Who set the sampling standard for cement?
Sampling test method for common building materials
I. Cement
1, test standard:
(1) Strength Test Method for Cement Mortar (ISO Method) (GB/T17671-1999)
(2) Test Method for Water Consumption, Setting Time and Stability of Standard Consistency of Cement (GB/T 1346-200 1).
(3) Test Method for Cement Fineness (GB 175- 1992)
(4) Portland cement, pozzolanic portland cement and sludge (GB 1344- 1992).
(5) Portland cement such as slag portland cement, pozzolanic portland cement and sludge (GB 1344- 1992)
2, numbering and sampling
Cement shall be numbered and sampled according to the same variety and label before leaving the factory. Bagged cement and bulk cement shall be sampled by numbers respectively, and each number shall be a sampling unit. The number of cement plant shall be specified according to the annual production capacity of cement plant.
3, sampling and sample delivery regulations:
(1), first of all, it is necessary to know whether the cement manufacturer purchased has the product production license and the construction engineering material license issued by Shanghai Construction Committee.
(2) The entrusted inspection samples of cement must take each factory cement number not exceeding 400T as a sampling unit, and there shall be no mixed sampling of more than two factory numbers.
(3) Cement samples must be collected in different parts of the same number, and the sampling point should be at least 20 points. After mixing evenly, package in a moisture-proof container with a weight of not less than 12Kg.
(4), the entrusting unit must fill in the inspection list item by item, such as cement manufacturer's name, trademark, variety, label, factory number or date, project name, physical inspection items (stability, strength, fineness, consistency, setting time, etc. ).
(5) If the cement factory date exceeds three months, it shall be rechecked before use, and the samples shall be kept for three months.
Second, sand and stones.
1, test standard:
(1) code for concrete test of waterway engineering (JT270- 1998),
(2) Code for Concrete Construction of Waterway Engineering (JTJ268- 1996).
2, the acceptance of sand and gravel
According to the same origin, the same specifications in batches, large-scale tool transportation, with 600t as an acceptance batch.
3, sampling regulations:
(1), when sampling on the material pile, the sampling parts should be evenly distributed. Before sampling, the surface layer of the sampling site should be removed, and then about 8 samples should be taken from each part of the sand to form a group of samples, and about 15 samples should be taken from each part of the stone (samples should be taken from five different parts evenly distributed at the top, middle and bottom of the pile) to form a group of samples.
(2) When sampling from automobiles and cargo ships, eight approximately equal parts of sand and 16 parts of stones should be taken from different positions and depths to form a group of samples.
(3), if the inspection is unqualified, should be re-sampling.
(4) The inspection quantity of stones is the maximum particle size of stones ×2kg. If the maximum particle size is 3 1.5mm, the sampling amount is 3 1.5mm, and the sampling amount is 3 1.5×3=63kg.
(5) Each group of samples shall be properly packaged and attached with a sample card, indicating the number, name, sampling time, origin, specifications, sample quantity, inspection items and sampling method.
4. Test items:
(1). For sand, each acceptance batch should at least check the particle size distribution, sand content and mud content. According to the needs of the project, additional inspection items can be added, such as apparent density and bulk density. The quantity of sand for inspection shall be at least 25 kg.
(2) For stone materials, each acceptance batch shall at least check the particle gradation, silt content and clod content. (If the test meets the requirements for more than three consecutive times, it can be done once a month, and then it can be done once a quarter for three consecutive times). According to the needs of the project, testing items can be added.
Third, the steel substrate
(1) mechanical properties
1, test methods and standards:
(1), tensile test method for metals (GB228- 1987)
(2) Bending test method for metal materials (GB/T232- 1999)
(3) Hot rolled ribbed bar for reinforced concrete (GB 1499- 1998)
(4) Tensile Test Method of Metallic Materials at Room Temperature (GB/T228-2002)
(5) Low carbon steel hot rolled round steel (GB/T70 1- 1997)
(6) Code for Concrete Construction of Waterway Engineering (JTJ268- 1996)
2. Sampling rules
(1), steel bars shall be accepted in batches, each batch shall not exceed 60t, and each batch shall be composed of steel bars of the same brand, the same heat number, the same specification and the same delivery status.
(2) Cold-drawn steel bars shall be accepted in batches, and each batch shall be composed of cold-drawn steel bars of the same grade and diameter with the weight not exceeding 20t.
3. Sampling quantity
The number of reinforcement samples varies according to its supply form.
(1), straight steel bars and cold-drawn steel bars shall be subjected to two tensile tests and two bending tests for each batch;
(2) For wire reinforcement, each batch of plates shall be subjected to 1 tensile test and 2 bending tests.
4. Sampling method
The samples of tensile and bending tests can be cut from any two steel bars in each batch of materials, and the 50cm head is removed, and each steel bar is stretched and bent.
Length of reinforcement daily habit specimen: unit (mm)
Sample diameter Stretch sample length Bend sample length Bend sample length repeatedly.
6.5~20 300~400 250 150~250
22~32 350~450 300
5. Fill in the power of attorney: the model, diameter, manufacturer, factory number or furnace number, representative tonnage, project name, full name of user, sample sender, sample delivery date, full name of witness, witness and witness ID number must be filled in.
(2), steel chemical analysis:
1, test methods and standards:
(1), hot rolled round steel for reinforced concrete (GB13013-1991)
(2) Hot rolled ribbed bar for reinforced concrete (GB 1499- 1998)
(3) Waste Heat Reinforcement for Reinforced Concrete (GB13014-1991)
(4) Carbon structural steel (GB/700- 1988)
(5) Low carbon steel hot rolled round steel (GB/T70 1- 1997)
2, each furnace tank number of steel should be sampled for chemical analysis; When brittle fracture, poor welding performance or obvious abnormal mechanical properties of steel bars are found during processing, chemical composition inspection or other special inspections should be carried out. The supplier shall provide chemical analysis guarantee.
3, the sample must be taken from the representative parts of steel, sample fragments can be drilled, planed, should be crushed and mixed evenly, and remove the surface scale and dirt.
Four, steel weldments:
1, test specifications and standards:
(1), Code for Concrete Construction of Waterway Engineering (JT268- 1996)
(2) Standard for Test Methods of Welded Joints of Reinforcement (JGJ/T27-200 1)
2, flash butt welding:
① Six test pieces shall be cut from each batch of finished products, three for tensile test and three for bending test;
(2), in the same class, completed by the same welder of the same level and diameter of 300 steel welding head should be regarded as a batch. When the number of welded joints at the same level is small, it can be calculated cumulatively within one week; When the cumulative number of joints is still less than 300, it shall be counted as a batch;
(3) Before flash butt welding, if the steel grade and diameter are changed or the welder is changed, two samples shall be made for cold bending test, and batch welding can be carried out according to the corresponding parameters only after passing the test. ;
④ Sampling scale
Tension steel bar: 40 ~ 50 cm
Bending steel bar: (D+2.5D)+ 150mm (applicable steel bar diameter is 10 ~ 25mm) Note ≤2.5mm D = 4dd- steel bar diameter.
(5), joint can not have transverse crack; The bending angle of the joint shall not be greater than 4 degrees; Axis deviation of rebar at the joint shall not be greater than 0. 1 times rebar diameter, and shall not be greater than 2mm at the same time.
3. Resistance welding
(1), all welded products with the same steel grade, diameter and size are the same type of products, and every 200 pieces are a batch; (2) Shear test shall be conducted for spot welding of hot rolled steel bars, with 3 specimens; In addition to the shear test, the cold-drawn low-carbon steel wire solder joint should also be subjected to the tensile test of the smaller steel wire, with 3 specimens.
4. Arc welding
(1), under the condition of factory welding, 300 joints of the same type (same steel grade, same joint type) are taken as a batch; Less than 300, still as a batch.
② Cut three joints from each batch of finished products for tensile test, and the sampling size is 40 ~ 60 cm.
(3) Before arc welding, or when changing the steel grade, diameter, covered electrode model and welder, two tensile tests should be conducted. When the test result is greater than or equal to the tensile strength of this kind of steel bar, formal trial welding is allowed.
(4) The weld length of arc welding is 10d on one side and 5d (d-rebar diameter) on both sides.
5, welding power of attorney to fill in:
The model, diameter, welding form, welder's name, welder's certificate number, project name, user's full name, sample sender, sample delivery date, number of representative joints, full name of witness unit, witness and witness certificate number must be filled in.
Five, concrete specimen:
1, test specifications and standards:
(1) Code for Concrete Construction of Waterway Engineering (JTJ268- 1996)
(2) Code for Concrete Test of Waterway Engineering (JTJ270- 1998)
2. Sampling frequency of concrete samples:
(1), mixing concrete on site:
Concrete samples shall be randomly selected at the concrete pouring site, and the sampling frequency shall meet the following requirements:
(1), continuous pouring of more than 40m3 of concrete, every 100 m3 take a group, less than 100 m3 should also take a group.
(2), continuous casting is less than or equal to 40 m3, every 20 ~ 40 m3 take a group; When it is less than 20 m3, take one group per shift.
(3), when the mixture ratio changes, each mixture ratio shall be retained specimen.
(2), commercial concrete
(1), the concrete samples used for delivery inspection shall be sampled at the delivery place, and the concrete with the same mixture ratio shall be sampled at least once every 100m3. When the concrete with the same mixture ratio mixed by a working shift is less than 100 m3, the samples shall be sampled at least once. When a large amount of concrete with the same mixture ratio continuously supplied by a sub-project is greater than100,
(2), used for the factory inspection of concrete samples shall not be less than once, each class of the same mixture ratio of concrete is less than 100 plate, sampling shall not be less than once.
(3) For the quality of ready-mixed concrete mixture, each vehicle shall be visually inspected, and the concrete slump test shall be sampled. The sampling test of concrete with the same mixture ratio shall not be less than once every 100m3, and when the concrete with the same mixture ratio in a working class is less than 100 m3, it shall not be less than 1 time.
3. Witness the delivery of concrete samples:
The concrete specimen must be delivered by the sample delivery member of the construction unit in conjunction with the construction unit (or the entrusted supervision unit). When entering the laboratory, you should carefully fill in all the contents required by the "entrustment form", such as project name, use position, design strength grade, tamping date, mixture ratio, slump and so on.
Six, cement mortar
1, test specifications and standards:
(1), Code for Concrete Test of Waterway Engineering (JTJ270- 1998)
(2) Code for Concrete Construction of Waterway Engineering (JTJ268- 1996)
2. Sampling method
Three test pieces shall be made for each batch of cement pads, with the size of 70.7×70.7×70.7 and three dies.
3. Entrust to fill in:
Full name of entrusting unit, project name, project location, mixture ratio, molding date, cement dosage per party, cement variety, sample sender, sample delivery date, full name of witness unit, witness, witness number and compressive strength.
Seven, concrete admixture:
1, admixture test methods and standards:
(1), concrete admixture (GB8076- 1997)
(2) Test Method for Uniformity of Concrete Admixtures (GB/T8077-2000)
2, admixture types:
Ordinary water reducer, high-efficiency water reducer, retarded high-efficiency water reducer, early strength water reducer, retarded water reducer, air-entraining water reducer, early strength agent, retarder and air-entraining agent.
3. Number of samples:
The sampling quantity of each batch shall not be less than 0.2T of the additional dosage required for cement. The samples of each number shall be fully mixed and divided into two equal parts, one of which shall be tested according to the methods and items specified in GB8076- 1997 standard, and the other shall be sealed and kept for half a year. The representative number of each sample shall not exceed 10t. And provide factory warranty.
4. Test items:
(1) liquid: solid content, density, PH value, water reduction rate (not every time).
(2) Solids: water content, fineness and water reducing rate of mortar.
Eight, concrete pumping agent:
1, test specifications and standards:
Concrete pumping agent (JC473-200 1)
2. Sampling quantity:
The sampling quantity of each batch is not less than 0.5T of pumping agent required for cement; Fully mix the samples obtained from each number and divide them into two equal parts, one of which is tested according to JC473-200 1 standard, and the other is sealed for half a year. The representative number of each sample shall not exceed 10t. And provide factory warranty.
3. Test items:
Liquid: the solid content, density and fluidity of cement slurry (it is not necessary to do it every time)
Nine, fly ash:
1, test specifications and standards:
(1), Technical Specification for Fly Ash Concrete in Port Engineering (JTJ/T273- 1997),
(2) Code for Test of Concrete in Waterway Engineering (JTJ270- 1998),
(3) Chemical Analysis Methods of Cement (GB/T 176- 1996).
2. Fly ash sampling should be based on a batch of 200 tons of fly ash of the same grade continuously supplied by the same ash source; Less than 200 tons, counted as a batch.
3. For bulk ash sampling, 15 samples should be taken from different parts of each batch, and each sample should be no less than 1kg and mixed evenly. According to the quartering method, the sample is twice the test dose. The sampling quantity is 6kg.
4. Test items:
(1), general test items: fineness and ignition vector;
(2) A complete set of testing items: fineness, combustion vector, water content, water demand ratio and sulfur trioxide. The fineness and loss on ignition of each batch of fly ash should be determined. When the ash source changes, the ratio of SO3 to water demand should be determined, and the SO3 content of the same ash source should be determined once every quarter.
Ten, granulated blast furnace slag powder:
1, test procedures and standards
(1), technical specification for application of granulated blast furnace slag powder in cement concrete (DG/TJ08- 1999)
(2) Granulated Blast Furnace Slag Powder for Cement and Concrete (GB/T 18046-2000).
2. Sampling method:
Take equivalent samples from more than 20 different parts, with a total amount of at least 20 kg. After the samples are mixed evenly, they are reduced to twice the amount needed for the test by quartering. Sampling quantity: 6kg. The number of delegates shall not be more than 200 tons per batch.
3. Test items:
Total activity, liquidity.
XI。 Sand for filling:
1, test specifications and standards
(1), Code for Concrete Construction of Waterway Engineering (JTJ268- 1996)
(2) Code for Concrete Test of Waterway Engineering (JTJ270- 1998)
2. From the same sand sampling point, every 1000m3 is a sample, which is reduced to a sample by quartering. The sampling quantity is 8 kg.
3, quality evaluation standard:
(1), when the sand content greater than 0.075mm is greater than 9 1% of the total mass, it can be judged that the quality of the sand sample meets the requirements, and the clay content of 0.05 mm does not need to be tested. ..
(2) When the content of sand with particle size greater than 0.075mm is greater than 85 ~ 90% of the total mass, the content of sand with particle size greater than 0.05mm is increased. When the content of sand with particle size greater than 0.05 is greater than 90% of the total mass, the quality of this batch of sand samples meets the requirements.
4. Test items:
Particle gradation and silt content
Twelve, geotextile:
1, test specifications and standards:
(1) and geotextile sampling and test preparation (GB/T 13760- 1992).
(2) Technical Specification for Application of Geotextiles in Waterway Engineering (JTJ/T239- 1998)
2. Determine the number of samples:
380g/m2 composite cloth, 230g/piece
M2 woven fabric shall be randomly sampled at 10000m2, reinforcing belt and polypropylene rope shall be randomly sampled at 20000m, and each batch shall be sampled at least once.
3. Select a package:
After the number of selected packages is determined, the packaging should be selected in the product workshop, warehouse or delivery site, and it should be randomly selected without damage, and the black plastic packaging should be complete.
4. Cut the sample:
(1) packaging, cut a full-width section of the selected packaging as a sample, and the sample length should meet the requirements of all inspection items for sample size, so as to ensure that all inspection samples are cut in the same sample. Generally speaking, the suitable geotextile is 6m2, 7m reinforced belt, 15m polypropylene rope and 3m seam length (40cm width).
(2) Samples should avoid visible defects such as stains, creases and holes in the first two layers of the package due to non-production reasons.
5. Mark the sample:
Indicate the longitudinal direction of the package (that is, the longitudinal direction or radial direction of the product), supplier or manufacturer, product name, number of rolls and sampling date with arrow marks.
Step 6 save the sample
After marking, roll it up, don't fold it, and send it to the testing department.
7. Test items:
(1), 380g/m2 composite fabric, 230g/m2 woven fabric:
Unit mass, thickness, tensile strength, elongation, trapezoidal tear strength, bursting strength, puncture strength, cone penetration diameter, aperture and vertical permeability coefficient.
(2), steel belt, polypropylene rope:
Unit weight, tensile load, elongation.
Explanation:
In order to ensure the quality of materials entering the site, according to Article 6. 1.5 of Code for Supervision of Waterway Engineering Construction (JTJ 2 16-2000), the supervisor shall conduct parallel tests on materials and concrete specimens detected by the construction unit, and the parallel tests shall be 10% of the quantity detected by the construction unit. Planning and randomization should be combined. Parallel testing projects should be centralized and comprehensive. Both proportional sampling and encrypted sampling can be used to solve the problems found in the project. In short, they should be representative and fully supervised. Parallel test work cannot be replaced by the laboratory of the construction unit, nor can it be carried out in any test department at will. Parallel test work can not affect the construction progress, nor can it be used before trial. If the re-inspection result of the construction unit is inconsistent with the parallel inspection conclusion of the supervisor, the parallel inspection result of the supervisor shall prevail, and the unqualified products shall be returned, and the return account shall be kept.