One of the most dreaded things about winter is its damaging effects on concrete. This can be a costly and frustrating problem, but it doesn’t have to be! 

There are numerous easy ways to help avoid concrete cracks this winter. Follow these steps to prepare your driveway or other concrete slabs for the cold months ahead.

Seal your concrete surfaces 

In winter months when snowfall and low temperatures freeze the top of your concrete, frost damage can occur if they are not sealed. Sealing your concrete protects the surface and makes it easier to remove any ice as well. 

Remove debris

Regularly scraping away any leaves that fall onto your concrete as the seasons change is vital to protecting your driveway or other concrete fixtures. Leaves and other organic matter will prevent your concrete from getting the proper exposure to sunlight it needs in order to avoid freezing.

Repair any damaged concrete

If your concrete has become damaged or is already cracking, you need to take care of it as soon as possible. 

Cracked concrete exposed to freezing temperatures can cost thousands of dollars to replace and is likely to continue deteriorating over time if you do not repair it before temperatures continue to drop. 

Be sure to inspect all areas of your property that have concrete. It is possible that your gazebo, deck, or walkway might need replacement too.

Be careful with salt 

Using too much salt as a melting agent can actually damage your concrete, causing it to become brittle and more likely to crack. It should only be used in moderation. Fortunately, in Louisiana, this shouldn’t be too much of a concern for us. 

If you follow these steps, you can avoid the nightmare of having to replace cracked concrete this winter season. Don’t wait another day to start protecting your concrete. 

With the Louisiana weather being as unpredictable as it has been the past couple of years, there’s no telling what this winter will bring. Start taking steps to protect your driveway now and contact Port Aggregates for assistance. We look forward to helping you keep your concrete safe this winter!

The post Avoiding Concrete Cracks in the Winter: How to Prepare Your Concrete appeared first on Port Aggregates.

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Women in South Asia have long been doing intense physical labor in building sites and brick industries for relatively low pay. And, yet it is discouraging to be a part of a heavily male-dominated construction industry. Whenever I passed by a construction site, I felt powerless and afraid of the tools that men carried effortlessly, as if to prove that gender disparity in the labor market exists for a reason. In other words, the construction world felt unattainable in all its toughness.

Image Source: Women at work © The Record Nepal

As an aspiring architect, the dichotomy between architecture and construction seems nonsensical, particularly in the ever-evolving realm of sustainable architecture, where prototyping and experimenting are at the core of design processes. There is also an assumption that architects are above construction workers – a dynamic that sustains social and class imbalance. While there are many structures to criticize about, luckily, there are also associations like Critical Concrete who facilitate three-weeks of intense, hands-on workshops to understand the material, building techniques, and teamwork as part of the post-graduation course in sustainable architecture. The workshop positively shifted my perspective of the construction industry and further expanded my own personal boundaries.

“Let’s get our hands dirty!” architect Hanno Burtscher, instructed a team of ten women who came from different professional backgrounds, race, and geographical locations. Hanno introduced himself as an earthman, with an Austrian sense of humor, quick wit, and great teaching style, he grouped students in pairs to use all four senses except for sight to identify the local materials used for raw earth construction. This is how the welcome ceremony to the workshop began and it had already set a higher bar for the rest of the workshop. The joy of sharing stories moved the conversation from endless banter about cheese and food to serious topics like what sustainable construction means and how the uncertainty during the time of pandemic has affected our lives. In short, the day exuded a sense of togetherness. 

*Sketch by Charlotte Schneider, Alumni, Post Graduation 2020-2021

WEEK 1 | RAW EARTH CONSTRUCTION | HANNO BURTSCHER

The first week of the workshop was a battle – a battle to make proper earth mix to build a heated earthen bench and flooring for the kitchen at Critical Concrete. From the start, we learned that the key components of earth mix are clay, small gravel (0-5 mm), big gravel (5-15 mm), sand (0-4 mm), and water.

Most of us were already aware of the composition elements through our Raw Earth online course, but what made the difference in the practical workshop was the experimentation and improvisation in the mixing process since the excavation materials were available in limited amounts. The question constantly surfaced during the workshop – how do we make the most use of what is available around us? And this was a revelation in itself because theoretically, we learn the ratio – 40% of excavation, 20% of small gravel, 20% of big gravel, 20% of clay, and water – to achieve the desired mix. 

In practice, however, there had to be adjustments in the ratio based on the materials that were available to us. The way we integrated the composite materials together also made a big difference in the quality of the earth mix. So, at times we had to find creative ways of using what was available to us.

“While nearing the end of the earth mix for the floor, we ran out of the large size rocks. My typical mindset is to say, “Let’s just go buy more.” However, with the mindset of Critical Concrete to use what we already have, we were not going to buy more. To finish the mix, we scrounged throughout the construction yard looking for proper sized rocks and were able to get the right volume,” Mary shared her experience. And this was the general experience during the workshop – how to find sustainable solutions when we hit a roadblock.

In our earliest days of the workshop, we dropped a fist-sized earth mix balls from 1 meter height to see whether they stuck together or crumbled. We concluded that the ball should drop in larger pieces rather than completely shattering or sticking together. If it’s too sticky, either the clay or water content is too high which will result in a mixture that won’t be suitable to create a form. The same logic applies for the dry mixture as well. After a process of trial and error, we realized that there was no concrete recipe to achieve the perfect mix. But there were a number of factors that determined the quality of the mix. One of them is the clay content, which is normally 20 percent in total but depending on the situation, it could range from 5 – 30 percent. The purpose of the clay is to bind the materials but the more surface area we have in the mix, the more clay we require, from which we can derive that the smaller the surface area of excavation, the higher clay content would be required to bind it. Simple physics!

Many construction sites are not inviting spaces for women. Women’s work is often considered too frivolous to the degree that they are rendered valueless in the number-driven capitalist economic system. During the workshop, this dynamic was challenged. A team of mostly women and Hanno prepared the foundation for raw earth flooring and built the formwork for the bench. As I was lifting heavy stones and using power tools, I occupied a space that was not ‘normalized’ for women. I quickly realized that the problem wasn’t these too feminine, delicate hands but rather it was the devaluation of women’s work that put women in confinement of patriarchal ideas.

“We either put 100 percent into this or we don’t do it at all,” Hanno remarked while we were putting earth mix into the form work. The workshop was fueled by this exact mindset but was also filled with laughter and leisure in between our hard work. Overall, during the first week with Hanno, he guided us by observing the way we were interpreting the materials. We were able to experiment with the materials and make decisions based on our judgement.

Week 2 | Esposende Building Site | Hugo Dourado, Pietro

Degli Esposti, Martina Eandi

Esposende was roughly a forty-minute drive away from the city of Porto. And when the drive is long, conversations of past, present, and future start bouncing around.

“How do you say it?” Bara from Czech Republic asked.

“Vastu Shastra,” I repeated.

“And that means harmony of energy through design? That is how I would like to design the interior of my place one day,” remarked Charly from Germany. 

The conversation moved in such a way during the Esposende trip. The practical workshop as a part of the post graduation course merged people with similar ideologies, dreams, and passion of bringing social and political change through architecture and urban planning. The workshop also meant more than fulfilling a part of the course. Some of us had flown miles away leaving their usual life to come to Portugal to venture in a new journey.

*Sketch by Charlotte Schneider, Alumni, Post Graduation 2020-2021

The building site was under construction, so there were different tasks that the students could choose from such as fixing the board and batten cladding system, wood charring station, tiling the roof, or constructing a rocket stove.

The name rocket stove in itself made me curious. On top of that, I had also done some research on rocket stoves in one of the Participatory Design courses. I started my second week with Pietro, our Raw Earth course instructor and Martina, Mycelium course instructor, to complete the stove that could be used for both cooking and heating the entire house.

The making of the rocket stove involved lots of earth mix, it didn’t involve knowing rocket science at all. First, a stone wall had to be built to lay an exhaust pipe with an inclination of 30 degrees. The purpose of this was to carry the smoke from the rocket stove out of the house. For the stone wall, we prepared Argamassa (mortar) to attach stones of many sizes together and this alone took days to finish. As soon as the wall was completed, we started to make the exterior of the rocket stove with earth mix. The earth mix was ¼ part lime, 2 ½ part excavation, and ½ part straw. Since we were working with materials that were locally available, the excavation we were using included large stones. We wanted the mix to be a combination of lime, earth, and straw, so we sieved the stones out.

At times building with raw earth felt like cooking, in a sense that there is a process to achieve the result. You cannot skip a part to make the process faster, there is a procedure that you must follow otherwise the mix will not be suitable for construction. Therefore, while making the earth mix, it is important to completely let lime and excavation combine before putting any water. Once lime and excavation are completely mixed, giving off a grey-brown color, you slowly add water and straw to make a mixture. We used the cob technique to compress and compact fist sized balls, smashing it to attach them onto the pre-existing walls.

Slap slap slap!! We were hitting the earth mix on the side with a board to pack it down together. Another important thing that Pietro shared with us was that the cob technique allows us to build 30 cm per day. Since the earth mix is massive and wet, it needs time to dry and be compacted to build another layer on top of it. To keep the layers of earth mix interconnected, we created a vertebra-like structure at the end.

​​The rocket stove workshop made me realize how earth as a material is flexible. I could mold it in any shape I wanted and working on it with hands felt therapeutic. With the rocket stove, we were trying to achieve a dome shaped exterior to give it a character of its own. We molded the earth mix into long tiny sausages to create a curve on the upper part of the stove. It was interesting to see how earth could be shaped into any form with the right formwork which is also one of the big advantages of working with this natural material.

Life on Site

The Esposende building site was located between the ocean and mountains. In the early morning, you could see the tip of the mountains covered in fog and in the late afternoon during those early hot, summer days, you could see the blue ocean in the distance. With our cup of coffee that the Critical Concrete team prepared for us every morning, the day started with division of tasks and the students always got to pick first which task they wanted to be involved in.

After our coffee we all got into the groove and the site came to life again. Some of us were carrying heavy stones, using power tools, hanging on the roof putting tiles while others were listening carefully to what Hugo, our Vernacular Architecture course instructor, with immense knowledge and a sense of perfection, had to teach about board and batten cladding systems. It was fascinating to observe how everybody worked individually and in teams and clearly I wasn’t the only one who thought this. The neighbors in Esposende would walk by observing, commenting on our work, with their hands clasped behind their backs!

“It’s called umarell in Italian,” Linda shared jokingly.

Apparently, in Italian slang, umarell is when elderly people gather to observe construction sites and comment on how to do the work, often with holding their hands behind their back.

I became a umarell when it came to food. The Critical Concrete team prepared big batches of healthy, colorful vegan food during lunch time and we would all observe in awe. The variety of food made from simple ingredients that Critical Concrete provided us inspired me to be creative with food that we eat on a day-to-day basis. How many times do we actually think about eating in a sustainable manner? How do we creatively use leftover food in our diet? These questions among many others helped me unlearn and learn new ways of looking at sustainability.

Week 3 | Furniture Workshop | Samuel Kalika

I noticed how different building materials can be. Whereas with raw earth, exactness is not so important, with wood each millimeter is important. Building beautiful furniture requires many steps, patience, and exactness,” Viviana shared. After working with flexible material like earth, wood seemed like unlocking a whole different dimension. Samuel, our Participatory Design course instructor, understood this well and he made our work easier by giving us instructions on every powerful tool we were using.

Precision was the key. While cutting wood, if it’s 1 cm off, what could we do? We could not undo a cut once it was made neither could we adjust it, so a big part of the furniture workshop was to find a solution on the spot. We used many different tools to achieve the desired finish and construction: a universal machine to obtain desired thickness, sizes, flatness, and straight surfaces; the meter saw; the sander. Gradually the counters for the kitchen in Esposende house began to take shape. “As soon as I started approaching the work, I understood the importance of being precise in all the small details. Once we developed a good flow in the process, the work became easier and faster,” commented participant Linda Tonin.

*Sketch by Charlotte Schneider, Alumni, Post Graduation 2020-2021

While trying to achieve precision, mistakes are bound to occur but this is part of the learning process and that made the experience lighter and took away the fear of judgment. 

“To assemble the pieces, in particular for the bigger elements, we set up a strategy, naming the pieces of wood and measuring the different thicknesses needed for the joining beams. Since different people worked on the cutting process, sometimes the joints’ holes had different sizes. We took these mistakes as an occasion to add different colors of wood to fill the spaces: the mistakes, at the end, added aesthetic value to the furniture pieces,” Linda reflected.

REFLECTION

During the whole workshop, each one of us were sharing our experience of working in different environments. We were trying to understand what our preferences are, what materials, tools we like to use, and which instructors’ teaching style catered to our learning approach.

“Beyond the excitement, time passing and the verge to finish, it was necessary to maintain a safe working space, making sure you and everyone around is comfortable and don’t cause any danger. Having this in mind, I learned how to remain calm and careful with all the tasks, machines and my colleagues. This atmosphere brought a lot of awareness and future-thinking into my habits,” Agnieszka described her experience.

“Starting with the fact that the workshop took me out of all my comfort zones, I can say that the first learning was that the “unknown” can be very good. And the learnings went beyond practical. Being in contact with such an international and so human team certainly awakened in me my best version, my confidence in a more correct and viable future and made me reflect and work on my limiting standards. It was definitely a great achievement to be in a healthy work environment,” shared Júlia.

I resonate with both Agnieszka and Júlia. My experience with working in a group was liberating. It taught me how everybody in a team works differently — how each individual works, thinks, coordinates and cooperates while working on a project. On top of that, our group was very diverse, so learning from each one of them and getting to interact with everybody in-person felt special during this uncertain pandemic time. We were able to transfer our expertise and learn from each other’s skills. At the same time, we were a group of women doing construction work, realizing our own potential and that was empowerment in itself.

On a personal note, the workshop also altered my relationship with the construction industry and my perception of emancipated women. Historically, women have existed within the confinement of domestic space therefore women who occupy space outside of the predictable situations are labeled ‘modern’. And if the working conditions are healthy and their work is comparable to the status of a male, they are given recognition and visibility. But are all women able to get the same visibility and prestige as the emancipated, educated women? Women from lower class and caste in South Asia have been working in extreme conditions in construction sites and brick factories out of economic necessity. They have to go through daily work toxicity in a largely male-dominated workplace. While reflecting back on the practical workshop, I realize the utter importance of an equal workplace environment in the labor industry and greater recognition of those women who have paved the way.

The post An SSA student’s perspective on working in construction and practical workshops appeared first on Critical Concrete.

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A lot of you will be familiar with reinforced concrete as a building material, but may not be aware of the finer details. Commercial concrete is often a good solution for building work, we will be discovering a bit more about why this is the case, and the best ways to go about using the material for your building projects.

Everything You Need to Know About Reinforced Concrete

Commercial Concrete

This is concrete used as part of a building project, often used to create or enhance business facilities, industrial buildings, warehouses and retail stores. In an average building, you will find commercial concrete in plenty of spaces, such as the walls, floors and even some architectural details. A large majority of commercial buildings would have been put together with heavy use of commercial concrete. Like domestic concrete it has many benefits when used on a building site, durability being one of the most obvious.

Domestic Concrete

Domestic, or residential concrete usually has less demand placed on it in terms of structural performance and durability, but in itself, it is still considered a durable building material. Domestic concrete floors and pavements usually require a lower strength mix design and lighter reinforcement than commercial concrete.

Concrete Pumps

The purpose of a concrete pump is to have a tool that can convey liquid concrete. This works by having one piston drawing liquid concrete into a cylinder from a hopper while the other piston simultaneously pushes concrete out into discharge pipes. There will be a valve which can determine the cylinder that is open to the concrete hopper and the one which is open to the discharge pipes, which gets switched over each time the pistons reach an endpoint, with the process continuing with the first cylinder now discharging and the second drawing fresh concrete from the hopper.

Concrete Services

If you need to deal with reinforced concrete there are a couple of things that are crucial to consider. You need to make sure that if you are laying the material yourself you know what you are doing with it. You must also make sure that the concrete is of a high-quality standard. You must have the facilities to mix it correctly as well as an appropriate skill/strength level to physically handle it/the required machinery.

Alternatively, you may need to use the services of a professional concrete company, like Base Concrete, to prepare and lay the concrete and get your building project completed. Commercial concrete can be a great asset to all sorts of projects and can be purchased with some very good deals, just make sure you are only ever involved in using the services of professional and trusted companies. It is almost a guarantee that your area will have quite a lot of concrete services operating in your area where you can purchase your desired amounts of commercial concrete or have a service bring around the material and lay it on your behalf.

So, for all your concrete needs, contact Base Concrete today on 01442 389105. For more details, visit our contact page.

The post What is Reinforced Concrete? first appeared on Base Concrete.

You may just see concrete as a flooring option that is a pretty standard arrangement, one that places tend to opt for if they can’t think of a better choice. But some noteworthy reasons make concrete a great choice for flooring, it can elevate a stepping space to the next level… Let us take a look at 6 great benefits of concrete flooring and how it can transform the look of your property.

Strength 

If you know anything about the strengths of concrete, you will know that it’s a very durable mixture indeed. We’re talking about a material that can withstand very high volumes of weight, with strong pressure presenting no issues whatsoever. Heavy equipment and vehicles would not be enough to make a dent on a concrete floor. So a concrete floor can easily take all the foot traffic and moving of furniture that the average household is likely to take part in regularly without any issues!

Long-lasting

This durability means that the concrete will hold up and last for years to come. Especially if the concrete flooring is well looked after and sealed, you can expect it to last for a very long period before it becomes anywhere near being worn down. And even when the texture and colour begin to change with age, a long way down the line, that adds a bit of ‘character’ to the style of the flooring and is not a practical issue unless it actually becomes damaged in any respects.

Plenty of design options

Concrete does seem to be stereotyped as a boring flooring type, but that is quite unfair. Designers have come up with a wide range of options, with absolutely loads of different colour and textual effects to choose from. And don’t forget you can stain or paint the surface of concrete for your desired effects and also opt for other specialities such as polished concretes.

Reasonable 

If you’re cost-conscious, whether you’re looking to purchase domestic concrete or require flooring for office space, it remains one of the more economical options available. The clever aspect is that you can choose a faux floor pattern that resembles the style of a much more expensive flooring type for a fraction of the cost.

Easy to Maintain

Another big benefit of concrete is that it’s very easy to maintain. As mentioned, it will keep even better with a seal of some kind, a protective sealant that should be reapplied every 3-9 months on average. Regular sweeping and mopping will help keep the concrete looking fresh and new, but other than that, not much maintenance is required. Polishing your concrete is also a great way to keep it looking its best.

Good for Indoor and Outdoor

A final benefit of concrete flooring is it’s a reliable choice for both indoors and outdoors, so you can have it set up in your home or garden area.

You should enjoy selecting a great looking concrete flooring style, but there is also an alternative option. Consider hiring a mini concrete mixer which for a very small daily fee can produce your required amounts of concrete from the comfort of your garden! This can work out to be a very affordable way of getting the job done! So, for all your concrete needs, contact Base Concrete today on 01442 389105. For more details, visit our contact page.

The post Why Concrete is a Great Choice for Floors first appeared on Base Concrete.

Lots of people fear using concrete. If it goes wrong, it can be difficult to fix, but for smaller domestic jobs it’s actually a lot easier than many people think. With this guide, we’ll go over the different ways to mix concrete so you can decide what’s best for you when attempting your DIY project.

Concrete Proportions

Concrete has 3 main ingredients. Cement, aggregate, and sand. These ingredients are mixed with water, which when dried out, binds into a solid, very hard material. Depending on what you’re using the concrete for, these can be mixed in different proportions to give you different finishes and strengths.

It’s very important to get these proportions correct. With too much sand, your concrete won’t be hard enough to withstand the test of time. However, too much aggregate and you’ll be rushing to find a way to cover it up and pretend that it isn’t there.

Mixing Methods

In a domestic setting, there are several different approaches you can take to mix your concrete. If you’re happy giving the different proportions a go, you can either do this by hand or by using a mixer. For small scale jobs, mixing by hand can be ideal as it’s easy to keep track of the consistency and see how it’s going. This can often be a good thing to do as a practice if this is your first time. For larger jobs, a concrete mixer can save you hours of time and strength mixing larger amounts of concrete together.

When it comes to domestic concrete, it’s often overlooked that there are some other options also available to you, especially for slightly larger jobs such as concrete bases for sheds, summerhouses and other garden accessories. The main differences between domestic and commercial worksites are space. Often with a commercial worksite, the work will be planned to make these processes as efficient as possible, allowing the concrete mixers to reverse right up to where they’re going. However, this doesn’t mean you can’t utilise similar methods.

Types of Concrete Mixers

There are two main different types of concrete mixer. There are ordinary concrete mixers and also volumetric concrete mixers and both of these have different uses. You’ll likely have seen ordinary concrete mixers or mini mixers driving around quite frequently. These have the advantage of being able to transport one of many different mixes of concrete. Extra ingredients can be added to the concrete at the factory in order to provide different properties such as waterproofing or extra fibres for additional strength. However, this isn’t often needed when it comes to domestic concrete.

The other type of concrete mixer is a volumetric concrete mixer. These are ideal for domestic concrete as you don’t need to worry about having too little or too much. ‘Mix as you go’ concrete mixers contain the raw ingredients needed and as you pour out the concrete will mix it straight away. They also have the added advantage over traditional concrete mixers of being able to supply multiple different mixes of concrete to the same job without having to pay the additional cost of bringing in a second load.

Concrete mixers and volumetric concrete mixers are also a great choice for people taking on DIY projects that don’t want to take the risk of getting the mix wrong. All you’ve got to worry about is where it goes with the extra guarantee of knowing that it will stand the test of time. Thank you for reading this blog post. Should you have any enquiries, feel free to call us on 07812 182778 or visit our contact page for more information.

The post How to Mix Concrete by Hand or in a Mixer first appeared on Base Concrete.

When it comes to getting a durable concrete slab, a critical part of it involves keeping the concrete resistant to abrasion. Without that resistance, construction professionals will often encounter ruts, dips, potholes, or worse in the surface of their concrete. All of which can lead to safety hazards and operational inefficiencies.

Professionals usually try to counter this with conventional surface-applied concrete hardening solutions. But these aren’t reliably effective and come with a number of setbacks.

To look into why that is, we’ve decided to explore the bad, the good, and the better parts about concrete abrasion resistance. Helping us in this discovery are two of our Smart Concrete experts: Jeff Bowman, one of our technical directors, and John Andersen, our territory manager for Western Canada. To start, let’s dive into some of the negative aspects surrounding concrete abrasion resistance.

Thank you for joining us on the first part of this interview series. Let’s start by discussing what abrasion actually is and why it is an issue for concrete in the first place.

Jeff: Abrasion describes the steady loss of material from the concrete through some sort of mechanical action. It’s generally more of a surface phenomenon. So forces that are acting on the abrasion of concrete are usually going to be some sort of object that’s either rolling or sliding over the concrete. And this may also be combined with foreign particles trapped between those two phases that are also gouging and sliding through the concrete.

John: When we talk about the significance of that wear and tear on concrete, we typically think about just the cost of taking the building out of service and replacing the concrete. But there’s also a cost regarding safety. And it’s not just about the people tripping and falling and encountering all other hazards because of it. There’s also an issue of breathing in the concrete dust, the cost associated with keeping the facility and machinery clean, the cost to the equipment, and the reduced productivity due to the worn out concrete.

How exactly do construction professionals usually try to resolve this issue?

Jeff: Dry shake hardeners are quite a common product for this. I’m sure many people reading this now probably use or specify them.

But for anybody who’s not familiar with them, a dry shake hardener is some sort of blend of cement and possibly some other additives and an abrasion-resistant aggregate particle, such as aluminum oxide (also called emery). And these products get broadcast in a dry form overtop fresh concrete and then worked into the surface during the final finish.

Now, certainly, these products can work and can give you a good abrasion-resistant finish if they’re installed well. The challenge that the industry has is they’re very difficult to install.

Dry shake hardeners are applied in two portions, and there’s some work that needs to be done in-between. And one of the significant challenges of this application is that it all takes place in a very time-critical period. All the steps are time-critical, and it can be very easy to miss that perfect window of opportunity.

There are just so many variables that could be happening with the concrete and with the weather. And if workers start to have trouble with it, sometimes they just can’t get a full specified amount of the dry shake applied to the concrete.

John: That’s exactly the challenge that the contractor Graham Construction faced when they were building a new pea protein plant in Manitoba. This is a massive facility with large slab pours, and they were trying to get that shake-on hardener down in that little window of opportunity. And they lost the first slab.

They eventually changed to Hard-Cem to get away from the challenge of that little window of opportunity for properly applying the shake-on.

re there other challenges that come with using dry shake hardeners?

Jeff: Another challenge that we see is that this work normally comes up fairly late in the day when workers have been at it for many hours and they’re just getting fatigued. This is a lot to put on them at the end of the day.

Another challenge that we see is that the dry shakes are very sensitive to bleed water. If there’s too much bleed water coming out when you apply the dry shake and you work that water back in, the surface will become weaker and is likely to delaminate. If you have a low-bleeding concrete, perhaps something with a lot of fly ash, there’s just not enough water there to really work it in properly. The concrete sets up too quickly.

There can also be challenges with wind. And of course, it’s very important not to use dry shakes with air-entrained concrete because the power troweling needed to really work them in properly leaves a high risk of delaminating the concrete surface. So there are many challenges to dry shake products that people might face.

There are also some products that professionals apply post-construction, right? What about those?

John: Yes, I think if you’re in Western Canada, where I live, many of these products use silicate as the base for their formulas.

Jeff: Right. When we’re describing liquid hardeners (which are sometimes called liquid densifiers), these are all some sort of silicate-based product. They work by penetrating into the concrete and reacting with the calcium hydroxide there, which is a by-product of cement hydration. That reaction turns into what is called calcium silicate hydrate gel, which is the normal hydration product of cement. It’s what gives the cement paste its strength and what gives concrete its properties. So this reaction pathway is really quite similar to the reactions you get from fly ash or slag or other supplementary cementitious materials.

That introduces some challenges in and of itself. Some suppliers of these products recommend limiting the amount of fly ash or slag you’re using in your concrete. That’s not always possible or desirable for many other reasons. Or they may recommend delaying the application for at least 28 days to allow the concrete to come up to its specified strength first so that the silicate is not competing with the other cementing materials.

Does their application work effectively?

Jeff: While they are often used or specified specifically to increase the abrasion resistance of the concrete as placed, that’s not really what they’re intended to do.

They function by slightly increasing the amount of cement paste on the surface. But cement paste is the weakest and most vulnerable phase to abrasion. Having a little bit more doesn’t significantly move the dial on the abrasion resistance of that concrete.

Now, liquid hardeners do serve an important purpose. If a contractor does have a slab that has had some challenges when they’re placing it, the surface might be poorly hydrated or weak or might have dried out too early. These products can help strengthen that surface as a remediation measure.

But they’re not really an appropriate material to specify as an abrasion-resistant material for concrete that’s been otherwise properly placed and finished.

re there other solutions that have been used to increase concrete abrasion resistance?

Jeff: Another common solution is high-strength concrete.

And why not just use stronger concrete? You get better abrasion resistance. And normally, this approach would be just using a mix that has more cement. You could use more fly ash or slag or maybe silica fume to really get that strength up and keep that water-cement ratio down real low. The concrete gets stronger, and the abrasion resistance is better. And this generally does work.

But there are some limitations.

Now, the research shows that when you double the compressive strength of concrete, you can roughly double the concrete’s abrasion resistance. And there is research and literature on this.

But there can also be some consequences. Any time you are using a stronger mix, especially with anything that has more cement paste, you’re getting more hydration. That generates more heat in your concrete. More paste means more shrinkage. More shrinkage normally means more cracking. And if you’re pouring a slab, you also now get more curling, so your floors just don’t stay as flat. And curling can result in a lot of damage and wear at the joints.

All of these things are actually really bad. They target some of the core properties that a facility owner expects of their floor. An owner wants more than just good abrasion resistance. They want their floor to perform in many other ways.

And as an added bonus, using high-paste strong mixes comes with a cost premium. Because you are using so much more cement in the concrete, the carbon footprint of that concrete can go up quite significantly.

So most popular concrete abrasion-increasing efforts don’t seem to work as well as expected. Is there a better way to get that abrasion resistance?

John: Adding Hard-Cem into concrete at the batch plant! Hard-Cem lives in that concrete paste, and that’s how it works. It increases the resistance to abrasion and erosion that way. It’s easy to apply. There are no negative effects on your plastic or your hardened concrete. It’s fully compatible and used often with air-entrained concrete, so no longer do you have to specify products like this just for indoor use. You can now use it outdoors. And it can be used in horizontal and vertical slabs, behind formwork, in precast, and in shotcrete. There’s a huge opportunity for this product to be used often in mining applications as well.

And Jeff very clearly articulated the difficulty in applying the shake-on hardeners. So no longer do the jobsites have to take all this into consideration. Basically, they can just order Hard-Cem when they order their concrete. And there’s no harmful dust exposure.

Hard-Cem’s been used for 18 years now for over 7 million m2 (80 million ft2) in all kinds of applications. And many of the top-producing concrete companies have branded their own durability concrete using the Hard-Cem admixture.

Once concrete finishers get to use this, they start to ask for it by name because it just makes their job that much easier.

It sounds like Hard-Cem could be a much more effective solution. But how well does it perform? We’ll look into that in more detail in Part 2 of this interview series.

The post Concrete Abrasion Resistance: The Bad, the Good, and the Better (Interview Part 1) appeared first on Kryton.

Lately, there’s been an increase in interest over the well-being of coral reefs. These marine habitats represent an estimated $2.7 trillion in ecosystem service value and support around 25% of all marine life after all. But we have already lost 50% of the world’s reefs at this point. And there appears to have been no specific global funding to help develop the protection and restoration of these reefs in the past.

Recognizing this, a coalition of partners from the 75th session of the United Nations General Assembly created the Global Fund for Coral Reefs. With this fund, they hope to raise and invest $500 million (USD) to support programs that will increase the resilience of coral reefs.

That means you may soon see more construction requests for artificial reefs. These sorts of reefs are manufactured constructs designed to promote the growth of coral reefs and provide marine life with shelter. It’s a great way to secure a profitable tender and give back to the environment all at the same time.

But if you do decide to take on an artificial reef project, what can you expect?

You May See a Wide Variety of Structural Requests

Over the years, the innovation for building artificial reefs has only increased. People from all over the world have their own ideas on how to build reefs effectively. So when you do encounter such a project, you might find some unique structural requests. Here are just some of the more well-known ones you might end up with.

They May Be Complex Like a Habitat Skirt

If you win a bid for an artificial reef construction project from a governmental authority, your work may be fairly large and complex.

For instance, back in 2008, the Vancouver Convention Centre used governmental funds to include a habitat skirt worth $8.3 million. The first of its kind at the time, this project used 362 precast concrete slats. They were fit into 76 frames and arranged to look like a large five-tiered staircase. That extended the center’s shoreline by 477 m (1,564.96 ft) and added 6,122 m2 (65,896.66 ft2) of marine habitat surface area.

That is no easy feat for a project that had never been done before! As one of the University of British Columbia’s blogs notes, this amount of space is equivalent to “the length of five Canadian football fields and the floor space of the entire White House.”

It’s also not the only government project thinking big. Further south, down in the United States of America (USA), in San Diego, the port there has started to install a sea wall. Designed to protect the edges of Harbor Island, the wall is expected to help restore the island’s marine ecosystem.

It makes use of a structure that consists of the Coastalock system, which interlocks hollow concrete units to create habitats for oysters, sea stars, algae, and a variety of other marine wildlife.

The port hopes to use 72 of the 3.5-tonne modules of this system to replace the island’s current riprap.

With those two projects in mind, you can see that certain artificial reef projects will involve a decent amount of construction material, some intricate design input, and a keen contractor eye to keep everything working smoothly.

Or They May Be a Smaller Affair Using Reef Balls or Cubes

Not every artificial reef project is so extensive of course. There are plenty of people around the world who go to the Reef Ball Foundation and ARC Marine to install concrete structures in waters. These structures may be circular or more cube-like in shape, and they can range in size. Some may be as small as 0.3 m (1 ft) or so or as big as 1.5 m (5 ft) or more. In either case, the structures come with holes and various surface textures to offer marine wildlife places to rest and hide from predators that still look and feel like natural reefs.

They aren’t always interlocked and don’t need any additional design work. So it’s easier for people to order these structures from the organizations making them or from contractors for these organizations and have either group deploy the structures into the water.

It also makes it a less complex project on your end if you win a contracting tender for an organization that already handles this sort of work.

It May Even Involve Just Deploying Structures or Materials in a Specific Part of a Marine Area

Sometimes building artificial reefs is all about the structures or materials and nothing else.

In some cases, that might mean placing defunct ships, oil rigs, or some other old, large structure into open waters.

In other cases, it might mean doing the same but with defunct subway cars! Running with that last idea, the State of Delaware in the USA has been pushing old New York City Redbird subway train cars into the open waters off the coast of Slaughter Beach since 1996. However, to make sure these cars are marine-friendly, they strip them of any glass, seats, signs, wheels, and petroleum products before dumping them. That way, water can flow in and out of the old vehicles, allowing larvae from sea invertebrates to safely drift in and gain shelter, which in turn, lets them flourish and feed other marine animals.

An even simpler version of this project that you might encounter could be a request to place concrete pipes or steel beams on the ocean floor. For instance, further south from Delaware, in Pinellas County, Florida, such projects have helped to create around 42 reefs.

These Requests Can’t Just Be Fulfilled with Any Material, However

While some projects will already have a specific material in mind like those using the reef balls or reef cubes, there will be others with more leeway. And when that happens, you’ll need to carefully consider what material you use.

Think of it as building a home of sorts. You wouldn’t just use or reuse any old material for a person’s home. It could end up being structurally unsound or even toxic for the person who chooses to live there.

The same can be said for building artificial reefs. If you choose to build reefs by reusing waste like old tires or polyvinyl chloride, you’ll soon discover that neither material is the right kind for marine wildlife to call home. They’re usually too small, for one. So organisms needed to create reefs can’t grow on them. And they’re also very unstable. The waves can carry them to any part of the ocean floor easily, which is not appealing to marine wildlife as reefs are meant to be naturally anchored to the seabed. What’s worse though is that they can both release toxic chemicals, transforming their potential to be homes into a danger zone for any aquatic creature nearby.

So, what can you use instead?

Concrete Is Often the Preferred Material for Building Artificial Reefs

You might have guessed it already considering how often previous projects have used it already. But concrete really is one of the more preferred materials for building artificial reefs. And there are a number of reasons why that’s the case.

According to the New Heaven Reef Conservation Program, some of those reasons have everything to do with the composition and versatility of concrete.

Much like reefs, the composition of concrete makes use of the chemical compound calcium carbonate. Reefs get it naturally through coralline red algae, which form a calcareous skeleton that supports coral reefs by cementing them together. Meanwhile, concrete often gets the compound through common building materials like limestone. But regardless of how they get the compound, that makes concrete at least seem more natural to marine wildlife.

That’s not all that gives its composition such an appeal. Concrete is also innately strong and heavy enough to remain anchored at the bottom of any waters it’s placed in and lasts for a long time, giving marine wildlife a secure shelter for protection or habitation.

But what about concrete versatility?

Well, because concrete can be constructed into almost any shape and size, it gives you an opportunity to give an artificial reef any number of nooks and crannies that fishes and other aquatic wildlife like to hide in.

However, There Are a Few Other Materials You Could Work With

With that said, concrete isn’t the only material that people have gone for when building artificial reefs. They have also gone with the following materials using unique methods:

Electrified steelUsing biorock technology, ecologists in Indonesia have been able to form artificial reefs with electrically charged steel structures. Using a low-voltage current to charge the steel, the ecologists create an interaction between the electricity and the minerals in the seawater. That reaction causes limestone to grow on the charged steel. That growth eventually solidifies, forming reefs much quicker than they naturally would otherwise. This method has also shown to heal injured coral up to 20 times faster than other methods.

Steel spiders Even without electricity, steel remains a good material for building artificial reefs. For instance, people off the coast of an Indonesian island have been attaching parts of coral reefs to rust-protected reinforcing steel structures known as steel spiders. Over time, this process increased the amount of coral on the steel spiders by over 60%. At least 42 different coral species were growing on the steel spiders because of this. And in the rubble surrounding the steel spiders, people found at least 58 species.

Glass bottles in concrete While this method still uses concrete, the main focus is the glass bottles embedded in the concrete. As the concrete keeps the glass bottles anchored securely, the bottles themselves act as a way to transplant broken or nursery corals to attract marine life to the area and eventually create a reef and feeding hub for fish.

If You Do Go with Concrete, Consider Increasing Its Durability

As you know by now, concrete has a lot going for it as a material for artificial reefs. So if you do choose to use it, you know you’re in good hands.

But like with anything, you want to make sure you’re using your chosen material as effectively as possible. Part of that means making sure the concrete for your reef lasts for as long as possible. After all, artificial reefs are meant to be a lasting solution to the loss of so many natural reefs worldwide. And they won’t last if they don’t remain a permanent fixture in the water.

There are plenty of solutions out there that can help you strengthen the life span of your artificial reef, however. So which should you go with?

Here are some good choices that you might want to consider first:

Con-Fume One major artificial reef organization in the USA, the Reef Ball Foundation, requires silica fume in the specs for their artificial reefs. So if you want to follow their design as a blueprint for your own artificial reef, you may want to apply our Con-Fume solution. It is a silica fume product made from pozzolanic material to produce high-performance concrete. It comes in ready-mix bags and meets ASTM and CSA standards for silica fume.

Hard-Cem If you happen to be placing your artificial reef project in waters with swift currents, you may want to add Hard-Cem to your concrete mix. With fast-flowing water, there’s a higher chance for debris to bump up against your reef structure, gradually eroding away its surface and even potentially causing cracks. That surface will likely weaken after some time, leaving it vulnerable to losing aggregate and cement binders to the fast-moving water. But with Hard-Cem, this possibility becomes less likely. As an integral hardener, Hard-Cem increases the abrasion and erosion resistance of concrete and doubles concrete wear life even under harsh conditions. So it is capable of giving your artificial reef the durability it needs to withstand the abrasive and erosive forces in the water.

Krystol Internal Membrane

(KIM Another issue that can threaten your artificial reef’s longevity is a sulfate attack. Sometimes caused by industrial water pollution or seawater, a sulfate attack can chemically change the reef’s cement, weakening its bond with the surrounding aggregate. That can then cause extensive cracking and wear, ruining the structural integrity of your reef. Luckily, KIM can safeguard your reef from such a situation. Using Krystol technology, it enables your concrete to react chemically to water, forming needle-shaped crystals that fill up its capillaries and micro-cracks. That ensures the sulfate in the water cannot get through your concrete and damage its structure. KIM was also one of the top-performing products at preventing the corrosion of steel reinforcement during a 10-year study in a marine environment by the University of Hawaii. Moreover, KIM is also NSF-certified as safe for potable water and has the Singapore Green Label, proving that it is non-toxic.

You’ll Soon Have an Artificial Reef Perfect for Clients and Marine Life

Knowing what to expect and what tools to consider now, you’ll be ready to create a marine-friendly artificial reef of your own in the future. Just keep in mind the potential scope, materials, and obstacles you might encounter, and you’ll have an artificial reef up in no time.

The post Building Artificial Reefs: What to Expect appeared first on Kryton.

While it doesn’t look like silica dust is going away anytime soon, you may want to consider using an alternative material for your worksite when possible. After all, regulations in the United States of America (USA) are starting to get tighter. And it’s possible those restrictions will become the norm for other countries too.

In fact, just last year, the USA’s Occupational Safety and Health Administration (OSHA) launched a national emphasis program on the material. It’s an initiative that’s meant to restrict silica dust exposure due to the risk it can pose for workers in a number of industries. As a result, you can now expect more inspections on your management of the material. And if your management doesn’t follow the updated regulations, you could face monetary penalties from $5,000 up to $70,000.

Not long after these restrictions were implemented, the inspector general for the U.S. Department of Labor argued for stricter standards for silica dust management in mines. Those included making use of more frequent silica sampling protocols and issuing citations and fines for excess silica dust exposures.

Similar plans for stricter regulations were approved in 2019 in Australia. The hope was to limit the silica dust exposure that stonemasons in the country experience. While regulations were tightened to a degree, they weren’t tightened as much as planned as there was concern over giving businesses enough time to meet the new compliance requirements.

But why is there such resistance? What makes silica dust so appealing and concerning at the same time? Is there no way around this infamous construction material?

To get a better understanding of the situation, we’ll take a deep dive on the subject. Join us as we delve into why silica dust is popular, what makes it dangerous, and how you can minimize its usage.

Hard to Avoid, Silica Dust Comes from a Number of Helpful Construction Materials

Whether we like it or not, silica dust comes from a very common mineral. Known just as silica, this mineral is found throughout the earth’s crust. It can come in two different forms: crystalline and noncrystalline silica. That first form is the one we often call silica dust. And it comes in a form of its own known as quartz. It too is also easily found throughout the world as it’s a basic component in sand, gravel, clay, granite, and various rocks.

As you can probably already tell, that means silica dust can be pretty hard to avoid. It’s in a lot of basic construction materials:

ConcreteCementMortarTilesBricksRock- and stone-based asphaltBlasting abrasives

All of which are often the building blocks to a wide variety of construction projects. They help construction workers create buildings, warehouses, and many other structures.

In some cases, silica dust can even be found in products that are meant to help protect structures. That includes surface-applied concrete hardening products like dry shake hardeners.

It’s what makes it so difficult to avoid silica dust. It’s part of our essential building materials, helping to make it possible to construct projects in the first place.

But Its Help Can Come at a Serious Cost

So long as people don’t create dust with those materials, they’re fine. The crystalline silica just remains within the material, harmless to people nearby. In return, people can safely reside within durable concrete buildings, stand on nice cool tiles in their bathroom, and so on.

However, that’s not often the case during the construction of those structures.

It May Be Stable When Left Alone, but Once Agitated, It Becomes a Problem

Construction activities of all kinds can often kick up dust. These include, but are not limited to, the following:

ChippingSawingDrillingDemolitionAbrasive blastingTunnelingExcavating

Once those activities do start up and move some dust around, there’s a problem. That’s when it’s possible for crystalline silica to become dangerous and interact in ways it shouldn’t with our health.

That Makes It a Health Risk for Anyone Nearby

Essentially, as soon as silica dust is in the air, there’s a risk for people nearby to inhale it. Why a risk? Well, silica dust is a known carcinogen, meaning it can cause cancer in people. More specifically, silica dust is known to spur on the development of lung cancer. And that isn’t the only disease it can lead to. It can also cause people to develop kidney disease and chronic obstructive pulmonary disease.

After inhaling silica dust, people may even develop silicosis, which is particularly dangerous as there is no test for it. You can’t even easily define the signs of silicosis. Its symptoms match many other diseases after all. And you can’t recover from it either.

However, silicosis only tends to occur after you’ve been exposed to silica dust for 10–20 years. That may seem like a more manageable risk level to you. But keep in mind that if your exposure is intense enough, you could develop silicosis after 5–10 years or even after just a few months of exposure. And that’s only for this one particular disease!

In fact, it doesn’t take much silica dust at all to be a threat, whether you’re exposed to it over the years or within a day. That’s why OSHA limits a person’s permissible exposure level to silica dust to 50 μg/m3 over an eight-hour day.

Many Try to Mitigate the Damage of Silica Dust

Despite its risk, silica dust is still necessary for certain areas in construction. That’s why construction sectors and work safety organizations around the world take silica dust safety seriously. As a result, they typically apply the following safety measures and more to manage the application of the material in a responsible way that’s designed to keep construction workers and the overall worksite as safe as possible.

Part of That Includes the Use of Engineering Controls

These measures are designed to eliminate hazards like silica dust before workers come into contact with them. It’s what makes them more favorable than other measures like administrative controls and personal protective equipment (PPE). However, that’s also what can make them a bit more costly at the start. In the end, though, these controls are always good to have in the long run. While initially costly, over time, they’ll reduce operating costs for construction teams and keep them safe and healthy at the same time.

So, how does this work for silica dust?

There are a number of engineering controls that can be used against silica dust. These include the following:

Dust suppression — To prevent as much dust as possible from stirring at all, workers might choose to use water sprays. These might be sprays that can be attached to a tool like a pneumatic, hydraulic, or gas-powered saw. Or they might be sprays that form a curtain of water to protect a specific area from airborne dust particles. In either case, the idea behind it is that once dust particles come into contact with water droplets, they become heavier and are less likely to float in the air and pose a threat to workers.

Ventilation — When workers are agitating silica dust, they can use local exhaust ventilation to suck the dust away before it reaches their breathing area. For instance, if they are using hand-held cut-off saws to cut concrete, they can connect an exhaust hood (also known as a shroud) to the tool first. The hood is connected to an industrial vacuum cleaner with a flexible hose, which allows it to produce enough suction to capture the silica dust.

Industrial vacuum cleaning — Much like with portable ventilation, workers can suck dust away from areas through high-efficiency particulate air (HEPA) filtering vacuums. There are a variety of HEPA vacuums to choose from, including stationary, intermittent-filtering, and continuous-filtering models. So the efficiency of dust suppression with this method will depend. Though, workers should use one that has oversized filters. That allows the vacuum’s filtration system to collect a lot of dust and debris for a longer period than a vacuum with smaller filters.

dministrative Controls Also Come into Play

While not as favorable compared to engineering controls, administrative controls can be combined with them for extra protection. Under these particular controls, a construction team will determine the right work procedures that allow workers to do their job well and safely.

According to the Canadian Centre for Occupational Health and Safety, that can include implementing the following practices:

Worksite education — Without proper knowledge of silica dust, workers could have an increased risk to getting hurt while working near the material. To prevent that, it’s important all workers know what silica dust is, why it’s a threat, and how they can reduce that threat to a manageable level.

An exposure control plan — On top of worksite education, a construction team should have an exposure control plan. That ensures they will have a handy reference at their disposal that outlines the proper directions and expectations for preventing silica dust exposure.

Proper washing facilities on-site — To keep silica dust from spreading too far from the worksite, workers need to make sure they aren’t heading home in a cloud of the material. That might sound a little tricky, but all this requires is proper washing facilities at the worksite. These should provide clean water, soap, and individual towels. That way, each worker has the opportunity to effectively remove any dust around them.

nd for Extra Good Measure, Workers Have PPE

Similar to administrative controls, PPE is more effective when combined with engineering and administrative controls.

But this all depends on the equipment used! Some may find it easier to whip out a disposable dust mask and wear it. As the National Precast Concrete Association notes, it’s likely to be less hot to wear and easier to talk through than respirators approved by official safety authorities like the National Institute for Occupational Safety and Health (NIOSH). And with the word dust in that name, it sounds like it might protect workers from silica dust, right?

Well, unfortunately, that’s just not the case. Disposable dust masks are not NIOSH-approved. And they aren’t meant to really protect people from toxic substances. They’re actually better used as a way to stay comfortable while mowing grass or sweeping or dusting an area.

That’s why you want to go with an officially recognized and approved respirator. It’s designed to protect the wearer from all sorts of airborne contaminants, such as hazardous dusts, fumes, vapors, and gases.

On top of that, workers should also wear overalls and gloves to protect the rest of their body from coming into contact with silica dust. It also makes it easier for them to leave the dust at the worksite as they can simply strip off that uniform, leave it for cleaning on-site, and go home in their non-dusty attire.

But There Are Also Substitutes for Silica Dust to Minimize or Eliminate Its Use

You don’t always need to deal with silica dust or with as much of it as you might think. In fact, there are some great silica dust-free alternatives that you can use to keep your worksite just that much safer.

For a Silica Dust-Free, Non-Toxic Concrete Hardener, Look to Hard-Cem

It may be more conventional to harden your concrete with products like dry shake hardeners. But those often come with silica dust.

Luckily, you can eliminate this concern entirely when you use Hard-Cem. It’s free of silica dust. And as the only integral hardening admixture on the market, Hard-Cem has the unique ability to enter a concrete mix directly. Because of that, you don’t need to hire extra labor to apply it or have to worry about it not covering your concrete completely. You just add its dissoluble bag into the concrete mix during batching and let it permeate throughout the concrete. That gives the concrete full-depth hardening and increases its resistance to abrasion and erosion.

In return, you get concrete with double the usual wear life and a much more durable surface. That allows you to minimize the number of repairs or replacements you otherwise might need, which also reduces how much carbon your project emits.

There Are Also Many Other Substitutes for Different Applications

Of course, silica dust doesn’t just help with concrete hardening at times. It also helps with many other construction activities. So what can you substitute silica dust with for those?

While that may not be possible for every activity, you can substitute silica dust in the following activities:

Abrasive blasting — OSHA lists a number of silica dust substitutes for abrasive blasting materials. These include aluminum oxide, baking soda, coal slag, copper slag, and corn cob granules.

 

Precision grinding — The Workers Health & Safety Centre in Ontario, Canada, notes that grinding (also known as abrasive cutting) in construction can be done without silica dust. Instead of using sandstone grinding wheels, workers can use aluminum oxide wheels.

Silica Dust Doesn’t Have to Be a Problem at Your Worksite

It may feel like it’s everywhere (and in some cases, it certainly can be!). But you don’t have to put up with silica dust all the time. There are ways to not only mitigate its potential for damage but to also remove it entirely. Whether you choose to harden your concrete through Hard-Cem or use other alternatives, you can minimize the silica dust at your worksite, keeping workers safer and your worksite just as, if not more, productive.

The post Silica Dust: The Dangers and How You Can Mitigate Them appeared first on Kryton.

Elevated concrete slabs (also known as suspended concrete slabs) are most commonly found in commercial offices, parking garages, and other multistory heavy-use buildings. 

These pours require a bit more skill than your everyday residential concrete driveway and will need to be carried out by a professional contractor

Multiple factors are involved in pouring elevated concrete slabs, including the weight of the floor and the effect any additional loads will have on it. 

This is how it’s done.

1. The supporting walls are built according to the structural plans

The first step in pouring an elevated concrete slab involves building the supporting walls according to the structural plans. These walls can either be created out of reinforced concrete or concrete blockwork.

2. A crane is used to lower the metal into place

After the supporting walls have been constructed, a metal slab pan is lowered into place using a tower crane. This pan will be used as the framework for pouring and forming the elevated concrete slab. You can also use a system of connected preformed concrete panels instead.

3. Reinforced steel mesh is laid into the pan

Before the concrete is poured, reinforced steel mesh is laid into the pan and is lifted slightly off the floor using chairs (small metal supports) that are evenly spaced apart. This step is what gives the floor the strength necessary to support itself. 

In larger buildings, precast concrete floors that’ve been previously reinforced with tensile steel bars might be required for maximum strength. 

4. The concrete is poured and cured

Finally, after everything has been laid out and arranged according to plan, the concrete is mixed and poured in agreement with the structural engineers’ recommendations. 

The slab must then be left to cure for at least 48 hours before anyone can walk on it. The time it will take before anyone can park or drive on it will vary depending on several factors.

At Port Aggregates, our skilled contractors have over 40 years’ worth of experience built into our tried and trusted techniques. Whether you’re looking for a residential driveway, commercial suspended slabs, or precast concrete, we’ve got you covered. Contact us today to request a quote

The post How are Elevated Concrete Slabs Poured? appeared first on Port Aggregates.

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https://cedarparkconcrete.org/?p=218

If you’ve ever walked along a shoreline or under a bridge, chances are that you’ve seen what’s called rip rap

This rocky material is a form of crushed limestone that comes in a range of sizes. It can be anywhere from 4 inches to over 2 feet in width, depending on how fast the surrounding water moves and the steepness of the slope that it will be placed upon.

What Does Rip Rap Do?

The main purpose of rip rap is to prevent erosion on a pond bank, hill, or slope. Without this protection, roadways wash out, bridges become compromised, and property gets lost.

However, erosion prevention is not its only benefit. 

Contractors prefer rip rap because of its extreme durability and natural appearance. The reliability and affordability of this material make it the ideal choice for protecting bridges, pilings, shorelines, and streambeds from damage caused by water and ice.

Rip rap also buffers the impact of waves crashing against the shore and the force of water against the bank. In these cases, a larger grade (like our #1x4G) is installed over a textile for ultimate protection.

Where Can Rip Rap be Used?

Rip rap is most useful to structures or shorelines that are continuously exposed to rushing water. For example: near a bridge that’s located alongside an embankment, adjacent to waterway supports, and along a lake shoreline or the outer bank of a river bend.

It can also be used to build low-lying dividing walls or planting areas. In really steep slopes or high drainage areas, wire mesh or chain link is needed at the base of the decline to hold the rip rap in place.

At Port Aggregates, we offer three types of rip rap:

10lb rip rap (6-10”)30lb rip rap55lb rip rap

Regardless of whether you’re looking to prevent bridge erosion or simply trying to build a garden, we’ve got you covered. Our high-quality crushed limestone is available in a variety of shapes and sizes to meet your unique needs. Contact Port Aggregates today to request a quote

The post Rip Rap: The Original Rock Wall appeared first on Port Aggregates.

Did you miss our previous article…
https://cedarparkconcrete.org/?p=215