantly better insulation compared to wood or steel frames. So if you’re planning to build a new home, consider using ICFs for a well-insulated foundation.

Cases Where Formwork Might Be Necessary

Formwork is necessary when there is no soil or other structural components to support freshly poured concrete and hold it in the desired shape.

Formwork is necessary for the construction of concrete and reinforced concrete structures, such as:

• Solid structures—e.g. foundations and columns;
• Reconstruction of structures;
• Structures with special functions—e.g. chimneys and containers;
• Bridges and towers;
• Public buildings; and,
• Structures with an irregular arrangement.

Vertical Formwork

Vertical formwork is necessary for building concrete foundations, walls, and columns. Tie wires or tie rods are also used with this formwork to support the lateral pressure of concrete.

Vertical formwork must also be anchored to the subsoil to prevent lifting from buoyant forces in the concrete.

Horizontal Formwork

Horizontal formwork is necessary for constructing concrete ceilings and beams. This formwork must be supported against vertical and horizontal loads, using formwork load-bearers and columns, braces and struts, or a rigid connection to existing structures, such as walls and columns.

Concrete forms are an essential part of building sound concrete structures. When constructed correctly, formwork moulds concrete into the desired shape and supports the weight of concrete while it’s drying.

And most importantly, concrete forms allow concrete to reach its optimal strength and durability without sagging or cracking.

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The Many Aesthetics of Decorative Concrete

Get More from Your Concrete Suppliers

When choosing home flooring upgrades, consider decorative concrete.

Decorative concrete takes the durability and reliability you expect from concrete and enhances these desired qualities with a rich aesthetic.

Aside from building construction projects, concrete has many uses for home décor.

Here’s a look at what decorative concrete is and how these concrete products from local concrete suppliers can enhance a home’s look and feel.

How Decorative Concrete Is Made

There are two common ways to make decorative concrete.

1. The most common method is to add colours to a concrete mixture. Then, once the concrete is placed, designs are stamped or hand-carved into the concrete to create a desired look or pattern.

A benefit of adding colour to the mix is that the tone is easy to control and is consistent throughout the mix.

2. Another way to make decorative concrete is to add colour with acid stains once the concrete slab has set. Acid stains create a marbled look on concrete since the colour is not uniform throughout the mix.

Lastly, decorative concrete must be sealed and finished. These last steps maintain the concrete’s quality and appearance by protecting it from moisture and stains.

Uses for Decorative Concrete

Decorative concrete is a versatile product that can be used all around your home from kitchen countertops, bathroom floors, and so much more. Here are some of the ways you can use decorative concrete to improve the aesthetic of your home.

Patios

You can expand your living space to the outdoors with a stamped concrete patio in your backyard. Stamped concrete makes for an attractive, easy to clean, and durable patio that can withstand the elements and support patio furniture.

Pool Decks & Seat Walls

Build a new pool deck or upgrade your existing deck with decorative concrete that will transform your backyard. Stain a pool deck that is already in good condition. Or, resurface with a concrete overlay that hides cracks, chips, and stains.

An overlay provides a surface for staining, stamping, or hand-carving designs like slate, flagstone, or cobblestone.

You can have durable faux grout lines that will never crumble and stones that will never lift or shift. And with many colours and design options, you can create a pool deck that suits your backyard theme.

Decorative concrete is ideal for pool decks since it is water resistant and won’t fade, chip, stain, or peel. It can also be skid resistant, so you can prevent slips and falls around the pool.

And seat walls made from vertical concrete resurfacing provide extra seating for your patio and pool area while adding a touch of style.

Porches & Walkways

A faux stone design, such as a flagstone porch and walkway, will boost your home’s curb appeal. You can also opt for the traditional wood porch look with a wood plank pattern that won’t splinter, need repainting, or develop water damage.

You can easily clean concrete porches and walkways with sweeping, hosing off, and dust mopping. And since the surface is durable and water-resistant, you can keep furniture and potted plants on your porch.

Bathrooms

Stained concrete flooring is ideal for use in bathrooms. This concrete can resist water, moisture, chipping, peeling, and fading. Sealed surfaces also resist mould, mildew, and bacteria growth.

Kitchens

Get your dream kitchen flooring with custom staining and stamping. Opt for the faux designer tiles, natural stone (e.g. cobblestone or slate), or wood planks.

Decorative concrete is realistic looking and more durable than the materials you replicate. You can wipe up spills easily, and the floors won’t stain, chip, splinter, or fade.

For grouted stone and tile patterns, you won’t have to worry about the grout staining, chipping, or discolouring.

Decorative concrete can also be used for backsplashes, replicating subway tiles, polished marble, limestone, and other beautiful stones.

Design Options and Enhancements

There are seemingly endless options for decorative concrete designs.

Whether stained, stamped, or hand-carved, concrete can look like wood floors, brick, marble, tile, granite, slate, and so much more.

You can even opt for custom illustrations, like your favourite team logo on the basement floor in your man cave.

So if you’re trying to weigh the benefits of stamped concrete vs interlock stone, remember:

You can have any design or natural stone appearance with concrete, and with all the added benefits of using concrete instead.

Caring for Decorative Concrete

There are a few steps you can take to maintain the quality and appearance of decorative concrete.

Use Entry Mats

Entry mats at doorways protect decorative concrete floors from dirt, debris, and damage.

Scraper entry mats outside of entryways pick up debris from shoes that could otherwise scratch or dull the concrete surface. And interior entry mats protect floors from dust and moisture.

But avoid using entry mats with rubber backing since these can cause hard-to-remove mineral deposits on the floor.

Use Furniture Pads

Furniture pads are a cheap and easy way to protect your floor from damage. Use felt pads and tap-in protectors to keep chairs, tables, and other furniture from scratching your decorative concrete.

Clean Regularly

When repeatedly walked on, tiny particles of dirt will wear down the finish of decorative concrete. So clean the floors regularly with dust mopping and damp mopping. And always clean up spills right away to prevent staining.

Use only clean water and/or a neutral cleaner when mopping. Do not use corrosive cleaners that will damage the finish, such as bleach, ammonia, vinegar, pine oils, and high phosphate cleaners.

Re-Finish

Decorative concrete finish is the top coat that protects the sealer and adds shine to the concrete. So to keep the floor protected, apply finish at least once a year. For high-traffic areas, you will likely need to apply a finish twice a year, or every three to nine months.

Polish

To keep your stained concrete floors looking new, you may wish to polish them every few years.

Avoid Using De-Icing Salts

De-icing salts can damage concrete porches, patios, and walkways by seeping in and causing concrete to expand with ice and crack. So to keep your outdoor decorative concrete in good condition, do not use de-icing salts in the winter. Use sand or cat litter instead.

Why You Should Consider Using Decorative Concrete

Decorative concrete is a beautiful option if you want to spruce up the appearance of your home floors or outdoor patio and decks.

Aside from looking great, here are some of the many reasons why you should consider using decorative concrete for your home:

Boost your home’s appearance with durable, customizable, and realistic looking decorative concrete. With many design options to choose from, you can transform your home and outdoor space to suit any style you desire.

Concrete Project Planning Basics You Need to Know

How to Keep Your Concrete Project On (Or Under) Budget

If you’re prepping for a DIY concrete project and aren’t entirely sure what to budget for, don’t worry—it’s not as complicated as it seems.

Planning, pricing, and prep all take a little bit of thought, but it’s not rocket science. When in doubt, you can always contact your local concrete supplier to get the lowdown on how it all works.

It’s important to note that concrete prices vary by type and location, so while there are no hard and fast rules, there are plenty of handy tips and rules of thumb that can help you keep your project on track, and even under budget.

Here’s what you need to know when budgeting for concrete products, as well as tips to help your project stay on-track!

Concrete Budgeting Basics

Make a List of What You’ll Need

Include everything you will need to complete your concrete project. This includes raw materials, tools, equipment, and safety gear.

Once you’ve completed the list, research the costs for each item. To find the best prices, compare prices online and ask for estimates.

If the costs are too high for your budget, consider making adjustments to your project. There are many variables to consider and adjust when calculating the total cost of concrete projects.

Variables to Consider

Size

The size of the area you plan to fill with concrete will determine how much concrete you need.

This could be a large concrete driveway, a basement floor, or a small patio in the backyard. There are no size limitations when it comes to concrete projects.

Type

There are different types of concrete mixes available depending on your preference and project needs.

If you want decorative concrete, this mix will need colour. And it may also need a slow drying time to properly stamp the concrete, so an admixture is necessary.

Admixtures

Your concrete supplier will have various admixtures to add to your concrete mix depending on your project type.

Admixtures can either speed up or slow down the concrete drying process. They can also help concrete withstand the free-thaw cycle and improve workability if you need to move the concrete around once it’s poured.

Shape

Rectangular and square concrete slabs are generally easier and cheaper to pour. Round concrete areas take more time and expertise.

Colour

If you want decorative concrete, you will have to decide on a colour (or colours) to use. Colours will cost more to add compared to plain concrete mixes.

You can either add colour during the mixing process or use chemical washes and sprinkle powders on top after the finishing stage is complete.

Stamps

Whether you choose to stamp the decorative concrete yourself or hire a professional, do expect to pay more for this added detail.

If you don’t hire the pros, you will either have to rent or buy the stamping equipment. Stamping concrete gives the appearance of brick, stone, or tile.

Delivery

If you order ready mix concrete from a local concrete supplier, it will need to be delivered to your home or project site. You may also wish to have the concrete poured professionally at the time of delivery.

Delivery and professional pouring are recommended, especially for large amounts of concrete. The concrete supplier can pour the concrete evenly in one go. This will allow for a consistent drying time and maintain structural integrity.

Mixing

Ready mix concrete from a local supplier will arrive onsite already mixed. But if you choose to buy bags of concrete, you will have to mix it yourself. This can save you some money, but it will take more time.

Sand or Gravel

Concrete slabs need a sub-base for support. This often consists of one or two layers of crushed stone of various sizes.

Depending on your project, you can use sand and/or gravel as sub-bases. These layers, like the soil base, will need to be compacted before pouring the concrete.

Equipment You’ll Need

Land Grading Equipment

Land grading refers to creating a gentle slope that will carry rainwater away from the concrete slab.

This ensures that water won’t build up and soften or degrade the soil underneath, which can cause concrete to crack. It also prevents flooding.

You can either rent this equipment or hire a professional who has their own land grading machinery.

Soil Compaction Equipment

Compacting the soil base before pouring the concrete will prevent cracks from forming in the concrete. You can rent this equipment from your local home renovation store, or hire a pro.

Compaction Vibrators

Concrete compaction ensures a smooth concrete surface and optimal density and strength. Consider renting concrete vibrators to compact your concrete.

Concrete Forms

You will need to set up concrete forms around the perimeter of the area you plan to pour the concrete. These forms hold the liquid concrete in place so it will dry to your preferred shape and size.

Forms are usually made of wood and must be installed properly to prevent concrete from leaking out and bowing the wood.

Rebar

To reinforce concrete and minimize cracking over time, you can install rebar. Rebar is usually made of stainless steel and comes in rods or mesh sheets.

Using A Concrete Calculator

To calculate how much concrete you’ll need, first measure the length, width, and depth of the project area. Then enter these values into an online calculator.

Concrete suppliers will usually give you a price per yard or cubic yard of concrete. You can calculate a cubic yard by multiplying the length by the width by the depth (all in feet) and dividing by 27.

To determine the depth you will need, consider these rules of thumb:

• 4 inches for patios and driveways; and
• 5 to 6 inches for concrete slabs that need to carry heavier loads, like dump trucks and heavy machinery.

Do consult with a concrete construction professional if you have a special project and you’re unsure of the required depth for your concrete.

Another rule of thumb when ordering concrete is to add 10% to the total amount to ensure you have enough to complete the project without any interruptions.

Tips and Advice to Keep Projects on Track

Plan for Extra Variables

Sometimes projects take a bit longer and cost a bit more than originally planned. To prepare for the unexpected, include some room in your budget and schedule so you aren’t caught off guard. Add a day or two to your schedule and keep some extra money set aside in case you need to buy more materials.

Use the Right Equipment

Having the proper equipment for the job will ensure your project is completed accurately and efficiently. If you’re not comfortable using certain machinery, get help from the concrete construction pros.

Ask for Help

Even DIY projects may require assistance from the pros, so don’t be afraid to ask for help along the way. Expert assistance will save you plenty of time and possibly plenty of money by avoiding mistakes and extra work.

Know Your Limits

While it would be nice to be skilled in all the trades, don’t attempt to do something you have no experience with, especially if it’s a dangerous job.

You can account for added labour costs in your budget. What’s more, you get to enjoy peace of mind knowing the job will be completed safely, accurately, and within schedule with a little help from the pros.

DIY Stone Measurements Tips and Tricks

A Guide to Measuring Quantities of Crushed Stone for Various Home Projects

Summer is here and home landscaping projects are in full swing. If you’re planning a DIY project with crushed stone this summer, local stone quarries can help you get the products you need to get the job done.

Crushed stone is an excellent material to use for a variety of home projects. From garden pathways to driveways, crushed stone offers a natural look all on its own, and is often used as a base layer for patios and driveways made of poured concrete or patio pavers.

Furthermore, stone also works well as a surface material for roadways, driveways, dog runs, dry creek beds, and other landscaping projects.

It provides a sturdy base for concrete slabs and pavers, and friction for vehicles when used on its own. Stone also allows for proper drainage, making this a versatile and durable material to many home project needs.

Once you’ve decided where to get your quarried stone, you’ve got to figure out how much you actually need for your project.

How Do I Calculate
How Much Stone I Need for My Project?

Crushed stone is generally measured in cubic yards. To calculate the cubic yards of your project area, measure the surface area of your project in feet.

For rectangular or square spaces, multiply the length (L) by the width (W) to get the area in square feet.

Circular locations are a bit more involved, but in general, measure the diameter and divide it by 4. Then multiply this number by 3.14 (or pi) to get the area of the circle in square feet.

(Note: For curved, winding, and other irregularly-shaped surface areas, contact quarried stone suppliers for help with measurements.)

Take the area in square feet and multiply by the depth (D) of the location in feet. Then divide this value by 27 to get the total cubic yardage needed.

The formula used for square and rectangular areas is:

(L x W x D) / 27 = cubic yards of crushed stone needed

The formula used for a circular area is:

(Diameter / 4 x 3.14) x D / 27 = cubic yards of crushed stone needed

As an Example

Say you want to order crushed stone as a base for a new concrete patio. The length of the patio is 20 feet, the width is 10 feet, and the depth is 6 inches (0.5 feet).

Use the formula to calculate the cubic yards for a rectangular area:

20’ x 10’ x 0.5’ / 27 = 3.7 cubic yards

Always round up the number so you have a bit extra to work with. So instead of ordering 3.7 cubic yards of stone, you will order 4 cubic yards of crushed stone.

To accurately measure the area for your project, first spray lawn-marking paint to create an outline of a path, patio, or other spaces designated for crushed stone.

Walkways, Patios, Driveways – Know the Difference

For projects such as walkways and patios, use a 3- to 4-inch depth of crushed stone beneath a 3- to 4-inch depth of surfacing material.

You will need to dig a depth of 6 to 8 inches in total. The total depth of crushed stone needed depends on whether you use it only for a base layer or for both a base layer and a surfacing material.

Since 4 inches is less than a foot, convert this value to a decimal. Divide 4 by 12 (the total number of inches in a foot) to get 0.33 feet.

For larger projects that will support more weight, such as driveways, use at least an 8-inch depth of crushed stone. For the formula, convert 8 inches to feet by dividing 8 by 12 to get 0.67 feet.

Crushed stones bases should provide a level surface, stability, and sufficient drainage

How Deep Should A Gravel Drive Be?

Gravel driveways should have three to four layers. These include:

• The optional sub-grade—compacted soil at the bottom of the excavated area for the driveway.
• The sub-base—the bottom layer of crushed stone that sits on top of the sub-grade and consists of larger crushed stone aggregate.
• The base—a layer of slightly smaller crushed stone that sits on top of the sub-base and may also include stone dust or fines.
• The surfacing material—the surface layer of gravel that is poured on top of the base layer and completes your crushed stone driveway.

Each layer of your driveway should be about 4 to 6 inches in depth. This means the total crushed stone portion of your driveway should be 12 to 18 inches deep.

How Much Does One Cubic Yard
of Crushed Stone Weigh?

In addition to measuring the amount of crushed stone you’ll need in cubic yards, you may also need to measure the amount you’ll need in tons.

The standard weight contractors use for crushed stone is 2700 pounds per cubic yard. So to calculate the amount in tons, multiply the number of cubic yards you need by 2700, then divide by 2000.

Always Order A Bit More

Remember to always round up the amount of crushed stone you’ll need so you don’t risk running out of material before completing your project.

Ordering a bit extra will account for compaction and ensure you have enough. A general rule of thumb is to add 10 percent of the amount you need to your order.

So, using the formula and dimensions from earlier, say your calculations show that you need 3.7 cubic yards.

Ten percent of 3.7 is 0.37 (3.7 x 0.10), so add this to your total, giving you 4.07. Depending on the quarry you source your gravel from, you may need to round up or down for your order.

If you want to order crushed stone by the ton:

(5 x 2700) / 2000 = 6.75 tons

You could then round up to a total weight of 7 tons.

If you’re don’t like math, try an online calculator. Simply input your measurements and the crushed stone calculator will do the rest of the work for you.

You can also contact your local gravel suppliers for help choosing the right amount and type of crushed stone from stone quarries to suit your project needs.

 

Building Better Concrete Products

How Additive Help Create Stronger, More Durable Concrete and Much More

Did you know that you can tailor your concrete mix to suit your specific project needs?

Concrete suppliers mix in additives to batches of concrete to improve specific qualities of the final product. This includes accelerants or retardants to speed up or slow down the concrete’s setting time. Additives help to improve workability, strength, and quality.

Researchers are interested in the role additives play in creating better, more versatile concrete products on a molecular level. This could lead to tailoring concrete products to changing climates and environmental conditions, creating incredibly versatile and eco-friendly concrete that offers a wealth of benefits for construction companies and the finished products they create.

We’re taking a closer look at some of the ways additives help create better concrete products – and what that might mean for concrete of the future.

What Researchers Are Looking For

Two of the biggest challenges of concrete production are durability and sustainability. Researchers are always looking for news way to produce concrete that improves on these qualities.

Using local materials is an obvious solution to help offset the greenhouse gas emissions present during the production process but poses challenges in and of itself. In some cases, durability comes at the cost of sourcing materials elsewhere.

Additives help make “going local” a viable option and can improve on pre-existing mixes in some cases.

Furthermore, the use of sustainable, durable materials with a longer design life means less reliance on concrete production to replace structures in the future.

Researchers have analyzed the individual atoms in concrete that contribute to strength and durability, using this information to develop a computer model that simulates the behaviour of individual atoms, forming molecular building blocks in hardening material.

This research aims to find ways to create concrete products that are strong enough to withstand the increasing pressures of environmental conditions, such as earthquakes and floods, which place stress on concrete buildings and infrastructure.

Researchers are specifically examining how additives (such as volcanic ash from various regions and refinery slag) mixed into cement improve the cohesive and frictional forces of groups of atoms. The effect of these local additives on concrete mixtures could make concrete mixes better suited to specific regions for a more sustainable product.

Common Admixtures

Most concrete mixes today contain chemical additives, also known as admixtures. These help speed up concrete construction projects by making concrete easier to pour and work with. As a result, this increases productivity and cuts costs.

Admixtures also increase the strength and durability of concrete, reduce the amount of water needed in the mix, and speed up or slow down the setting time.

Local suppliers frequently use specific admixtures in your concrete mix based on your concrete project needs.

Let’s take a closer look at five common existing admixtures used in concrete mixes today:

1. Retarding Admixtures

Retarding admixtures slow down the setting rate of concrete by delaying the chemical reaction that starts the setting process. This makes concrete more workable during placement in hot weather.

These admixtures are necessary in hot weather since the heat can increase the concrete’s setting time.

When heat makes concrete harden faster, the concrete’s workability decreases, making placing and finishing the concrete difficult.

2. Accelerating Admixtures

Accelerating admixtures speed up the rate of early strength development in concrete.

This reduces the time needed for proper curing and protection, meaning finishing operations can start earlier.

Accelerating admixtures are especially useful in cold weather since the cold reduces the rate of setting.

3. Air-Entrainment Admixtures

Air-entrainment admixtures increase the durability of concrete during the freeze-thaw cycle. It also increases concrete’s workability and reduces bleeding and segregation.

These mixtures place microscopic air bubbles into the concrete, which prevents cracking from stresses such as water expanding in freezing temperatures.

4. Water-Reducing Admixtures

Water-reducing admixtures reduce the amount of water content required for a concrete mixture by 5 to 10 percent.

Concrete with this admixture will have a lower water-cement ratio, needing less water to reach the desired slump.

This makes it possible to produce higher-strength concrete without increasing the amount of cement used in the concrete. Less reliance on cement is more affordable and sustainable. Lower cement content reduces CO2 emissions and energy use per volume of concrete.

Water-reducing admixtures improve concrete properties, make it easier to place concrete in difficult conditions, and are more stable across a wide range of temperatures.

5. Superplasticizers

Superplasticizers—also known as plasticizers and high-range water reducers (HRWR)—reduce water content by 12 to 30 percent.

Superplasticizers create high-slump flowing concrete out of concrete mixes with low-to-normal slump and water-cement ratios. This increases the workability of concrete, making it highly fluid and easy to place with little to no compaction.

Superplasticizers only increase concrete workability for 30 to 60 minutes, so concrete contractors will usually add superplasticizers to the mixture at the job site instead of at the concrete plant.

What This Could Mean for Concrete In The Future

Concrete additives improve workability and durability. And with the current research into the role additives play on a molecular level, concrete additives could eventually be tailored to changing climates and environmental conditions, such as withstanding natural disasters.

The use of concrete additives sourced locally, such as recycled fly ash, will reduce the carbon footprint of concrete production, especially if this means less reliance on cement for the production of concrete.

Better quality concrete tailored to withstand environment stressors will last longer, requiring less concrete production in the long run. This will result in fewer CO2 emissions and, with any luck, a greener future.

How Are Aggregates Used in Concrete?

A Look at the Role Aggregates, Sand and Gravel Play in Concrete Mixtures

Aggregates play a major role in concrete mixes.

These materials hold the concrete together, influencing the workability of wet concrete and the durability of the finished product.

Furthermore, the characteristics of included aggregates directly affect the performance of a concrete mix.

Everyone knows cement as a concrete ingredient, but it might surprise you to learn that aggregates such as sand and gravel comprise up to 80 percent of most concrete mixes.

Consulting with local gravel and sand suppliers in Ottawa can help you determine the optimal aggregate mixture for your next project,

What Aggregates? How Are They Used In Concrete?

In concrete, aggregates are the granular substances that hold a concrete mix together in its solid form.

Aggregates vary in size and shape, ranging from fine sand to coarse gravel and crushed stone.

When combined with cement and water, aggregates create a bond that holds concrete mixes together.

Optimal Concrete Mixing Tips

The best concrete mixes are low-cost, easy to work with, easy to pump, and don’t shrink once they dry. Easier said than done, in some cases.

The gradation, size, weight, and moisture content of aggregates directly affect the character and performance of your final concrete mix.

If cost-effectiveness is a top-of-mind concern, select the largest allowable aggregate size. Using larger, coarse aggregates typically reduces the total amount of cement (the most expensive ingredient in a given mix) you need to use.

Using less cement also means less water in the final mix, assuming the water-cement ration stays constant. In turn, this helps reduce the risk of shrinkage and cracking during the curing stage.

Aggregate Proportions in Concrete

Concrete mixes usually comprise:

As mentioned earlier, though, not all aggregates are created equal.

The aggregates you choose contribute to overall consistency, strength, workability, and durability.

Quality

High-quality aggregates are clean, hard, and strong with durable particles. Ideally, you want aggregates that are free of clay coatings, harmful chemicals, and other contaminants that affect the hydration of cement and reduce the paste-aggregate bond.

Also avoid using aggregates that:

Moisture

Since aggregates absorb water, it’s important to take this into consideration when mixing concrete. The moisture contribution or absorption by aggregates will affect the water-cement ratio and the overall strength of the concrete.

Ready-mix concrete uses aggregates that are in a saturated surface dry (SSD) condition. This means their absorption is satisfied, so the aggregates won’t add or take away moisture from the concrete mix.

Gradations

The proportions of coarse and fine aggregates you use in your concrete mix will depend on the aggregate characteristics, the placement method, and the desired finish.

Fine Aggregates

The fineness of aggregates is measured using the fineness modulus (FM). The FM for fine aggregates should be within the range of 2.3 to 3.1.

Aggregates that are too fine will have a high water demand, and will also result in a sticky concrete mix.

Coarse Aggregates

The largest allowable size of coarse aggregates used in a mix will depend on the size, shape, and reinforcement, and shouldn’t exceed:

When aggregates are too coarse, they create harsh concrete mixes with low workability. This makes the concrete more difficult to place, consolidate, and finish.

Tips for Mixing and Working With Concrete

The ratio of aggregates to sand to cement determines concrete’s compressive strength.

Compressive strength measures concrete’s resistance to downward force in pounds per square inch (psi). Concrete mixes typically range in compressive strength from 3000 psi to 4000 psi. The higher the compressive strength, the more weight the concrete can support.

The amount of water you use to mix the concrete also affects this strength.

The strength of concrete is inversely proportional to the water-cement ratio, which is to say, the more water you add to mix the concrete, the weaker the final product. Less water leads to a stronger concrete mix but also makes for a more difficult workability.

It normally takes 28 days for concrete to cure and reach its optimal compressive strength, but some mixes cure faster.

Not sure what the ideal compressive strength is for your project? Check out these guidelines:

Mixing Ratios

To create a concrete mix of around 3000 psi, you need a concrete mixture ratio of 1-3-3:

For high-strength concrete (around 4000 psi), use a mixing ratio of 1:2:2:

Make sure to measure out the dry materials accurately before mixing, and add a bit of water at a time to achieve the desired workability.

Working with aggregates might seem like a headache waiting to happen, but knowing a thing or two goes a long way towards helping your finished concrete project stand the test of time.

What is Concrete Compaction?

How to Ensure Optimal Concrete Ready Mix Strength Through Proper Compaction

You know how to mix and pour concrete. But have you learned how to compact it?

The concrete compaction ensures optimal density and strength, not to mention an excellent surface finish.

That said, a smooth surface does not always mean the concrete underneath is properly compacted.

We’ve put together a helpful guide to teach you how compaction works, and how you to ensure you properly compact a poured concrete ready mix.

What Is Concrete Compaction?

The compaction of concrete removes entrapped air from freshly poured concrete. It also packs the aggregate particles of the concrete mix together. The result is a stronger, denser concrete with low permeability.

How is Compaction Done?

Tamping concrete is a common compaction method on many job sites, but using vibration is by far the most efficient method for long-lasting concrete that looks great. Concrete construction projects often use external, surface, or internal vibrators for concrete compaction.

Internal Vibrators

Internal vibrators are the most common means of compacting concrete through vibration.

These vibrators must be placed vertically into poured concrete. The vibration action helps bring air bubbles to the surface of a poured slab. Once the air bubbles stop surfacing, place the machine in another area of the concrete slab.

You must move systematically throughout the slab until you achieve proper compaction.

External Vibrators

External vibrators are frequently electric or pneumatic devices mounted to the exterior of a work form. These cover a much larger area than other vibrators and are usually spaced 6 feet apart from each other.

External vibrators are ideal for walls and beams and should be run long enough for air bubbles to escape.

Surface Vibrators

Surface vibrators work from the top surface of the concrete, compacting the surface and what’s immediately below it. Contractors may use these with a screed to help level and finish the surface.

Depending on slab thickness, you may use a variety of surface vibrators during a given job.

The Compaction Process

The proper compaction of concrete is a two-stage process that requires slumping and removing trapped air.

Stage 1 – Slumping & Liquefaction

When concrete is first placed, aggregate particles arch against each other. This prevents slumping by internal friction.

But an immersion vibrator will:

This stage takes about 3 to 5 seconds to complete.

This stage provides a smooth level surface. But the compaction process is not complete until the trapped air has been removed.

Stage 2 – Expel Entrapped Air

Newly placed concrete of normal mixes (not mixes with very low or high workability) contains between 5% and 20% by volume of entrapped air.

An immersion vibrator will bring these trapped air bubbles to the surface of the concrete. This process takes about 7 to 15 seconds to complete since it takes a bit longer for entrapped air to rise to the surface.

Once air bubbles no longer appear on the surface of the concrete, the compaction process for that area of the concrete is complete.

What Can Happen to Concrete That Is Not Properly Compacted?

Both under- and over-vibration of concrete can lead to quality issues. However, under-vibration, or no compaction at all, poses far more problems for poured concrete.

Concrete loses compressive strength and becomes weak if it’s not properly compacted, and the risk of defects in the concrete is greater.

Common defects from poor-quality concrete include cracks, concrete honeycombing, and concrete spalling.

The low compressive strength is unable to withstand heavy weight, such as that from vehicles or structures resting on top of a foundation.

High permeability, meanwhile, allows moisture to seep in and saturate the concrete. This can lead to cracking, especially in winter when the moisture freezes and expands.

How to Avoid Under- and Over-Vibration

To avoid defects in the properties of concrete, you must use the appropriate type and amount of vibration.

The concrete mix needs to be properly proportioned. Mixes lacking fines (stiff mixes) are more difficult to compact and are more porous. Mixes with too high a fines content are prone to segregation and excessive bleeding, especially if they have a high slump.

It’s difficult to over-vibrate mixes that are properly proportioned, but you should take care to not under-vibrate these mixes, either.

Stiff mixes with lower workability need more energy for proper compaction, so use a high-energy vibrator or you should vibrate the concrete for a longer period of time. Either way, the vibrator should have enough power to liquefy the concrete.

Concrete mixes with higher workability need less energy for proper compaction.

The properties of the coarse aggregates in the mix, such as size and angularity, also affect your compaction efforts. Larger and more angular aggregates need more effort to compact than smaller aggregates with smooth or round edges.

When and Why You Should Compact Concrete

You should compact concrete immediately after pouring and placing the concrete in a form.

Freshly placed concrete typically contains 5% to 20% entrapped air (air voids). The higher the percentage of trapped air, the weaker the finished concrete slab will have.

Freshly-placed ready mix concrete that contains 10% entrapped air could have 50% less strength than properly compacted concrete.

The proper compaction of concrete is necessary to maintain the concrete’s structural integrity and gain optimal strength. The many benefits of concrete compaction include:

The proper compaction of concrete will lead to durable, long-lasting concrete.

Keep these tips in mind for your next concrete project, and order proportionately-mixed concrete from your ready mix supplier.

How To Measure Concrete For Any Project

Tips to Calculate Enough Concrete to Order from Concrete Suppliers

Now that warmer weather is here, it’s a good time to start planning concrete projects around the home. Maybe you want a new concrete slab for a shed or a backyard patio. Or, maybe you want to redo your garage floor and driveway.

Whatever the project, it’s important that you order enough concrete to get the job done in one pour. The last thing you want when placing concrete is to run out mid-way through.

Concrete slabs placed in one pour are much stronger and will last longer than concrete poured at separate times.

To avoid running out of concrete in the middle of your project, you’ll need to measure the right amount before ordering from your concrete supplier.

Even with a concrete calculator, you need to take a few things into account when measuring the right amount of concrete to pour. And in some cases, you might need to make some measurements on the fly.

To help you order the right amount of concrete for your project, we’ve compiled a few helpful measurement and calculation tips.

Tools You’ll Need

Calculating the Amount Of Concrete

Take Measurements

Using the tape measure, measure the area where you plan to place the concrete, writing down the following measurements:

Use a Concrete Calculator

Concrete calculators are available online from concrete suppliers. Simply input your measurements, whether in millimetres, centimetres, metres, inches, feet, or yards. The calculator will do the work for you to find the volume of concrete you’ll need for your project.

Calculating Cubic Metres

If you took metric measurements, then multiply the length by the width by the depth (L x W x D) to find the volume needed in cubic metres. For measurements in centimetres, multiple the measurements by 100 to find the amount in metres.

Here’s an example of how to calculate area in cubic metres:

15.2 m (L) x 4.6 m (W) x 0.1 m (D) = 6.992 cubic metres

Calculating Cubic Feet

To calculate cubic feet or cubic yards, you first need to convert your measurements in inches to Engineer’s Scale.

Engineer’s Scale takes one foot (12 inches) and converts it into tenths. This scale also eliminates fractions of an inch, converting fractions into decimals (i.e. ½ to 0.5, or ¾ to 0.75).

To illustrate this conversion, the following measurements will be used as an example:

L = 12 feet, 6 inches;

W = 15 feet;

H (D) = 3 and ¾ inches.

Since you only need to convert the inches to feet, any measurement in feet will remain the same.

Converting Length (L) of 12 feet, 6 inches to feet:

Converting Height (H) or Depth (D) of 3 and ¾ inches to feet:

To measure the cubic feet, multiply the three converted measurements together (L x W x H).

12.5 feet x 15 feet x 0.31 feet = 58.25 cubic feet

Calculating Cubic Yards

To calculate the measurement into cubic yards, take the total cubic feet and divide by 27 (which is the number of cubic feet in a cubic yard).

58.25 cubic feet / 27 = 2.15 cubic yards

Safe Rules of Thumb For Ordering Concrete

When ordering concrete from your local concrete supplier, keep these rules of thumb in mind to ensure you order enough concrete and the right mix for your project needs.

Add 10%

Once you’ve calculated the amount of concrete needed to fill an area, add 10 percent to that amount to account for spillage and possible variations in slab depth.

Multiply the number by 0.10, then add this value to your total amount.

For example: 2.15 cubic yards x 0.10 = 0.215

0.215 + 2.15 cubic yards = 2.365 cubic yards

Concrete Strength

Concrete mixes come in various strengths for various uses. For example, a concrete driveway will require more strength than a shed since it will be holding the weight load of vehicles. The strength of concrete is measured in pounds per square inch (psi).

So when you order concrete from your concrete supplier, make sure to tell them what the concrete is being used for. Depending on your project needs, they will recommend a specific strength of concrete mix. And if you live in Ottawa, or any other temperate location with a freeze/thaw cycle, your concrete supplier will also suggest a specific percentage (i.e. 5%) of air-entrained concrete to withstand the fluctuating temperatures without being damaged.

Keep these measurement, calculation, and ordering tips in mind so you can pour the right amount of quality concrete during your home projects this summer.

Why Stone Works for Your Home

A Remarkably Versatile and Sustainable Material Sourced from Local Stone Quarries

When you think of building a home, what materials come to mind? Most likely your mind goes to concrete, brick, and wood.

Have you ever thought about using natural stone for construction?

Stone is a durable, low-maintenance building material that lasts for years. It’s remarkably versatile and eminently sustainable when it comes to home construction, especially if you’re sourcing from local stone quarries. Best of all, the look is unbeatable.

Not sold on stone? Don’t worry, we’ve compiled a few reasons for you to give it a second chance.

Let’s take a closer look at why you should consider using stone as a building material:

Longevity and Sustainability

Due to its long-lasting qualities, stone is one of the most sustainable building materials. It won’t need replacement for years, nor will it end up in landfills as often as other materials. Other building, such as wood, brick, manufactured stone, and synthetic materials, wear down much faster than natural stone.

It’s tough, too. Natural stone doesn’t show the same wear and tear as other materials will and is less likely to be damaged by moisture. Keeping it clean is easy, too; chances are, stone materials won’t easily show dirt, scratches, and stains. A stone kitchen countertop won’t show the same damage as wood or synthetic materials. And stone is perfect for enduring the constant moisture in bathrooms.

Perfect for use both inside and outside the home, stone actually looks better with age. Hard to beat that!

And because of that longevity, stone’s recyclable. Stone from deconstructed buildings can be reused in several ways, including retaining walls in gardens or mosaic wall designs if the stone is broken down.

Processing – What Processing?

Unlike other building materials that need processing after sourcing, natural stone can be used as is. Once extracted, stone is a fully formed and finished product that doesn’t need to be baked or heated. Without processing, it won’t emit more CO2 into the air.

Synthetic materials, such as carpet and vinyl, release toxic chemicals in homes. Their volatile organic compounds (VOCs) release vapours or gas in a process called off-gassing. Off-gassing materials give your home a “new home smell,” but actually compromise your indoor air quality.

Stone is a natural and abundant earth material that can be found nearby. You can source stone products from local stone quarries to reduce the overall carbon footprint of a build.

Passive Heating and Cooling Benefits

Natural stone can passively heat and cool homes with strategic placement based on the sun’s position in the sky in the winter and summer.

For heating, stone captures the sun’s heat and release it into the home gradually during the day and night. This keeps homes evenly heated throughout the colder months, resulting in fewer cold drafts and less strain on heating systems.

Since the sun is higher in the summer, the sun doesn’t beam directly on a stone wall and the stone doesn’t capture the sun’s heat. Instead, it captures heat from the home’s interior, helping regulate indoor air temperatures in the warmer months.

This passive heating and cooling reduces energy consumption and costs and places less of a demand on heating, air conditioning, and energy grids.

Home Décor Options

Natural stone is attractive and versatile, offering numerous design and décor options in the home. Several of these actually help boost curb appeal, and can even add to property value.

Kitchens & Bathrooms

Since stone is impervious to moisture, this material is extremely useful in bathrooms and kitchens. Stone floors, showers, countertops, and sinks add durability and luxury to these designs.

Kitchen countertops take a lot of stress, from hot cookware and chopping to water and moisture from foods. This regular wear and tear will damage synthetic countertops over time.

But stone countertops, such as granite and marble, can handle the heat, scratches, and moisture in a kitchen. And since they are easy to clean and hard to scratch, you won’t have to worry about bacteria buildup, making them safer for food preparation.

The cool, flat surface is also ideal for rolling out pastries and pizza crusts. And the counter will never warp if you place a hot pot or pan on top.

Flooring & Walls

The durability and slip-resistance of stone make it a great flooring material, especially in high-traffic areas of the home. Scratches and dullness are rarely seen, and stone floors are easily cleaned with sweeping, mopping, and vacuuming.

If you ever want to add radiant heating to your floors, stone is the best material for this heating system since it absorbs and retains heat.

Like stone floors, stone walls are resilient and attractive. And as mentioned before, they can work in favour of your home comfort with passive heating and cooling.

Landscaping

Stone is a practical landscaping material since it is strong, weather-resistant, strong, and offers drainage. Common uses for stone in landscaping include walkways, patios, retaining walls, and planters.

When it comes to outdoor landscaping and patio materials, stone fits right in with the natural outdoors. Insects, such as termites, can’t eat away at stone. And stone will withstand the stresses of the weather and environment. It won’t warp or crack from extreme heat or cold, nor will it rot from too much water. It can take prolonged exposure to the elements without disintegrating over time.

For a versatile, attractive, and sustainable building material, opt for natural stone from your local stone quarries. Natural stone is worth the investment since it will boost your home value and last a lifetime.