Four stories about the core of the new EMA building
Fastening concrete reinforcement, placing steel anchors, casting concrete, smoothing out the outside: it's just a hop, skip and jump to the highest point of the core of the new EMA building. In the run-up we talked to a crane operator, construction site manager, foreman and safety expert about their work.
The safety expert
Everyone on the shop floor sees him walking around and talking to people: Martijn van Donk, safety expert. "I watch if people work in a safe way, we talk about it with each other and I give advice.” Martijn explains what safe working means. "It means that you consciously deal with risks. Suppose you have to grind something. Then you first have to think about what you grind, what you need for this and what additional personal protection equipment you need. Safety glasses or a face shield. Another example is using extraction when you need to drill. If that doesn't work, you have to use a P3 face mask.”
"So I pay attention to things like that," says Martijn. "I already do so with parties during preparation. They have to describe in advance how they will perform the work. And then I visit the people on the shop floor to see whether they perform the work as agreed. A little training and coaching of safety awareness on the shop floor.”
Safety comes first
The new EMA building should be ready in November next year. "It’s unique that we already know the deadline," says Martijn. "And then it requires a pretty tight hand and tight planning. Safety comes first, despite the pressure and planning. I see that speed of construction and safety go hand in hand.”
Risks when working at heights
Working at heights involves risks. Think of falling grit, pieces of concrete, bolts and nuts. "That is why we have set up a building safety zone. The higher the tower, the larger the building safety zone becomes. I make sure that nobody gets into that zone. By planning and safeguarding, you can be ahead of many things by separating them in time and place. Work, for example, is known weeks in advance. If we erect a tower crane on a spot, a lifting area is created. Then teams know in advance that they cannot work there. So everyone was able to do their preparations on time.”
The crane operator
"It is a challenge to move a load as quickly as possible and to let it hang as motionless as possible so that the people below can work safely with it," says crane operator Tom de Zeeuw. "I'm doing this work for 20 years. Fifteen years ago I grumbled when a load swung a meter. Now I grumble when it swings 30 centimeters.”
Tom works in the crane up high and moves a concrete funnel to the people who cast the concrete at the top of the core. He says that you can compare the mental effort of his work with driving a car on the highway. "I have to work in a concentrated way and be alert all the time. I navigate the load between people and really need my concentration.”
Tom indicates that there are tools he works with. "Beneath a hoist supervisor with a walkie-talkie indicates how much the load has to be lowered. I have a map with wall numbers, which is also useful for navigation. There is also a camera on the crane with which I can zoom in and out. The camera is a tool to correct and navigate. You should not blindly sail on these tools but trust your gut feeling and experience.”
Finally Tom states that the highest point of the core has almost been reached. He laughingly says that he can almost shake his colleagues' hands, so to speak.
The construction site manager
Willem van Dienst is construction site manager: "The biggest challenge of this project is that everyone tells what they are going to do and that everyone does what they have said, in the broadest sense of the word. So what am I going to do and with whom, how am I going to do it and especially how am I going to do it safely. My main task is to make it run smoothly and to monitor it.”
Willem says that the builders must be able to deal flexibly with their craftsmanship and with mutual cooperation. "You have to do your work when it is really necessary. Sometimes this is possible at the agreed time, sometimes not. If the wind is strong, the work may be stopped for a few hours. You have to be able to respond to that. Or if we cast concrete in one place, you can't fasten concrete reinforcement there. Then you have to be flexible to do so elsewhere.”
Willem gets happy when everything goes according to plan. "Until now everything is going well because we have spent a lot of time and attention on preparation for building the core. So if there is a problem, you have to tackle it immediately and above all continue working. Because building the core continues, 24 hours a day, seven days a week.”
The building method is unique, with a sliding formwork, says Willem. He explains how a sliding formwork works: "We first laid a foundation. From the foundation comes rebar steel. In between we place climbing poles. A hydraulic system is attached to the climbing poles. This hydraulic system lifts the formwork every time. We lift the formwork in steps of 2.5 to 3 centimeters. In an easy stage we do this every ten minutes. In a more complex situation, it takes a little longer. For example, when placing floor edges. We have calculated that we can climb 2.40 meters in 24 hours. That is an average of 10 centimeters per hour.”
Willem also gets happy when the sliding formwork makes it to the pace they want it to make. "I get a lot of energy from that. Because we put a lot of energy into it in advance to prepare it properly. And that pays off when you actually notice that it works. And it works!
Finally, Willem explains which activities start when the highest point of the core is reached next week. "Then we start with the steel construction. This means that we place columns on the ground floor. Beams are placed over these columns and these beams then connect to the core. The core determines the stability of the EMA building.”
The foreman of the slide construction
Erwin Weis works on top of the core and is the foreman of the slide construction. We spoke to him briefly during his work: "I divide the work among the people to be able to climb with the formwork. Think of casting concrete, fastening concrete reinforcement, placing steel anchors and operating the hydraulic system. The crane operator ensures that the concrete funnel hangs in the right place. With a hose attached to the funnel, we cast concrete around the formwork.” Erwin says that they have to take into account the many openings and steel plates that are needed to be able to build the entire building.