Test method of cement mortar strength (ISO method)
1 Scope
This document specifies the principles, laboratory and apparatus, mortar constituents, preparation of mortar, preparation of test specimens, conditioning of test specimens, test procedures, test results, validation testing of China ISO standard sand and of alternative equipment of test method of cement mortar strength (ISO method).
This document is applicable to the flexural and compressive strength tests of common Portland cement, limestone Portland cement mortar, and to other cements and materials, the standards for which call up this document. It might not applicable to the strength tests of other cement mortar types that have, for example, a very short initial setting time.
2 Normative references
The following referenced documents are indispensable for the application 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 6003.1 Test sieves - Technical requirements and testing - Part 1: Test sieves of metal wire cloth (GB/T 6003.1-2012, ISO 3310-1:2000, MOD)
GB/T 6682 Water for analytical laboratory use - Specification and test methods (GB/T 6682-2008, ISO 3696:1987, MOD)
JC/T 681 Mixer for mixing mortars
JC/T 682 Jolting table for compacting mortars specimen
JC/T 683 40 mm x 40 mm Jig for cement compressive strength test machine
JC/T 723 Cement mortar vibration compaction equipment
JC/T 724 Electrically driven flexure testing device for strength of cement mortar
JC/T 726 Mould for cement mortars
JC/T 959 Curing box for cement mortar specimens
JC/T 960 Automatic compression machine for testing cement strength
3 Terms and definitions
No terms and definitions are listed in this document.
4 Principles
This method is comprised of a determination of the compressive, and optionally the flexural, strength of a prismatic test specimen 40 mm × 40 mm × 160 mm in size.
These specimens are cast from a batch of plastic mortar containing one part by mass of cement, three parts by mass of Chinese ISO standard sand and one half part of water (water/cement ratio of 0.50). Chinese ISO standard sands from various sources and countries may be used, provided that they have been shown to give cement strength results that do not differ significantly from those obtained using the ISO reference sand (see Clause 12).
In the reference procedure, the mortar is prepared by mechanical mixing and is compacted in a mould using a jolting apparatus. Alternative compaction equipment and procedures may be used provided that they have been shown to give cement strength results that do not differ significantly from those obtained using the reference jolting apparatus and procedure (see Clause 12).
Foreword II
1 Scope
2 Normative references
3 Terms and definitions
4 Principles
5 Laboratory and apparatus
5.1 Laboratory
5.2 Moist-air cabinet
5.3 Storage container
5.4 Cement, Chinese ISO standard sand, and water used for tests
5.5 Test sieves, wire cloth
5.6 Equipment
6 Mortar constituents
6.1 Sand
6.2 Cement
6.3 Water
7 Preparation of mortar
7.1 Composition of mortar
7.2 Mixing of mortar
8 Preparation of test specimens
8.1 Size and shape
8.2 Moulding
9 Conditioning of test specimens
9.1 Handling and storage before demoulding
9.2 Demoulding
9.3 Curing of specimens in water
9.4 Age of specimens for strength tests
10 Test procedures
10.1 Flexural strength test
10.2 Compressive strength test
11 Test results
11.1 Flexural strength
11.2 Compressive strength
12 Validation testing of Chinese ISO standard sand and of alternative equipment
12.1 General
12.2 Validation testing of Chinese ISO standard sand
12.3 Validation testing of alternative compaction equipment
