Joint Free Slabs

The SteelX Liberty™ Slab is a jointless slab system that completely eliminates saw cut joints while reducing slab thickness by 20%. Using 18 kg/m³ of SteelX 5:25 combined with conventional mesh reinforcement (0.15–0.25%), shrinkage stress is redistributed throughout the section — resulting in smaller, more tightly spaced cracks instead of wide random cracks at joints.

SteelX 5:25E5 Internal Cure

The Challenge

Saw cut joints are the weakest point in any concrete slab. They curl, spall, and deteriorate under forklift traffic, requiring costly ongoing maintenance. Traditional joint spacing of 4–6 metres means dozens of joints per floor — each one a potential failure point that impacts floor flatness, hygiene, and durability. Joint sealing, repair, and re-levelling represent significant lifetime costs.

Our Approach

The Liberty™ Slab eliminates all saw cut joints using a hybrid reinforcement system: 18 kg/m³ of SteelX 5:25 combined with conventional mesh at 0.15–0.25% steel ratio. The design philosophy rests on three foundations: (1) elastic slab design is the safest, most durable approach for slabs on ground, (2) the SteelX + mesh combination provides an equivalent reinforcement ratio of 0.5% that redistributes shrinkage stress into smaller, tightly spaced cracks, and (3) SteelX enhances the modulus of rupture, enabling a 20% slab thickness reduction. Only construction joints are permitted — no saw cuts allowed. Slabs up to 30 m with aspect ratio ≤ 1.5 use 0.15% steel; longer or restrained slabs use 0.25%.

Key Benefits

Complete elimination of all saw cut joints — only construction joints remain

20% slab thickness reduction through enhanced modulus of rupture

No joint sealing, no joint maintenance, no joint spalling

Improved floor flatness and aesthetics across large pour areas

Controlled crack widths through distributed hybrid reinforcement

Easy to pump and easy to finish — standard construction practices apply

Slabs up to 30 m long (aspect ratio ≤ 1.5) with 0.15% steel; longer slabs with 0.25%

Galvanised SteelX 5:25 — corrosion resistant for wash-down, bunded, and exposed environments

How It Works

Slab thickness is designed using elastic method with enhanced modulus of rupture

SteelX 5:25 is dosed at 18 kg/m³ and mixed directly into the concrete at the batching plant

Conventional mesh (SL62–SL92) is placed in the top third or top and bottom for larger slabs

Construction joints are laid out per pour size and restraint — no saw cuts permitted

Dowels are required at all formed joints; armoured joints recommended for wheeled traffic

3N16 × 1800 mm diagonal bars placed at all re-entrant corners

Concrete is cured for minimum 14 days — E5 Internal Cure recommended as standard curing method

Liberty™ Slab Design Parameters

18 kg/m³ SteelX 5:25 + conventional mesh — enhanced MOR

Slab Condition	SteelX 5:25 Dosage	Conventional Steel Ratio
Unrestrained slab ≤ 30 m, aspect ratio ≤ 1.5	18 kg/m³	0.15%
Restrained slab, > 30 m, or aspect ratio > 1.5	18 kg/m³	0.25%

Concrete Strength

f'c = 30–40 MPa

Max Shrinkage Strain

700 × 10⁻⁶

W/C Ratio

≤ 0.50

Min Curing

14 days

Conventional Steel Area Requirements

Required area of steel (mm²/m) for Liberty™ Slab thicknesses

Slab Thickness	0.15% (mm²/m)	Mesh Ref	0.25% (mm²/m)	Mesh Ref
150 mm	225	SL82	375	SL102
180 mm	270	SL92	450	SL81
200 mm	300	SL92	500	2×SL92
230 mm	345	SL102	575	2×SL92
250 mm	375	SL102	625	2×SL102
300 mm	450	SL81	750	2×SL102

For areas over 454 mm²/m (SL81), use 2 layers of mesh. Mesh placed in top third (single layer) or top and bottom (double layer).

Thickness Reduction — Enhanced MOR

Enhanced modulus of rupture at 18 kg/m³

Worked Example: 32 MPa concrete, 18 kg/m³ SteelX 5:25

Plain MOR

3.96 MPa

Liberty™ MOR

5.11 MPa

Base thickness

180 mm

Liberty™ thickness

160 mm (−11%)

Liberty™ Design Philosophy

Elastic Design

Elastic slab design is the safest, most durable design approach for a slab on ground — the slab remains within its elastic range under service loads.

Hybrid Reinforcement

SteelX + mesh provides an equivalent reinforcement ratio of 0.5%, redistributing shrinkage stress into smaller, more tightly spaced cracks — eliminating the need for saw cut joints.

Enhanced MOR

SteelX provides enhanced material properties that reduce slab thickness by 20% through improved modulus of rupture — while maintaining full load performance.