Not too long ago, we talked about the versatility of Hard-Cem. But we never got a chance to discuss the benefits of it being in shotcrete. To rectify that, we’re here today to talk all about Hard-Cem shotcrete and why you should use it to get the durable concrete you need.
To Start, Let’s First Discuss Why Shotcrete in General Is Worth It
While shotcrete is a century-old form of technology, over the past couple of decades, many in the construction industry have started to renew their interest in it. After all, now more than ever, time is a precious commodity. The more time a project takes in construction, the more money it will need to keep going. And with shotcrete, construction workers can save plenty of time and avoid that increase in costs.
Well, shotcrete can help workers forego most of the time-consuming formwork typically needed for concrete pouring. Instead, they can use a hose, pump, and compressed air to spray concrete in place at high velocity. In turn, they often enjoy construction timeline savings between 33% and 50%.
It Eases Rehabilitating Infrastructure
On top of generally just saving workers time and money, shotcrete is a particularly effective method for infrastructure rehabilitation projects. For instance, it helps reduce the number of workers and equipment needed, which in turn decreases the congestion of a worksite. This is particularly important for roadwork as it allows a small, but efficient team to rehabilitate the areas needed on highways and elsewhere without fully obstructing the area.
And It Allows Countries Like Canada to Adapt to Shorter Construction Schedules
For countries like Canada that see more and more of their citizens head toward large cities, shotcrete is more than efficient. It’s a necessity. After all, the more people need housing in such high-demand locations, the shorter the time period is for construction. So workers need to adapt to these desired projects with tighter construction schedules, which shotcrete allows them to do with ease. In fact, quite a few downtown high-rise foundation walls in Vancouver, Calgary, and Edmonton have now been made solely with shotcrete technology.
So, Where Does Hard-Cem Shotcrete Fit In?
It’s clear that shotcrete itself has some benefits to offer construction. But what happens when you add our integral concrete hardener Hard-Cem into the mix?
What’s It All About?
Well, Hard-Cem is designed to enhance any mix it goes into. So shotcrete mixes would get the same benefits as any other kind. In this case, that means Hard-Cem can give your shotcrete mix a significant boost in surface hardness when it cures and a high resistance to both erosive and abrasive wear.
And as our previous article pointed out, Hard-Cem is quite versatile. So no matter what surface you’re using shotcrete for (horizontal, vertical, or inclined) or what its mix is (air-entrained or not), Hard-Cem is designed to work well with it.
Of course, to really determine its performance as a shotcrete mix, our manufacturer Cementec Industries Inc. decided to put Hard-Cem through a shotcrete test program.
Under this program, the Hard-Cem shotcrete was compared with a shotcrete mix that didn’t include the integral concrete hardener. Both mixes were batched and supplied by an independent concrete producer, and then, they were pumped, sprayed, and finished by an independent shotcrete nozzleman who was certified by the American Concrete Institute (ACI).
How Did the Two Tested Shotcrete Mixes Compare?
During this test program, the two shotcrete mixes had the following compared under the standard ACI 506R — Guide to Shotcrete:
- Vertical hang
- Air-entrainment compatibility
- Compressive strength development
And abrasion resistance was compared with ASTM C627 — Standard Test Method for Evaluating Ceramic Floor Tile Installation Systems Using the Robinson-Type Floor Tester. This test method was modified for concrete abrasion resistance assessment.
The end results were excellent. The Hard-Cem shotcrete mix was easy to work with and had no negative effects on placement and finishing. Strength was comparable and slightly higher for the Hard-Cem shotcrete compared to the control shotcrete. But where it truly shone was in abrasion resistance.
What about Their Abrasion Resistance?
Under the modified ASTM C627 abrasion resistance procedure, the two shotcrete mixes were used to create test panels, which were subjected to mechanical abrasion from three hard cast-iron wheels. These wheels revolved over the shotcrete surface under a heavy load. And for the duration of the test, the number of machine revolutions was recorded and the depth of the wear into the shotcrete surface was measured.
At the end, the Hard-Cem shotcrete withstood 2.5 times more abrasion than the other mix.
Of Course, Hard-Cem Excelled in More Places Than Just Testing
Hard-Cem shotcrete wasn’t just great at passing tests. It was also a project-proven product, helping a number of construction companies with their work.
Metro Skate Park Won a Number of Awards for Its Concrete Design
One particularly good example is that of Metro Skate Park. According to a report done on the work, the mix offered a compressive strength that exceeded their specifications. Because of this, construction workers used Hard-Cem shotcrete to form the bowl-shaped areas and full pipe of the park. Even the finishers were highly pleased with the concrete and how easily it allowed them to produce an excellent surface finish.
While this shotcrete mix wasn’t used everywhere, it was still used to great effect. And Hard-Cem still remained a major part of the non-shotcrete mix. Both factors played a big role in how well the park was received for years to come. In fact, over the years, Metro Skate Park has earned several awards for its concrete design.
Hard-Cem itself even earned a special mention from the City of Burnaby for helping create this project.
Iona Island Wastewater Treatment Plant Received the Durability It Needed
Still, Metro Skate Park wasn’t the only project to thrive under the application of Hard-Cem shotcrete. There have been a number of other projects, including one for the Iona Island Wastewater Treatment Plant.
While it had received a number of expansions since its creation in 1963, its concrete tanks used to filter and treat wastewater were now what needed an upgrade the most. Over the years, they were used to remove wood, stones, plastics, and other large debris. And all of the work that goes into that removal had slowly eroded the tanks. But luckily, the construction team repairing these structures chose to use Hard-Cem shotcrete. They sprayed it all over the bottoms and walls of the tanks, giving these structures the durable properties necessary to withstand abrasive and erosive forces during water treatment.
*Background photos courtesy of space2place design Inc.
It’s All Proof That Hard-Cem Shotcrete Has a Lot to Offer Projects
In short, Hard-Cem shotcrete is not just like any old shotcrete. It can give you concrete with slightly higher compressive strength and significantly better abrasion resistance. And it’s been proven to do so through many projects. So why not get the same experience for yourself? You can get started on your own Hard-Cem shotcrete journey by visiting our main Hard-Cem page.