Hoses to Handle Abrasive Media: Concrete

After decades of experience using hoses and pumps in applications with abrasive media, Mike Bruce has gained a thorough knowledge on how best to handle concrete in a variety of different projects. Hose + Coupling World was happy to speak with Bruce about how he came to be in the concrete industries, what types of hoses are best suited to processes that involve concrete, and how to care for hoses and couplings properly.

By Brittani Schroeder and Angelica Pajkovic

Mike Bruce began his career working in construction, framing houses. “Construction was not a lucrative career back in the early 1980s. A friend of mine knew about a company called Pumpcrete so I thought I would try to broaden my skillset and started working there,” he said. When Bruce began at Pumpcrete, the company was considered a small operation. With only four pumps and a relatively small staff, he was able to obtain a welding mechanics job within the company, giving him his official start in the industry. During this period, Bruce gained experience with the hose fabrication process. “During the 1980s hoses came in rolls that we had to cut into ten foot sections using a band saw. Unlike today, where hoses are typically crimped by machines or have swage ends, we use to bind them by hand and pump in the steel end,” he explained. “The hoses often needed to be tied down, it was quite a process.”

After a few years working at Pumpcrete, Bruce moved on to a welding shop in Kingston, ON, before being asked to work on a concrete pump project in Nova Scotia. “I was hoping to get three weeks of thorough training before I went out east, but I think I only got about 20 minutes before I was on my way. It was quite the ride! I had to teach myself a lot,” he laughed.

In Halifax, Bruce worked on a barge creating concrete slabs, that were 100 feet long by 50 feet wide. “We would pour them on to a barge, and once the barge was out in the water, we would tip them into the water. Ten of the slabs would be fastened together and then sunk. That was how they built piers out in the harbor.” For this project, 25-foot-long hoses were run back and forth between the concrete walls, and used to lay the concrete.

“A 25-foot hose is pretty hard to handle and operate when you have never come across one before,” said Bruce. “The other guys on the barge were probably very frustrated with me because I did not know how to handle the hose properly. As we worked 12-hour shifts, I quickly became more versed with the process. When I returned to Toronto I was one of the best boom operators around.”

After gaining more experience in various roles in the concrete industry, Bruce went to work on pipelines for seven years. He returned to Toronto, ON when he took a position at Amherst, but soon decided to start his own company; Mike’s Concrete Pumping. “I bought a little inline pump, one of the smallest pumps found in the industry, and started my business. The pump is so small that I was able to put clamps underneath my pickup truck and tow the pump around. With the pipes and hoses in the bed of the truck I was able to easily move from one location to the next. I found that not many people like to carry around piping, so when I started my business, I did not have a lot of competition,” he explained. “Now I work with my son and his friends, but when they are back in school, it is just me hitting the road with the truck, and the pump.”

A Typical Day

Every morning Bruce arrives at his office at 6 a.m. to start his day. From there, it can take anywhere from a few minutes to an hour to drive to the day’s worksite.

“Regardless of the job requirements I always arrive at the site at least half an hour before the onsite crew, to set up all of the pipes and hoses,” explained Bruce. “The first thing we do once the concrete arrives is mix up a slurry to pour through the lines because everything is dry. Then we run about 100 feet of line. We use the steel piping to connect to the pump, and the hoses are connected at the end of the pipe. Depending on the volume of concrete to be poured, the hoses are typically 2.5-inch.” Once he finishes laying the cement the next step is to blow sponge balls through the line to clean everything up. From there, he can clean the pump and pack up to leave.

In one day, Bruce will schedule multiple jobs to ensure that his clients are getting the most efficient and effective service possible. “We will go from laying a basement floor in a 200-year-old house to pouring cement curved walls needed in a dairy barn. As each project requires different combinations of steel line and rubber hose, no job is ever the same,” stated Bruce.

Steel Hoses vs. Fiber Hoses

Bruce works with two principal types of hoses: steel and fiber. “Working with concrete is a heavy job,” he explained. “By itself concrete can weigh up to 5,000 lbs. per meter. When you take the weight of a 3-inch steel reinforced hoses, which weighs approximately 60 lbs. apiece, and then fill it up with concrete, each line you are working with can weigh 120 lbs. Working with the 2.5-inch fiber line therefore makes things a whole lot lighter. A couple of guys can move a 2.5-inch hose quite easily.”

Fiber hoses tend to be made of rubber and nylon cork. A nylon cork runs inside the rubber tubing and is designed with high pressure and abrasion resistance. Although the abrasive nature of the media will wear down the nylon cork, it is excellent for distributing concrete in challenging locations. Once the cork is worn down, or there are weak spots, the hose is compromised and the possibility of pressure induced ruptures or tears in the rubber increases.

It is no question that the steel reinforced hoses are stronger than the fiber hoses, but they do come with risks that differ from fiber hoses. “One of the big concerns with running an inline pump, in general, is that they are prone to plug ups,” explained Bruce. “Plug ups can occur in the elbows of the hose, or the reducers. Due to the extreme pressure from the pump, the plugged hose can explode and put anybody in close proximity at risk. Although this issue can arise in fiber hoses as well as steel hoses, the additional pressure required to burst a steel reinforced hoses can make it more dangerous than a fiber hose.”

Mitigating Risk

One way to mitigate the potential of exploding hoses is to always monitor the pump. “When we are at a job site, I always have either myself or my son watching the pump. If a hose does plug up, you can actually hear the pump building up pressure, while also being able to see the pressure gauge rising,” said Bruce. “If you are at the other end of the hose, away from the pump, you cannot hear when something is going wrong. The pump will keep pumping whether the hose is plugged or not. It wants to pump out that concrete, and if the hose is plugged, there is nowhere to pump it. By having someone watching the pump and the pressure gauge, you can quickly turn off that pump before a dangerous situation arises.”

The principal cause of hose failure in concrete applications is the repeated kinking of the hose to stop the flow of media. While a hose will degrade over years of use and weathering, the bending of the tube is typically what causes a decreased lifespan. This happens to both steel reinforced and fiber hoses. “If you have concrete flowing through the hose, and the line is running downhill, operators will often kink the hose to keep the concrete from spilling out of the hose. If this is done repeatedly, a weak spot forms in the hose. When there is a weak spot, explosions and ruptures can occur. This is why I always say, ‘Do not kink the hose’ because the possible risk is not worth it.”

Due to these risks, Bruce stresses the importance of wearing the proper personal protective equipment (PPE). “Sometimes people will wear the right gloves and the right body protection, but they are lax on the eye protection. If the goggles/glasses get dirty halfway through their work, they take them off because it becomes too hard to see. This is when they are most at risk and I have seen too many accidents happen. There are a lot of dangerous things we encounter on the job, and you need to protect yourself,” he relayed.

Hose Couplings

Another thing to keep an eye on are the hose couplings, Bruce emphasizes. “Hose couplings can vary from different manufacturers, and you need to make sure you are getting the best quality couplings, rather than the less expensive ones. You need to invest in a coupling that is right for your process, because it will help you out in the long run. I have seen cheaper couplings burst apart before, and that can be a real hazard.” The best maintenance for a coupling is to make sure it is cleaned frequently and oiled on a regular schedule. “This will keep everything in working order,” he said.

Hose Maintenance

The best advice for maintenance procedures is to always keep everything clean. “No matter what time it is, no matter how rushed we may feel, we always make sure to clean our lines properly at the end of each job,” Bruce stated. “One of the most efficient cleaning methods is to blow sponge balls through the lines. Sponge balls are special balls that can be blown through the lines with air that fully clean the pipes and hoses. The sponge flattens inside the pipe, just like a pancake, and the push the concrete slowly ahead and it comes out at the end of the line.”

Bruce warns, however, that not all sponge balls are made the same. “You can have two balls that look the same but they do not necessarily work the same. The air could go through the ball or around it, which can create air locks in the pipe; when this happens the ball does not know which way to go, so they do not clean thoroughly. To make sure they are clean, I run the balls through the line twice.” This second run of the balls prevents blockages in the line before startup. As Bruce explains, nine times out of ten, a plug will happen on startup, so you need to be watching the pressure gauge at all times.”

Bruce also pays special attention to sanding the inside of his hose lines and steel ends. “A problem with pumping concrete is that, after years of using the same pipes and hoses, 3-inch diameter hoses become 3 and 3/8 diameter. This can cause issue when you go to put a new hose in the lineup, The new 3 inch hose could have difficulty connecting to the coupling which can cause issues when attempting to pump harsher mixes. So sanding them down tends to help.”

In general, hoses tend to last a long time, as long as they are taken care of. “The eventually do get old and they need to be replaced just due to age, but unless something specific happens to them from the concrete, for example, they will last you a while,” Bruce explained. “In the 16 years I have had my business, I have only purchased approximately 10 hoses.”

The Joys of the Job

Being able to choose his own projects and work with a team he loves is one of the things Bruce enjoys the most about his work. “I get to work with my 19-year-old son and his friend, and I get to teach them about the experiences I have had. We get to see something new every day, and that keeps it interesting.”

Working with the concrete itself is the most challenging aspect of Bruce’s job. “Concrete companies are always changing their aggregates, because they go to where they can get the materials cheapest. This means that sometimes we end up with sharp stones, instead of round stone, which are ideal,” said Bruce. “In the past, everyone wanted round stones for pumping. Now we get all kinds of shards such as crushed granite, which is terrible to pump, and crushed limestone, which is a little better. The ideal mixture would be different sized aggregates, ranging from 1/8 inch to ¾ inch. If the aggregates are all the same size, they stick together like a puzzle inside the hose and become very difficult to pump.” Bruce has worked with many companies to procure the concrete he uses, and has built relationships over the years. “If one day I am having trouble with a new stone mixture, I can call up the provider and ask them how they can help and adjust the mix for me. It is a good relationship to have.”

“I really enjoy having the opportunity to help people accomplish their projects,” stated Bruce. “There is something very satisfying about making people’s lives easier and it is something I look forward to doing for years to come.”