Based on your previous questions regarding props (scaffolding) and formwork materials, here is a focused overview of the common types of formwork and props as they function together in concrete construction.
In this context, formwork is the mold that shapes the concrete (walls, slabs, columns), while props (often called shores or falsework) are the vertical support systems that hold the formwork in place until the concrete cures.
Common Types of Formwork
Formwork is typically categorized by its material and application method.
1. By Material
| Material | Description | Best Use |
|---|---|---|
| Timber/Plywood | Traditional; uses lumber and phenolic plywood. | Foundations, complex shapes, small projects. Low initial cost, but limited reuse (3–10 cycles). |
| Steel | Prefabricated heavy-duty panels. | Large walls, columns, retaining walls. High strength, smooth finish, high reuse (100+ cycles). Heavy and requires cranes. |
| Aluminum | Lightweight modular systems (e.g., MIVAN). | Mass housing, repetitive floor plans. Fast assembly, high reuse, excellent finish. |
| Plastic/FRP | Fiberglass-reinforced plastic molds. | Curved walls, domes, textured architectural surfaces. Lightweight, smooth finish, but costly. |
2. By Application System
| Type | Description |
|---|---|
| Wall Formwork | Large crane-lifted panels (steel or aluminum) clamped together. Used for shear walls, retaining walls, and foundations. |
| Column Formwork | Prefabricated square, rectangular, or round forms with latch systems. Designed to withstand high concrete pressure during pouring. |
| Slab Formwork | Includes traditional timber joists and plywood, or modern table/flying forms (pre-assembled decks with integrated legs that are craned floor-to-floor). |
| Climbing Formwork | Self-anchoring systems that “climb” vertically using hydraulics. Used for high-rise cores, bridge pylons, and silos. |
| Slip Formwork | Continuous moving formwork that rises steadily (typically 200–300 mm/hour) while concrete is poured continuously. Used for elevator shafts and tall structures. |
Common Types of Props (Shoring / Falsework)
Props provide the vertical support for formwork, transferring the weight of wet concrete, formwork, reinforcement, and workers down to the ground or a lower cured slab.
1. Acrow Props (Adjustable Steel Props)
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Description: Telescopic steel tubes with a threaded collar and pin for fine height adjustment.
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Typical Height Range: 1.5 m to 4.0 m (extendable with couplers).
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Application: Supporting beam and slab formwork in residential and low-rise commercial construction.
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Pros: Low cost, widely available, easy to install.
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Cons: Limited load capacity; requires lateral bracing for heights exceeding 3–4 m.
2. Aluminum Shoring Frames (or “H-Frames”)
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Description: Prefabricated aluminum frames that stack vertically to form shoring towers.
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Application: High ceilings (airports, malls, auditoriums) and heavy slab loads.
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Pros: Lightweight, high load capacity, fast assembly.
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Cons: Higher initial cost; requires trained crews.
3. Heavy-Duty Steel Shoring (Post Shores)
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Description: Thick-walled steel tubes or engineered truss systems.
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Application: Bridges, heavy transfer beams, industrial foundations where loads exceed 30 kN per prop.
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Pros: Extremely high load capacity.
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Cons: Very heavy; requires cranes or specialized handling.
4. Table / Flying Shores
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Description: Integrated systems where the slab formwork deck is permanently attached to steel or aluminum legs. The entire assembly is lifted by crane and moved to the next floor as one unit.
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Application: High-rise buildings with repetitive floor plates (hotels, residential towers).
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Pros: Eliminates stripping and rebuilding; dramatically speeds up construction cycles (often 3–5 days per floor).
5. Underpinning Props (Dead Shores & Raking Shores)
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Description: Used for structural stabilization rather than concrete pouring.
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Dead Shores: Vertical props used to temporarily support a structure during foundation repairs or wall alterations.
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Raking Shores: Inclined props used to stabilize unstable walls from the outside.
How Formwork and Props Work Together
In modern construction, formwork and props are often integrated into engineered systems. Major manufacturers (such as PERI, Doka, MEVA) provide matched systems where:
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The formwork creates the precise concrete shape.
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The props (shores) are designed with specific spacing and load ratings to safely support the formwork and wet concrete.
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The falsework (horizontal beams, frames) connects the props to the formwork deck.
Example: Slab Formwork System
| Component | Role |
|---|---|
| Plywood / Steel Deck | Forms the bottom surface of the concrete slab. |
| Joists / Beams | Horizontal supports distributing load. |
| Props (Shoring) | Vertical supports transferring load to ground or lower slab. |
| Bracing | Lateral stabilization to prevent buckling. |
Quick Reference Table
| Category | Type | Key Feature |
|---|---|---|
| Formwork | Timber/Plywood | Flexible, low cost, low reuse |
| Steel Panels | High strength, smooth finish | |
| Aluminum (MIVAN) | Lightweight, fast, high reuse | |
| Climbing/Slip | Continuous or jumping for tall structures | |
| Props | Acrow Prop | Adjustable, general purpose |
| Aluminum Frame | Lightweight, high capacity for height | |
| Heavy-Duty Steel | Extreme loads (bridges) | |
| Flying Shore | Integrated with slab formwork, crane-moved |
If you have a specific application in mind—such as residential high-rise, bridge construction, or small foundations—I can offer more targeted recommendations on which formwork and prop combination would be most suitable.
