GB/T 23265-2023Chopped basalt fiber for cement concrete and mortar (English PDF)

3.1 Chopped basalt fiber

The basalt fiber is cut into a certain length by a cutter so that it can be inorganic mineral fiber that is evenly dispersed in cement concrete or mortar.

3.2 Nominal diameter

It is used to indicate the diameter of basalt fiber monofilament in basalt fiber products.

3.3 Strand

A bundle of slightly bonded filaments drawn at the same time.

3.4 Plied yarn

Fibers that are made by plying two or more strands.

3.5 Moisture content

The moisture content of the strand or plied yarn measured under specified conditions, that is, the ratio of the difference between the wet mass and the dry mass of the specimen o the wet mass.

4.1 Classification of product

4.1.1 Chopped basalt fibers are classified into strand (code S) and plied yarn (code T) according to their fiber types.

4.2 Specifications and dimensions

4.2.1 The specifications and dimensions of chopped basalt fibers shall comply with the provisions of Table 1.

4.2.2 Chopped basalt fibers of other specifications and dimensions can be produced upon negotiation between the supplier and the purchaser.

6.1 Appearance quality

The chopped basalt fiber has uniform color and no surface pollution.

6.2 Dimension deviation

6.3 Performance index of chopped basalt fiber

6.3.1 The performance index of chopped basalt fiber shall meet the requirements of Table 2.

6.4 Performance index of cement concrete and mortar mixed with chopped basalt fiber

The performance index of cement concrete and mortar mixed with chopped basalt fibers shall meet the requirements of Table 3.

7.1 Appearance quality

Normal illumination, distance 0.5m, visual inspection.

7.2 Dimension deviation

7.3 Performance index test of chopped basalt fiber

7.3.1 Tensile strength

The tensile strength of the plied yarn fiber shall be measured according to the method specified in Appendix A; and the tensile strength of the strand fiber shall be measured according to the method specified in Appendix B.

7.4 Performance test of cement concrete and mortar mixed with chopped basalt fiber

7.4.1 Test environment

The test shall be carried out indoors at a temperature of 20°C±5°C. The raw materials for mixing concrete or mortar shall be transported indoors in advance and the storage time shall be no less than 24h.

7.4.2 Test materials

7.4.2.1 Cement

Cement with a P·O42.5 shall comply with the provisions of GB 175.

7.4.2.2 Sand

Medium sand with a mud content of less than 1% shall comply with the provisions of GB/T 14684.

7.4.3.1 Concrete

The mix ratio of the reference concrete and the test concrete shall be designed according to JGJ 55 and shall comply with the following provisions.

7.4.3.2 Mortar

The mass mix ratio of cement, sand and water in the reference mortar is 1:1.5:0.5. The mass mix ratio of cement, sand and water in the test mortar is 1:1.5:0.5; and the chopped basalt fiber is the recommended dosage of the test fiber provided by the client.

7.4.3.3 Measuring and mixing of concrete and mortar

The measuring and mixing of concrete and mortar shall comply with the following provisions.

7.4.4 Test piece preparation, curing and number of specimens required for testing

7.4.4.1 Concrete test piece preparation and curing shall be carried out in accordance with GB/T 50081; and the standard curing age of hardened concrete or mortar is 28 days. The test items and the number of required test pieces are detailed in Table 4.

7.4.4.2 During the test, three batches of concrete or mortar for testing one type of fiber shall be completed on the same day.

7.4.5 Concrete and mortar crack reduction factor

The concrete and mortar crack reduction factor test of shall be carried out in accordance with Appendix E of GB/T 21120-2018.

7.4.6 Hardened concrete and mortar

7.4.6.4 Concrete impact strength ratio

The concrete impact strength ratio is measured according to Appendix G of GB/T 21120-2018.

8.1 Exit-factory inspection

8.1.1 Exit-factory inspection items

It includes appearance, size, density, moisture content, and combustible matter content.

8.2 Type inspection

8.2.1 Type inspection conditions

Type inspection shall be carried out in any of the following situations:

a) When the new product or old product is transferred to the factory for trial production and identification;

8.2.2 Type inspection items

It includes all technical requirements in Clause 6.

8.2.3 Batching rules

The same as 8.1.2.

8.2.4 Sampling and sample retention

Take the batch as a unit. The sampling quantity of each batch is 2kg of Type-S fiber and 10kg of Type-T fiber. Each batch of samples is divided into two equal portions, one is inspected according to the specified items; and the other is sealed and kept for half a year in preparation for re-inspection or arbitration.

9.1 Marking

The following content shall be marked on all packages in a prominent position: product name, mark, net mass, manufacturer name, factory address, production date, this Document number, etc. If there is a trademark, it shall be marked on the product package. Labor protection tips shall be specially marked on the packaging.

9.2 Exit-factory

9.2.2 The manufacturer shall provide product instructions with the goods, which shall include product name and model, exit-factory date, main characteristics, scope of application and recommended dosage, storage conditions, usage methods and precautions. […]

9.3 Packaging, transportation and storage