EN 14845-1:2007

Overview

EN 14845-1:2007 - Test methods for fibres in concrete, Part 1: Reference concretes (CEN) defines standard reference concretes and procedures used to evaluate the performance of steel and polymer fibres in concrete. The standard establishes mix compositions, specimen preparation, curing and reporting requirements so that comparative laboratory tests (e.g., flexural performance) are repeatable and meaningful. Its primary purpose is to determine the general suitability of a fibre for use in concrete; end users must also verify fibre effectiveness in their specific mixes.

Key topics and technical requirements

• Reference concretes: Four types are specified by target flexural tensile strength, maximum aggregate size and maximum cement content.
  • Mandatory mix example: 16 mm or 20 mm aggregate with target flexural tensile strength 4.3 ± 0.3 MPa, W/C ≈ 0.55, max cement 350 kg/m³.
  • Optional higher-strength example: target 5.8 ± 0.4 MPa, W/C ≈ 0.45, max cement 400 kg/m³.
• Materials: Use CEM I 42,5 R cement (EN 197-1), natural silica-based uncrushed aggregates with <2% water absorption, and mixing water per EN 1008. Admixtures (plasticizers/superplasticizers) are allowed per EN 934-2 to meet workability.
• Consistency / workability: Measured by Vebe test (EN 12350-3) - Vebe class V3, or compactability per EN 12350-4 - class C2. Mix must avoid segregation/bleeding.
• Mixing & specimen prep: Forced-action pan mixer; batch volume 50–90% of capacity; add half water to aggregates, mix 2 min, add cement and remaining water, total mix ≤5 min. Fibres added per manufacturer instructions to ensure even dispersion.
• Compaction & moulding: Non-absorbent rigid moulds and high-frequency vibrating table for beam moulds (tests per EN 14845-2 / EN 14651).
• Curing: 24 h in mould at (20 ± 2) °C under polyethylene or ≥95% RH, then demould and water-cure 27 days at (20 ± 2) °C.
• Reporting: Record mix composition (kg/m³), W/C, fibre description (per EN 14889-1/2), particle size, Vebe/compactability, curing, limit of proportionality (LOP) strengths to 0.01 MPa, production date/time and deviations.

Applications and users

• Fibre manufacturers validating product performance for marketing and compliance.
• Independent testing laboratories and research institutes performing comparative fibres in concrete tests (strength and workability).
• Specifiers, product certifiers and R&D teams developing fibre-reinforced concrete mixes and systems (precast, shotcrete, industrial floors, sprayed linings).
• Contractors and precast plants using laboratory reference data to inform in-house trials.

Related standards

• EN 14845-2 (effect on strength), EN 14889-1/2 (fibre definitions), EN 14651 (flexural test), EN 197-1, EN 206-1, EN 1766, EN 12350 series, EN 934-2, EN 933-2, EN 1008.

Keywords: EN 14845-1:2007, reference concrete, fibres in concrete, test methods, flexural tensile strength, water/cement ratio, mix design, specimen preparation, curing.