GB/T 7897-2026 Test methods of properties of mortar for ferrocement English, Anglais, Englisch, Inglés, えいご
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ICS 13.220.10
CCS H 57
National Standard of the People's Republic of China
GB/T 7897-2026
Replaces GB/T 7897-2008
Test methods of properties of mortar for ferrocement
钢丝网水泥用砂浆性能试验方法
Issue date: 2026-01-28 Implementation date: 2027-02-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative References
3 Terms and Definitions
4 Test Conditions
5 Specimen Preparation
6 Flexural Strength
7 Compressive Strength
8 Splitting Tensile Strength
9 Axial Compressive Strength
10 Static Modulus of Elasticity in Compression
11 Poisson's Ratio
12 Bond Strength
13 Water Absorption Rate
14 Impermeability
15 Shrinkage Performance
16 Early Crack Resistance
Bibliography
Test Methods for Performance of Mortar for Ferrocement
1 Scope
This document describes the test conditions and specimen preparation for performance testing of mortar for ferrocement, as well as test methods for flexural strength, compressive strength, splitting tensile strength, axial compressive strength, static modulus of elasticity in compression, Poisson's ratio, bond strength, water absorption rate, impermeability, shrinkage performance, and early crack resistance.
This document applies to the performance testing of mortar for ferrocement.
2 Normative References
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 17671 Test method for strength of cement mortar (ISO method)
GB/T 21389 Vernier, dial and digital display calipers
GB/T 26497 Electronic balance
GB/T 30435 Electric drying oven with or without forced ventilation
JC/T 682 Vibrating table for compacting cement mortar specimen
JC/T 683 40 mm x 40 mm jig for cement compressive strength
JC/T 723 Vibrating machine for cement mortar
JC/T 724 Electric flexural testing machine for cement mortar
JC/T 726 Mould for cement mortar specimen
JC/T 949 Release agent for concrete products
JC/T 960 Automatic pressure testing machine for cement mortar strength
JG/T 3033 Mixer for testing mortar
JGJ/T 70 Standard for test method of basic properties of construction mortar
3 Terms and Definitions
The following terms and definitions apply to this document.
3.1
ferrocement
ferrocement product
A thin-walled structural material composed of cement mortar as the matrix and steel mesh, or steel mesh and reinforcement, as the reinforcement.
[Source: GB/T 4582-1984, 1.1, modified]
4 Test Conditions
4.1 The ambient temperature during laboratory molding shall be maintained at (20 ± 5) °C, and the relative humidity shall not be less than 50%.
4.2 The ambient temperature during mechanical property testing of mortar shall be maintained at (20 ± 2) °C, and the relative humidity shall not be less than 50%. For shrinkage and early crack resistance testing, the ambient temperature in the shrinkage room shall be maintained at (20 ± 2) °C, and the relative humidity shall be maintained at (60 ± 5)%.
5 Specimen Preparation
5.1 Specimen Molding
5.1.1 When preparing mortar specimens in the laboratory, all materials used shall be placed under the test conditions specified in 4.1 for at least 24 hours.
5.1.2 When mixing mortar in the laboratory, material quantities shall be measured by mass. The weighing accuracy for cement, water, and admixtures shall be ±0.5%; the weighing accuracy for sand shall be ±1%.
5.1.3 Mechanical mixing shall be used for laboratory mortar mixing. The mixer shall conform to the requirements of JG/T 3033. Each mixing batch shall be 30% to 70% of the mixer's capacity. The mortar shall be mixed uniformly, with a mixing time of 120 s to 180 s.
5.1.4 All specimens shall be prepared immediately after sampling and completed within 30 minutes.
5.1.5 When molding specimens, use moulds conforming to JC/T 726, and apply a release agent conforming to JC/T 949 to the inner surfaces of the mould.
5.1.6 Fill the mould with the mixed mortar at one time. The molding method depends on the consistency of the mortar. The test method for mortar consistency conforms to JGJ/T 70. For mortar with a consistency between 30 mm and 70 mm, use a vibrating table to compact for 30 s to 45 s. The vibrating table shall conform to the requirements of JC/T 682 or JC/T 723. For mortar with a consistency greater than 70 mm and less than 120 mm, use manual compaction with a tamping rod. During manual compaction, use a 16 mm diameter steel rod to tamp in two layers, with 12 tamps per layer.
5.2 Specimen Curing
5.2.1 Standard curing shall be used when determining strength grades. After molding, cover the surface of specimens intended for standard curing with plastic film, cure in a curing box or curing room for 24 hours, then demold and cure in water until the strength test.
5.2.2 The specimen curing requirements shall comply with the provisions of GB/T 17671. Specimens shall be cured until the age of 28 days (counted from the time of molding) before testing.
6 Flexural Strength
6.1 Specimens
Prepare specimens according to the provisions of Chapter 5, using specimens of size 40 mm × 40 mm × 160 mm. Each group consists of 3 specimens.
6.2 Apparatus
6.2.1 The flexural strength testing machine shall conform to the provisions of JC/T 724.
6.2.2 Calipers with a division value or resolution not greater than 0.1 mm, conforming to GB/T 21389.
6.3 Test Procedure
6.3.1 Use the caliper to measure each of the four side lengths at the same cross-section in the middle of the specimen once. Calculate the arithmetic mean of the four measured values as the side length (b) of the specimen. Round the result to 0.1 mm.
6.3.2 Place one lateral side of the specimen on the supporting rollers of the flexural testing machine, with the long axis of the specimen perpendicular to the supporting rollers. Apply a vertical load uniformly on the opposite lateral side through the loading roller at a rate of (50 ± 10) N/s until the specimen breaks. Record the failure load and failure location. Keep the two half-prisms in a moist state until the compressive strength test.
6.4 Calculation and Expression of Results
6.4.1 Calculate the flexural strength of an individual specimen according to formula (1). Round the result to 0.1 MPa.
6.4.2 The test result for mortar flexural strength is taken as the arithmetic mean of the measured values from the 3 specimens in the group. If one of the three measured values exceeds the average by more than ±10%, discard this value and calculate the average of the remaining two as the flexural strength test result. If two of the three measured values exceed the median value by more than 10%, the flexural strength test result for that group is considered invalid.
7 Compressive Strength
