A 3.5 m urban screen on 175×175 H-steel posts, combining metal louver absorptive panels, transparent acrylic and perforated panels — built around daylight, streetscape and buried municipal services.
Urban barriers are won or lost on interface, not just acoustics. The BRT corridor used absorptive louvers to stop reflected noise hitting opposite buildings, transparent acrylic to keep daylight and sightlines for residents, and a single 175×175 H-steel post system to unify the wall. Success depended on early coordination with municipal utilities so posts and foundations avoided live services.
A bus rapid transit (BRT) corridor concentrates frequent, accelerating and braking traffic next to shops, apartments and sidewalks — the worst-case receiver geometry for road noise. The project needed a continuous screen along the corridor that would cut noise for adjacent buildings without turning the street into a closed-in trench or blocking the daylight that makes ground-floor space usable. Zhaobang Metal supplied the barrier material package: metal louver absorptive panels, transparent acrylic (PMMA) panels and perforated metal panels on a 175×175 H-section steel post system, plus shop drawings and acoustic data. On-site construction was performed by the contractor and EPC, not by Zhaobang. Total screened length followed the corridor alignment and is recorded on the projects page.
| Parameter | Supplied specification |
|---|---|
| Location | Urban Bus Rapid Transit (BRT) corridor, city arterial |
| Total barrier length | Defined by corridor alignment (segmented by station frontages) — see project record |
| Barrier height | 3.5 m |
| Post system | 175×175 H-section steel columns |
| Panel system | Metal louver absorptive panel + transparent acrylic (PMMA) board + perforated metal panel |
| Acoustic target | Panels specified to JT/T 646-2025: Rw ≥ 26 dB (non-transparent), NRC ≥ 0.60 (absorptive), generally aligned with the corridor's insert-loss expectation |
| Corrosion protection | Hot-dip galvanized posts + powder-coated panels (RAL), typical C3 urban environment |
| Project role | Material supply (panels, posts, accessories), shop drawings, acoustic data; erection by local contractor |
Daylight and streetscape. A solid 3.5 m wall along a city street can darken ground-floor windows and make the public realm feel enclosed. Transparent acrylic panels were used along residential frontages and at station areas so light and sightlines were preserved while the direct source–receiver path stayed blocked.
Reflected noise on both sides. Unlike an open highway, a city road has occupied buildings on both sides. A reflective panel would bounce noise toward the opposite sidewalk and facades, so the bulk of the wall used absorptive louver panels that absorb sound on the source side instead of returning it across the road.
Buried and overhead utilities. The corridor shared the verge with water, gas, power, street lighting and communication services. Post positions and foundation depths had to be planned around live services, which is a discipline in its own right in a dense urban corridor.
Metal louver absorptive panel. The primary noise-control element: a perforated metal face over a mineral-wool or fibre-composite core. It absorbs incident sound on the road side, reducing reflection and reverberation, and reaches NRC 0.80–0.95 typical — above the NRC ≥ 0.60 requirement in JT/T 646-2025. The metal face also resists vandalism and is easy to wash.
Transparent acrylic (PMMA) board. Used where the street needed openness: station forecourts, residential frontages and intersections. It is impact-rated and UV-stabilised and mounts on the same 175×175 H-post system, so the transparent and metal runs form a single continuous barrier.
Perforated metal panel. A perforated, generally absorptive metal module used to vary the architectural rhythm and provide additional source-side absorption. All three share the post system and fixing accessories. See the noise barrier specifications page for the full construction reference and the noise barrier product page for the supply envelope.
Records review and marking. Before any post was located, the utility records for the corridor were reviewed and the known buried and overhead services were marked out, turning an invisible risk into a drawn line on the layout.
Post and foundation adjustment. Where a planned post conflicted with a live duct or cable, the post position was shifted or the foundation depth adjusted so cast-in anchors and excavations kept a safe clearance. Where a post had to sit near a service, the relevant utility owner was consulted.
Joint ownership. This mapping is generally done together with the municipal departments and the contractor before foundation works begin, because a struck service stops the whole corridor. Treating utility coordination as a design input — not a site surprise — is the single biggest schedule protector on an urban barrier job. For the erection sequence see the noise barrier installation guide.
The supplied package delivered a continuous 3.5 m screen along the BRT corridor on a single 175×175 H-steel post system. Panels were accepted against the project's acoustic and structural requirements: non-transparent and absorptive panels specified to meet or exceed JT/T 646-2025 (Rw ≥ 26 dB for non-transparent panels, NRC ≥ 0.60 for absorptive panels), with the post system verified for the urban wind load under GB/T 51335-2018.
Because the louver, transparent and perforated modules share one post system, the wall presents as a single continuous barrier with a varied, lighter streetscape rhythm. Acceptance generally followed visual and dimensional inspection plus acoustic spot checks against the HJ/T 90-2004 design insert-loss target. Comparable work is listed on the projects page.
In a city, a solid 3.5 m wall can feel like a prison frontage and can darken ground-floor windows and streets. Transparent acrylic (PMMA) or polycarbonate modules restore daylight and sightlines for residents and pedestrians while still blocking the direct source–receiver path. On the BRT corridor the transparent sections were placed along residential frontages and at station areas where openness matters. The transparent and metal modules share the same H-post system, so the wall stays continuous and the acoustic break is unbroken even where you can see through it.
Urban corridors are crowded with buried and overhead services — water, gas, power, street lighting, signal and communication ducts. Before posts are located we review the utility records and mark out conflicts, then shift post positions or adjust foundation depth so cast-in anchors and excavations avoid live services. Where a post must sit near a duct, we coordinate with the utility owner on safe clearance. This utility mapping is generally done jointly with the municipal departments and the contractor before any foundation work begins.
A metal louver (perforated) absorptive panel has a sound-absorbing core behind a perforated face, so it soaks up sound on the source side instead of bouncing it back across the road toward buildings on the opposite side. That is exactly what you want in a city where both sides of the road are occupied. Our standard absorptive panels reach NRC 0.80–0.95, above the NRC ≥ 0.60 baseline in JT/T 646-2025, while the metal face resists vandalism and is easy to wash down — a practical choice for a busy urban corridor.