Home > PB28A-3R-II Column-Climbing Concrete Placing Boom — 27.7 m Radius

PB28A-3R-II Column-Climbing Concrete Placing Boom — 27.7 m Radius

The PB28A-3R-II is a column-climbing concrete placing boom — a self-climbing, fully hydraulic boom that distributes concrete across a high-rise floor and climbs the building itself as the structure rises. It places concrete over a 27.7 m radius through a 3-section R-fold boom that slews a full 360°, fed by a separate concrete pump up a riser pipeline. Rather than being towed or truck-mounted, this internal-climbing placing boom sits on a floor frame or inside an elevator shaft / core wall and lifts itself up floor by floor, which is what makes it the standard tool for concreting tall building cores and shear walls.

A placing boom is not a pump: it is the placing end of the high-rise concreting system. A stationary or line concrete pump pushes concrete up the riser, and the PB28A-3R-II distributes it precisely across the deck — reaching places a pump pipeline alone cannot. Built and tested in our own factory in Haining, it runs on a 380V/50Hz supply with an 11 kW motor and is backed by ISO 9001:2015 and CE certification and service in more than 120 countries. TRUEMAX placing booms are a flagship export line, used on projects from Shanghai high-rises to towers in the UAE and Chile.

1. Self-climbing (floor or shaft frame) — Climbs the building internally on a floor frame or inside the elevator shaft / core wall, rising with the structure — no external crane lift between floors.

2. Light weight, easy on floor loading — The whole machine is light, which is kinder to floor and slab loading, and the lifting-unit weight is greatly reduced, so a smaller site crane can install and relocate it.

3. No balance arm — Without a balance arm, the boom slews more freely in the confined space of a core or floor.

4. Full 360° gear slewing with cushion valve — Gear slewing gives full rotation, and a slewing cushion valve smooths start and stop for steady, controlled placing.

5. 3-section R-fold boom (3R) — The fully hydraulic R-fold boom opens and closes flexibly for a wide 27.7 m placing range, and folds compactly for climbing and transport.

6. Integrated pump station + control cabinet — The hydraulic pump station and electric control cabinet are integrated on the lower support, which speeds on-site installation and lowers the failure rate.

7. Multiple remote-control options — Operate by TRUEMAX electric-proportional remote, or switch-type radio and cable remotes, built with Omron / Schneider electrical components.

8. Quality build, customisable columns — Imported hydraulic hose and push-in connectors throughout; columns can be specified in 4 m, 5 m, 6 m or 10 m lengths with floor or shaft climbing frames to suit the structure.

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Technial Parameters

Item	Unit	PB28A-3R-II
Performance
Max. Radius of Placing Boom	m	27.7
Free-Standing Height (to boom root joint)	m	21.3
Slewing Range	/	360°
Mode of Slewing	/	Gear Slewing
Circumstance Temperature	℃	-20 ~ 55
Power Supply (customisable)	/	380V / 50Hz
Boom (3-Section R-Fold)
1st Section — Length	m	10.5
1st Section — Articulation	°	0 ~ 86
2nd Section — Length	m	9.2
2nd Section — Articulation	°	0 ~ 180
3rd Section — Length	m	8
3rd Section — Articulation	°	0 ~ 180
Delivery Line
Delivery Pipeline Diameter	mm	Φ125 × 4.5
Delivery Hose Diameter	in × mm	5" × 3000
Power & Hydraulics
Motor Power	kW	11
Hydraulic Pressure	MPa	28
Hydraulic Oil (5℃–55℃)	/	HM46 anti-wear
Hydraulic Oil (-20℃–5℃)	/	HM32 anti-wear
Installation & Weight
Application Scenario	/	Floor / Shaft Climbing
Balance Arm	/	None
Total Weight	kg	16200
Max. Lifting Unit	kg	4100

Dimensions & Working Range

The working-range diagram shows the area the PB28A-3R-II can place concrete across from a single position — the 27.7 m radius swept through a full 360°, plus the vertical envelope of the folding boom. The free-standing height of 21.3 m is the height the boom stands above its support without external bracing. Read the diagram with the climbing-frame and column drawings to plan the installation in your core or on your floor.

Applications

The PB28A-3R-II is built for tall structures where the placing boom climbs with the building and distributes concrete across each floor as it is poured.

High-rise building cores and shear walls

As a column-climbing placing boom, it sits in the core or on a floor frame and rises with the structure, placing concrete across the deck, walls and columns over a 27.7 m radius — the standard way to concrete a high-rise tower floor by floor.

Elevator shafts and core walls

With a shaft frame, the boom climbs inside the elevator shaft or core wall, ideal for buildings where floor space is tight and the core leads the construction.

Bridge pylons and tall piers

The self-climbing principle also suits tall bridge pylons and piers, where the boom climbs the rising element and places concrete without a crane lift for each pour — TRUEMAX placing booms are used on major bridge projects.

Paired with a concrete pump

On every job the PB28A-3R-II works with a separate stationary or line concrete pump that feeds concrete up a riser; the placing boom then distributes it precisely, reaching across the floor where the pump line alone cannot.

FAQs

What is a column-climbing placing boom?

It is a self-climbing concrete placing boom that climbs the building internally — on a floor frame or inside the elevator shaft / core wall — and rises with the structure as it is built. The PB28A-3R-II distributes concrete over a 27.7 m radius across each floor, so the boom moves up with the tower instead of being lifted by crane between pours.

Is the placing boom a concrete pump?

No. A placing boom is the placing end of the system, not the pump. A separate stationary or line concrete pump pushes concrete up a riser pipeline, and the PB28A-3R-II then distributes it across the floor through its 3-section boom. They are used together on high-rise concreting.

How does it climb the building?

With a climbing frame: a floor frame for floor-by-floor climbing, or a shaft frame for climbing inside an elevator shaft or core wall. The boom lifts itself up its own standing height as the structure rises, which removes the crane lift that a non-climbing boom would need for each level.

What radius and how many boom sections does it have?

The PB28A-3R-II reaches a 27.7 m placing radius with a 3-section R-fold boom (the “3R” in the model name), and slews a full 360°. The three sections are 10.5 m, 9.2 m and 8 m, which sum to the 27.7 m radius.

Is it electric or diesel?

Electric — it runs on a 380V/50Hz supply with an 11 kW motor (voltage and frequency can be customised to your market), so it can run off site power or a generator. It has no diesel engine of its own; the concrete is supplied by a separate pump.

What crane capacity is needed to install it?

The maximum single lifting unit is 4,100 kg, which is the heaviest individual piece a crane must lift during assembly — the modular design and reduced lifting-unit weight keep the required site crane capacity low. The total installed weight is 16,200 kg.

What is included, and how is it delivered?

The standard package is the placing boom with its lower support, hydraulic pump station, control cabinet and remote control. Columns (4/5/6/10 m), floor or shaft climbing frames, delivery pipeline and hose, spare-parts kits, installation and commissioning are specified and quoted to your project. Tell us your building and we will confirm the configuration and lead time.

Where the PB28A-3R-II fits in the TRUEMAX placing-boom range

The PB28A-3R-II is the 27.7 m model in the TRUEMAX column-climbing placing-boom line, which also includes the 31.7 m PB32A-3R-II, the 32.4 m PB33A-4R-II, the 32.55 m PB33B-4R and the 35 m PB35A — choose the radius that covers your floor plate. The full B8 placing-boom range offers six types in all: column-climbing (self-climbing for cores), formwork-climbing, spider (mobile), mobile spider (wheeled), lattice tower (free-standing on a mast), and the Truemax-specialty mobile boat boom for over-water work. The column-climbing type is the choice when the boom needs to climb a tall structure internally.

How a placing boom works with a concrete pump

A concrete placing boom is the final link in the high-rise concrete chain. Concrete is produced at a batching plant, hauled to site by a concrete truck mixer, and pumped up the building by a stationary concrete pump or truck-mounted line pump through a riser pipeline. At the top, the placing boom — here the PB28A-3R-II — distributes the concrete across the floor, walls and columns, reaching where the fixed pipeline cannot. Pump plus placing boom is the standard system for concreting a tower floor by floor.

Column-climbing vs other placing-boom types

A column-climbing (internal-climbing) placing boom is the right choice when a tall building core or shaft leads construction and the boom should rise with the structure. A spider or mobile placing boom is better for lower floors and slabs where the boom is moved around by crane or wheels; a lattice-tower placing boom stands free on its own mast for very tall free-standing reach; and the mobile boat boom serves over-water and bridge work. All are fed by a concrete pump and all distribute concrete — the difference is how they are supported and how they climb.