JC/T 2469-2018 in English
VALIDCementious materials-reducing admixture for concrete
- Issued on:2018-04-30
- Implemented on:2018-09-01
- File Format:PDF
- Delivery:Via email within 1~3 business days
$127.00
本标准规定了混凝土减胶剂的术语和定义、标记、要求、试验方法、检验规则、包装、贮存等。
本标准适用于水泥混凝土中掺用的减胶剂。
Introduction
Analysis of the core content of the standard
JC/T 2469-2018 for the first time clearly defines Cementious materials-reducing admixture for concrete: a chemical admixture that can reduce the amount of cementitious materials without affecting the slump and 28d compressive strength under the condition of unchanged water-cement ratio.
Comparison of key technical indicators
| Performance category | Benchmark requirements | Glue reducing agent index |
|---|---|---|
| Glue reduction rate | — | ≥5.0% |
| Water reduction rate | — | ≥5.0% |
| 28d compressive strength ratio | 100% | ≥90% |
| Chloride ion content | — | <0.1% |
Key points for implementation of the standard
Specification of test methods
The standard strictly stipulates the requirements for raw materials: cement must comply with GB 8076, the fineness modulus of sand is controlled at 2.6-2.9, and gravel is 5-20mm secondary mix. The amount of cement in the benchmark concrete mix is fixed at 330kg/m³, and the amount of adhesive material is adjusted according to the reduction rate of adhesive material in the tested concrete.
Engineering application case
A commercial concrete station uses a product with a 7% reduction rate, and the cementitious material of C30 concrete is reduced from 380kg to 353kg, and the 28d strength reaches 35.2MPa, which meets the strength retention rate required by the standard (≥90%), and saves about 15 yuan per cubic meter of concrete.
Background of Standard Evolution
This standard fills the gap in the standard field of concrete adhesive reducers in my country. It was led by the Building Materials Industry Technology Information Institute and jointly formulated by more than 20 units. For the first time, the formula for calculating the adhesive reduction rate was clarified: Ru=(C0-C1)/C0×100%, providing a unified evaluation basis for the industry.
Implementation Suggestions
- When selecting an adhesive reducer, it is necessary to verify the homogeneity control value (density, pH value, etc.) provided by the manufacturer.
- Before engineering application, a compatibility test should be carried out, focusing on the setting time difference (the standard allows ±90min fluctuation)
- In freeze-thaw areas, an additional test of 50 freeze-thaw cycle strength loss rate ratios (≤100%) is required.
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