We have "sprayed" a layer of never-fading rainbow on the steel bridge."Colored ceramic particles"

I have been in the colored pavement industry for almost ten years.

To be honest, every time I pass by the newly built steel structure landscape bridge in our city, I can't help but take a few extra glances. The bridge is indeed beautiful, but every time I see someone riding an electric bike coming down the approach bridge, especially on rainy days, my heart skips a beat - the slippery, bare metal bridge deck is no joke.

Later, our team took on a project to provide anti-slip treatment for this kind of steel bridge deck. Today, I'd like to share with you how we created a rainbow effect on the steel bridge.

Why do we "dress up" steel bridges? The client didn't understand at first

When we took on this project, the client asked us, "The bridge is already in good condition, why do we have to add a layer of something?"?

I gave him an analogy: Have you ever driven a car? Try stepping on the brake on a metal manhole cover on a rainy day?

When metal surfaces come into contact with water or frost, their friction coefficient can drop below 0.2, making them virtually like ice rinks. And these ceramic particles we laid are essentially like putting a pair of spiked sneakers on the bridge deck.

The particles we use are high-hardness, high-wear-resistant ceramic with a mesh size of 6 or above. What does "through-body" mean? It means the ceramic is of one color from inside out, and even if it gets worn, it remains the same color. This is very important for landscape bridges - no one wants the pavement to look patchy and mottled after two years, like it has ringworm.

There's another detail that many people don't know: the two-component coating we use has been specially modified, addressing the common issue of traditional materials being both hard and brittle. Steel structure bridges undergo micro-deformations due to temperature changes and vehicle loads. If the coating is too brittle, it will crack within a month or two. The layer we applied **has excellent flexibility and resistance to deformation**, allowing it to move along with the bridge no matter how it moves.

 Before construction: Clean the bridge deck thoroughly

Many people think we just sweep the dust with a broom, pour the particles on, and spread them evenly, and that's it.

It's really not.

The first thing we do upon entering the site is to give the steel structure a full-body SPA treatment: cleaning, rust removal, and polishing to thoroughly remove any oil stains, dust, and rust. After that, we apply a layer of anti-rust primer.

This step may seem unremarkable, but it is actually the most crucial part of the entire project. If the surface treatment of the steel structure is not done properly, no matter how firmly it is glued later, it will be useless, and the pieces will start falling off after a while. A senior craftsman often says, **"If you mess up at the bottom, you'll have to redo it at the top."

After treating the bridge deck, the next step is to snap lines for positioning. This step is a bit like sticking masking tape, neatly framing the area to be constructed. A few of our workers squatted on the ground, holding ink fountains to snap lines. Straight lines were drawn one after another, and the sense of order was quite therapeutic to watch.

During Construction: Follow Four Steps, Each Requiring Skill and Effort

After the preparatory work is done, the paving officially begins. The entire process is divided into four steps, which we internally refer to as "four steps to completing the road".

Step 1: Apply polyurethane material by scraping. 

The workers lined up, holding scrapers to evenly apply the transparent polyurethane glue to the prepared bridge deck. This step particularly tests the hand feeling - if the glue is applied too thinly, it won't adhere to the particles; if applied too thickly, it wastes materials and is prone to sagging. Our experienced workers can achieve a mirror-like finish with the glue, controlling the flatness to the millimeter level.

Step 2: Spread ceramic particles. 

This is the most stress-relieving step. Just after scraping the glue, we immediately sprinkle the colored ceramic particles evenly while the glue is still wet. The particles do not float on the surface, but rather **partially sink into the glue** and bond with it. Red, yellow, blue, and green particles are scattered one by one, instantly bringing color to the originally gray bridge deck.

Step 3: Remove excess particles. 

After spreading the particles, we need to wait for 4 to 5 hours for the glue to fully cure. During this time, we usually take a lunch break, catch our breath, or prepare the next batch of materials. When the time is up, the workers come on stage with brooms to sweep away the "free particles" that haven't adhered to the surface. The moment they sweep away, a flat, dense, and colorful anti-slip layer emerges. The excess particles are recycled, with no waste at all.

Step 4: Top Coat Treatment. 

The final step involves spraying a layer of transparent protective coating. This layer acts like an invisible raincoat for the road surface, firmly locking in the particles while enhancing wear resistance and durability. After spraying, the entire road surface appears brighter and shinier.

04 Quality inspection: We have our own bottom line

After finishing the work, whether we can hand it over or not is not up to us, but rather depends on the instruments.

Pull test: Attach a disc to the road surface and pull it up with force to measure how tightly the particles are adhered. If the result is below the standard value, rework directly.

Ruler inspection: Place a two-meter-long ruler on the road surface and observe the size of the gap underneath. If the flatness is not qualified, start over.

Tilt friction tester: Simulates the friction between the sole of a shoe and the road surface to measure the anti-slip coefficient. If the value is insufficient, add an additional layer.

We have an internal rule: we conduct our own acceptance check before the client does. Over the years, the number of reworked projects is countable, not because of good luck, but because we keep a close eye on every step.

05 Only after entering this field did I realize: the scenery beneath our feet is also worth cherishing

To be honest, our profession is quite tiring. We're exposed to the wind and sun, running around outside all year round. But every time I see the roads I paved being trod underfoot, I still feel a bit proud.

Especially, there was one time when an elderly lady was leading her grandson across the bridge we had just completed. The child squatted down, touched the bridge surface, and turned to his grandmother, saying, "Grandma, look, there's a rainbow on the ground."

At that moment, I felt that what we were laying down was not just a non-slip layer, but also a road with warmth.

Applying ceramic particles to steel structure bridges may sound like a technical task, but ultimately, it's about ensuring that people walking in this city have a steadier footing and a more reassured heart. From materials to construction, from inspection to delivery, every step is critical and cannot be taken lightly.

Next time you pass by a colorful bridge deck, why not take a closer look at what's beneath your feet. Those tiny ceramic particles not only bear the weight of pedestrians' steps, but also represent the dedication and seriousness of the team who crafted the pavement.

Our company has been involved in the colored pavement industry for nearly a decade. If you are interested in pavement construction or have any topics you would like to discuss, please feel free to leave a message.