GB/T 17671-1999 Method of testing cements – Determination of strength (Text of Document is in English)

01/05/1999

18P

$150.00 USD

1 Scope

This Standard specifies instruments, materials, mortar constituents, test conditions, operation procedures and result calculation for the reference test method of cement mortar strength. The measured results of compressive strength is identical to the results of ISO 679.Alternative standard sand and compaction table is listed. Any disagreement in the results after alternation is subject to the reference method.
This Standard is applicable to the portland cement, ordinary portland cement, slag portland cement, portland fly-ash cement, compound portland cement, limestone portland cement, flexural strength and compressive strength inspection. When other cement adopts this standard, the applicability of this standard must be studied.

2 Normative References

The articles contained in the following documents have become this standard when they are quoted herein. For the dated documents so quoted, all the modifications or revisions made thereafter shall not be applicable to this Standard. For the undated documents so quoted, the latest editions shall be applicable to this Standard.
GB/T 6003-1985 Test sieve
JC/T 681-1997 Mixer for mixing mortars
JC/T 682-1997 Jolting table for compacting mortars specimen
JC/T 683-1997 40mm x 40mm Jig for cement compressive strength test machine
JC/T 723-1982(1996) Apparatus for physical test of cement-mortar vibration compaction equipment
JC/T 724-1982(1996) Apparatus for physical test of cement-electrically driven flexure testing device
JC/T 726-1997 Mould for cement mortars

3 Principal Features of Method

The method comprises the determination of the compressive, and optionally the flexural, strength of prismatic test specimens 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 and three parts by mass of standard sand with a water/cement ratio of 0.5. Standard sands from various sources and countries may be used provided that they have been shown to give cement strength results which do not differ significantly from those obtained using the ISO Reference sand (see Chapter 11).
The mortar is prepared by mechanical mixing and is compacted in a mould using standard jolting apparatus, or the jolting apparatus with 0.75mm amplitude and 2800~3000 t/m frequency can be used (see Chapter 11).