SIST EN 14488-7:2006

SIST EN 14488-7:2006 is the Slovenian standard identical to EN 14488-7:2006, published by SIST. It specifies a method for determining the fibre content of sprayed concrete from either a fresh or a hardened sample, so it is used when a project needs a measured fibre content rather than a nominal mix value.

The standard covers both steel fibres and polymer fibres, but the fresh-sample method is the one applicable to polymer fibres. In practice, that means the user must choose the sampling route that matches the fibre type and the stage of the concrete.

What does SIST EN 14488-7:2006 specify?

SIST EN 14488-7:2006 specifies how to determine fibre content in sprayed concrete from either fresh concrete or concrete that has already set. It is organized into clauses 1 to 9, covering scope, references, principle, apparatus, test specimens, procedures, expression of results, test report, and accuracy.

The standard is focused on one measurement: how much fibre is present in a sampled piece of sprayed concrete. That matters because sprayed concrete can vary with depth and location, so the sample has to match the quality-control purpose.

What are the key requirements of SIST EN 14488-7:2006?

Clause 1 limits the method to sprayed concrete and distinguishes between fresh and hardened samples. It also states that the fresh-sample method is appropriate for polymer fibres, while both methods can be used for steel fibres. For practice, this means the fibre type affects which sampling route is valid.

Clause 3 sets out the principle: fibres are extracted from the sample, then fibre content is determined from fibre mass and sample volume. The reader therefore needs both a reliable volume measurement and a clean fibre mass measurement.

Clause 5 gives the specimen rules. Fresh samples may come from the basic mix, in situ material, or a test panel, while hardened samples may come from in situ material or a test panel. The standard also notes that fibre content may vary with location because of the spraying process, so the sampling location must match the purpose of the test.

Clause 5.2 requires three hardened test cores and ties their preparation to EN 14488-1 and EN 12504-1. Clause 5.3 requires three fresh test coupons and says they should be cut so that they represent the full depth of the sprayed layer where possible. In practice, this means the result should reflect the material as placed, not just a convenient sample.

Clause 6 gives two routes for measuring volume. Hardened specimens can be measured by actual dimensions or by weighing in water, and fresh coupons are measured by the weighing-in-water method. The standard therefore links the fibre-content result to density-style measurements, which means careful handling and correct immersion practice matter.

Clause 6.4 and 6.5 describe fibre recovery. Hardened specimens are crushed so the fibres can be separated, then cleaned and weighed; fresh specimens are washed so the cement and fine material can be removed. The method and weighing resolution depend on fibre type, so the lab has to distinguish steel fibres from polymer fibres before reporting.

Clause 7 gives the calculation of fibre content from fibre mass and specimen volume, and Clause 8 requires the report to identify the specimen, fibre type, method used, specimen mass, fibre mass, calculated fibre content, average value, standard deviation, and any deviation from the standard. In practice, the report must support both traceability and comparison with specification limits.

What terms does SIST EN 14488-7:2006 define?

• Method A - the procedure for a hardened sample, used when the concrete has already set and the fibres are recovered after crushing the specimen.
• Method B - the procedure for a fresh sample, used when the sprayed concrete has not reached final set and the fibres are recovered by washing out the matrix.
• Cf - the symbol for fibre content, expressed in kg/m3 after calculation from fibre mass and sample volume.
• mf - the mass of fibres extracted from the sample, measured after cleaning the recovered fibres.
• Vd - the volume of the sample before fibre extraction, obtained by dimensions or by weighing in water.
• Sprayed concrete - concrete placed by spraying, where fibre distribution can vary with depth and location.

Who uses SIST EN 14488-7:2006?

SIST EN 14488-7:2006 is used by testing laboratories, contractors, specifiers, quality managers, and project owners working with fibre-reinforced sprayed concrete. They use it to check whether a placed material has the fibre content needed for quality control, acceptance checks, or compliance with a project specification.

It is especially relevant where fibre type matters, because the document treats polymer fibres and steel fibres differently. That makes the standard useful when a buyer or engineer needs a common test method for inspection and acceptance.

Which standards are used with SIST EN 14488-7:2006?

• EN 12350-6 - used for density of fresh concrete and for the weighing-in-water method for fresh specimen volume.
• EN 12390-7 - used for density of hardened concrete and for hardened specimen volume by actual dimensions or weighing in water.
• EN 12504-1 - used for cored specimens and their testing, supporting hardened sample preparation.
• EN 14488-1 - used for sampling fresh and hardened sprayed concrete and for the hardened core requirements.

The foreword also places this part within the EN 14488 series, alongside parts covering sampling, compressive strength, flexural strengths, bond strength, energy absorption, and thickness.

What does the SIST EN 14488-7:2006 document contain?

The document contains two test routes, one for hardened samples and one for fresh samples, with separate specimen preparation and fibre-recovery steps for each. It also gives the apparatus needed for weighing and immersion, including a water tank at controlled temperature and a suitable cutting tool for fresh material.

Clause 6 provides the practical procedures for measuring specimen volume and extracting fibres, and Clause 7 gives the calculation for fibre content. Clause 8 defines what the test report has to record, and Clause 9 states that there are currently no accuracy data for the test.