For jointless internal ground-supported slabs in automated high-bay logistics facilities, SikaFiber Force 50 is introduced at 3.0 kg/m³ to 4.0 kg/m³ where the structural brief requires crack-width control under racking uplift, side-loading forklift traffic, and early-age plastic shrinkage without continuous steel mesh. The fibre is a 50 mm embossed macro-synthetic classification under EN 14889-2:2006, Class II, intended for mechanical anchorage in cementitious matrices during slab bending rather than for replacement of primary steel in suspended spans. The concrete mix is typically specified as C30/37 or C35/45 with a maximum aggregate size of 20 mm, a water-cement ratio of 0.45 to 0.50, and a target slump of 150 mm to 180 mm for laser-guided screed placement. At the batch plant, fibre is dosed by a calibrated weigh-belting or screw-fed dispenser after coarse aggregate charging and before water addition; the mixing cycle in a twin-shaft compulsory mixer is extended by 30 s to 45 s compared with plain concrete to achieve complete dispersion. On ready-mixed deliveries, the addition of the full bag dosage into a truck mixer at a drum speed of 10 rpm to 12 rpm for a minimum of 5 min after the last fibre is accepted practice, provided the slump is not below 140 mm. The presence of the embossed fibre lowers bleed water mobility, and under high evaporation conditions above 0.50 kg/m²/h the surface may form a crust before the first power-trowel pass; the corrective sequence is to apply a certified evaporation retardant or fine misting and to postpone pan-floating by 20 min to 30 min. Ride-on power trowels fitted with 900 mm pan floats produce a closed surface without fibre protrusion when the first pass is carried out at a surface moisture condition corresponding to a footprint depth of 2 mm to 3 mm. The end product is a 150 mm to 250 mm thick jointed floor slab, with saw-cut spacing extended to 6 m to 9 m on low-friction sub-bases and residual flexural strength ratio determined by ASTM C1609/C1609M on beam specimens of 150 mm × 150 mm × 500 mm at 28 days. The specification boundary is explicit: macro-synthetic fibre does not replace mesh or bar reinforcement in pile-supported slabs, mezzanine beams, or areas where a racking leg point load exceeds 45 kN per leg; those zones require a separate reinforced pedestal or local steel cage.

What Abrasion Exposure Justifies a 4.5 kg/m³ Macro-Synthetic Addition in Container Terminal Paving?

Container terminal and intermodal yard paving experience a damage combination of static loaded containers, twist-lock induced point abrasion, reach-stacker axle loads exceeding 120 kN per axle, and occasional spillage of fuel and hydraulic oil. In this application, the concrete specification generally moves to a C40/50 or C45/55 mix with a maximum aggregate size of 25 mm, an air content controlled between 2 % and 4 % for frost resistance, and a cement content of at least 360 kg/m³. SikaFiber Force 50 is added at 4.0 kg/m³ to 5.0 kg/m³, with the higher value selected when the pavement includes embedded rail tracks or high-frequency crane travel at corners. The fibre is dosed directly into a twin-shaft compulsory mixer at the batch plant; the mixing cycle after fibre addition is extended to 60 s total wet mixing so that no fibre clusters remain in the paste phase. Placement is by a slipform paver with high-frequency vibrators set to 8,000 vpm to 12,000 vpm and a paver speed below 1.2 m/min to maintain edge stability. Dowel insertion and tie-bar placement proceed without interference because the fibre length of 50 mm is below the 140 mm to 180 mm slab thickness, but the dowel inserter hydraulic pressure is raised by approximately 10 % to ensure penetration through the fibre-reinforced matrix. The finished surface is specified with a heavy-duty power trowel or a burlap drag followed by a curing compound meeting ASTM C309, because macro-synthetic fibres increase surface water retention and reduce bleed, making early curing more critical. Abrasion resistance is verified by ASTM C779/C779M procedures; a mass loss below 0.05 % after 60 min is normally required for container terminals with steel-wheeled equipment. The end product is a jointed or continuously reinforced concrete pavement of 180 mm to 280 mm thickness, capable of sustaining 45 t reach-stacker wheel loads without surface spalling, but slabs over weak subgrade with a plate load modulus below 0.05 N/mm³ require a cement-stabilised sub-base or additional thickness because the synthetic fibre solely controls post-crack integrity and does not increase flexural capacity in uncracked sections.

When wet-mix shotcrete is applied as a temporary lining in sequential excavation or as a permanent lining in rock tunnels, the fibre addition is typically 5.0 kg/m³ to 6.0 kg/m³, and the concrete mix is designed to C32/40 or C35/45 with a maximum aggregate size of 8 mm to 10 mm, a water-cement ratio of 0.45 to 0.50, and a slump of 180 mm to 220 mm before accelerator addition at the nozzle. The embossed macro-synthetic fibre is added at the batching stage or via a volumetric dosing unit on the shotcrete rig, and the mixing pass in the truck or pan mixer must be no less than 5 min after fibre addition to avoid balling in the pump hopper. Feeding a piston pump with a 100 mm to 125 mm delivery line and a nozzle air pressure of 6 bar to 8 bar is standard; the fibre length of 50 mm passes through the reducer sections without blocking when the aggregate grading is controlled to pass a 4 mm sieve and the pump stroke rate is kept above 20 strokes/min. Rebound values rise when the fibre dosage exceeds 6.0 kg/m³ or when the accelerator dosage exceeds 5 % by weight of cement; field rebound is recorded in the range of 15 % to 25 % on overhead sections and 10 % to 15 % on vertical walls. The embossed surface of the fibre provides mechanical interlock after the first cracking event, and round panel tests conforming to ASTM C1550-20 or EN 14488-5 are used to verify energy absorption at 40 mm central deflection; the acceptance value is set from the ground class and lining design rather than from a universal product property, and published data for this specific product configuration is limited. The end product is a sprayed concrete lining of 80 mm to 150 mm thickness applied in sequential excavation rounds, with the macro-synthetic fibre replacing welded wire mesh in ground conditions classified as Q-system 0.1 to 1.0 and in temporary headings where re-entry time is governed by early strength development measured by penetration needle to 1 N/mm² or by stud driving at 0.2 N/mm². The limitation is explicit: in permanent linings subject to high rock pressure or in zones of squeezing ground, structural steel ribs and double lattice girders remain the primary load-bearing system; the fibre only improves ductility and crack distribution in the sprayed matrix and does not serve as a replacement for rock bolts or cast-in-situ secondary lining.

Demoulding Cycle Compression in Precast Wall Panels Containing Embossed Polyolefin Fibres

Precast architectural or structural sandwich wall panels are produced with the addition of 3.0 kg/m³ to 4.0 kg/m³ of macro-synthetic fibre to reduce edge spalling during demoulding, lifting, and transport. The precast mix is commonly a self-compacting or high-flow concrete with a slump-flow class of SF2 to SF3, a water-cement ratio of 0.38 to 0.42, and a maximum aggregate size of 12 mm to 16 mm. Fibre addition into a planetary or twin-shaft high-shear mixer must follow aggregate charging; the dispersive mixing phase is held for 45 s to 60 s after the fibre bags are introduced. Mould filling is by overhead skip or by a casting machine with a discharge gate aperture of 75 mm or larger to avoid fibre bridging at the hopper. The panel is consolidated on a table vibrator at 3,000 vpm to 6,000 vpm for 20 s to 40 s, and the fibre reduces rebound segregation at the mould face because the embossed filaments increase plastic viscosity. Demoulding may take place when the matrix reaches a compressive strength of 12 N/mm² for tilt-up panels and 15 N/mm² for long-line prestressed elements, measured on companion cubes according to EN 12390-3. The end product is a precast element with sharper corners, reduced breakage rates in the yard, and no exposed steel mesh that could initiate corrosion under EN 13369:2023 and EN 14992. Thermal curing at 50 °C to 60 °C for 8 h to 10 h is not altered by the fibre, but the heating ramp should not exceed 15 °C/h because macro-synthetic fibre at dosages above 4.0 kg/m³ can reduce pore connectivity and increase the risk of surface pop-outs when residual moisture is rapidly vaporised. The specification remains limited to precast elements where the fibre is used for handling stress and secondary crack control; in prestressed beams, hollowcore units, or load-bearing shear walls with high seismic ductility demands, the fibre is supplementary and does not replace welded wire reinforcement or prestressing strand.

On trapezoidal metal deck profiles of 0.75 mm to 1.20 mm base metal thickness, the mezzanine slab topping is commonly a C30/37 or C35/45 concrete with a maximum aggregate size of 10 mm, a water-cement ratio of 0.42 to 0.48, and a slump of 160 mm to 200 mm. SikaFiber Force 50 is added at 3.0 kg/m³ to 4.0 kg/m³ to control plastic shrinkage cracking over the deck ribs and to improve residual tensile strength between shear stud rows. The fibre is discharged into a truck mixer after the concrete is batched, and the drum is rotated at 12 rpm for 5 min per cubic metre of load; a slower drum speed below 8 rpm leaves visible fibre bundles in the placed concrete. Pumping uses a 125 mm diameter boom pump with a steel line restriction not below 100 mm; the tip hose is kept below 18 m length to reduce line pressure spikes. Placement starts from the low end of the deck and advances toward the supporting beams, with the fibre-reinforced topping compacted by a screed vibrator or a twin-beam roller to avoid air pockets behind deck ribs. The finish is left bull-floated rather than hard-trowelled because a tight trowel finish over macro-synthetic fibre can raise surface filaments and reduce the bond for subsequent resin flooring. The end product is a composite slab topping of 75 mm to 150 mm above deck ribs, integrating with headed stud shear connectors to form the compression flange of the steel-framed mezzanine; however, the fibre does not alter the composite section’s positive-moment flexural capacity and the metal deck remains the primary tensile reinforcement for negative moments over girders. Fire resistance is assessed under EN 1994-1-2 or UL 263, and the use of macro-synthetic fibre is secondary to the specified concrete cover and stud height; it is not permitted to reduce the minimum topping thickness of 65 mm measured above the deck profile.

When Ammonium Lactate Leachate Drives Surface Deterioration in Feedlot Slabs

Agricultural traffic slabs, silage clamps, and effluent collection aprons are exposed to a chemically aggressive environment dominated by lactic acid, acetic acid, and ammonium lactate. In these use cases, a C35/45 concrete with a maximum aggregate size of 20 mm and a water-cement ratio not exceeding 0.45 is specified, and SikaFiber Force 50 is added at 4.0 kg/m³ to 5.0 kg/m³. The polyolefin-based embossed fibre is inert to the acid and salt load, and unlike steel fibre it introduces no corrosion risk in the surface zone when the slab is repeatedly hosed down. Mixing is carried out in a twin-shaft batch mixer with a wet mixing time extended by 30 s to 60 s after fibre addition; using a central mixing plant rather than site dosing is preferred because wind-driven fibre loss from torn bags at the edge of a silage clamp is a known batch-to-batch variance source. Placement is by direct discharge and manual screed, or by a small slipform paver for feed alley kerbs, followed by a roller screed and a light float pass. A burnished finish is not desirable; the surface is left with a wood-float or broom finish to give livestock traction and to avoid burnishing the macro-synthetic filaments into the paste. Curing under EN 13670 and protection against frost at early age follow the same rules as plain concrete, with the exception that the fibre-reinforced slab must not be overwatered to bring back a lost bleed surface; overwatering weakens the top 10 mm and promotes spalling under hoof traffic. The end product is a 120 mm to 180 mm thick slab with improved resistance to impact, thermal cycling, and manure slurry cleaning; but for silage clamp walls where hydrostatic pressure from retained silage exceeds 5 kN/m², conventional reinforced concrete with steel reinforcement remains mandatory, and the macro-synthetic fibre is confined to the floor apron only, not to structural walls.