What are the differences in sampling points for different concrete admixtures?

As a practitioner of concrete admixtures, if you don’t understand the key points of sampling, it is undoubtedly equivalent to talking on paper. The editor of Anhui Yulong New Materials Co., Ltd. will take you to understand what are the differences in the sampling points of different admixtures?

(1) Concrete admixtures

Concrete admixtures are divided into nine categories according to GB8076-1997: ordinary water-reducing agent, high-efficiency water-reducing agent, early-strength water-reducing agent, retarding water-reducing agent Retarder, high-efficiency water-reducing agent, air-entraining water-reducing agent, early strength agent, retarder and air-entraining agent

The manufacturer should number the products in batches according to the output and production equipment conditions, and the dosage should be less than 1 % (including 1%) of the same type of additives, each number is 100 tons, each number of admixtures with a content of less than 1% is 50 tons, less than 100 tons or 50 tons can also be counted as one batch, the same number The product must be mixed evenly

The sample amount of each batch shall not be less than 0.2 tons of cement and the required additional dosage

The samples obtained for each number should be fully mixed and divided into One of the two equal parts shall be tested according to the methods and items specified in the GB8076-1997 standard; the other part shall be sealed and kept for half a year in case of doubt, and submitted to the nationally designated inspection agency for re-inspection or arbitration. If the production and user units agree, the re-inspection shall be carried out. And arbitration can also take on-site sampling

(2) Concrete pumping agent

Every 50 tons of pumping agent is considered a batch, and if it is less than 50 tons, it is also regarded as a batch. The sampling amount of each batch is quite large. The required pumping dosage for 0.5 tons of cement

The samples obtained from each batch should be thoroughly mixed and divided into two equal parts. One part shall be tested according to JC473-92 concrete pumping agent; the other part shall be tested according to JC473-92 concrete pumping agent. A copy shall be sealed for half a year and submitted to the nationally designated inspection agency for re-inspection or arbitration in case of doubt

If the production and user units agree, average samples can also be taken on site, but this should be stipulated in the supply contract in advance.

(3) Concrete expansion agent

Every 60 tons is a batch, if it is less than 60 tons, it is also a batch.

Sampling should be representative and can be continuous For sampling, you can also take equal amounts of samples from more than 20 different parts. The total sampling volume of each batch should not be less than 10kg

The samples obtained from each batch should be fully mixed and divided into two equal parts. Concrete expansion agent (JC476-92) is tested; one copy is sealed and kept for three months, in case of doubt, submitted to the nationally designated inspection agency for re-inspection or arbitration

(4) Mortar concrete waterproofing agent

For an annual output of more than 500 tons, every 50 tons is a batch; for an annual output of less than 500 tons, every 30 tons is a batch. Products in the same batch must be uniform

Each batch The waterproofing dose required for a sampling volume of not less than 0.2 tons of cement

The samples obtained from each batch should be thoroughly mixed and evenly divided into two equal parts and one should be processed according to the mortar concrete waterproofing agent (JC474-92) standard. Test; the other copy shall be sealed and kept for one year, in case of doubt, submitted to the nationally designated inspection agency for re-inspection or arbitration

(5) Concrete antifreeze

The same type of antifreeze , every 50 tons is a batch, less than 50 tons can also be used as a batch. The amount of antifreeze required for each batch of cement should be no less than 0.15 tons (based on the maximum dosage)

Obtained for each batch The sample should be thoroughly mixed and divided into two equal parts. One part shall be tested according to the concrete antifreeze (JC475-92); the other part shall be sealed and kept for half a year, in case of doubt, it shall be submitted to the nationally designated inspection agency for re-inspection or arbitration.

(6) Concrete accelerating setting agent

Every 20 tons is a batch, less than 20 tons can also be used as a batch

Each batch should be from 16 different Point sampling, take 250g from each point, and take a total of 400g. Mix the sample thoroughly. The samples obtained in each batch should be fully mixed, divided into two equal parts, and one part is tested according to the shotcrete accelerating setting agent (JC477-92). ; The other copy shall be kept sealed for half a year and submitted to the state-designated inspection agency for re-inspection or arbitration in case of doubt.

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