GB 25779-2010Loadbearing concrete perforated bricks (English PDF)

4.1 Specifications

Concrete brick hexahedral shape is a right angle, the usual brick size specifications shown in Table 1.

Table 1 Size millimeters

length Width Height

360,290,240,190,140 240,190,115,90 115,90 Other sizes may be negotiated through consultation. A thin mortar joint of masonry block type, relevant dimensions can be adjusted accordingly.

4.2 Rating

Press the compressive strength is divided into MU15, MU20, MU25 three levels.

4.3 Mark

Labeled products in the following order. code, size, strength grade, standard number.

Example. Size of 240mm × 115mm × 90mm, MU15 strength grade of concrete brick, mark it as.

5.1 Cement

Shall comply with the provisions of GB 175.

5.2 Aggregate

5.2.1 Fine aggregate

Shall comply with GB/T 14684 of.

5.2.2 Coarse aggregate

Gravel, pebbles shall comply with GB/T 14685; the weight of the slag should comply YBJ20584. Coarse aggregate maximum particle size should not be Greater than 9.5mm.

5.2.3 Lightweight aggregate

Shall comply with the provisions of GB/T 17431.1 of.

5.3 Fly

Shall comply with the provisions of GB/T 1596's.

5.4 Blast furnace slag

Shall comply with GB/T 18046 of.

5.5 Admixtures

Shall comply with the provisions of GB 8076.

5.6 Water

Shall comply with the provisions of JGJ63.

5.7 Other material

Shall comply with the relevant standards, the relevant inspection should be done before the application of non-standard materials, meet the requirements before use.

6.1 Appearance quality

Appearance quality should be consistent with the provisions of Table 2.

Table 2 Appearance quality millimeters

Name of Project Specifications Bending <=1 Missing edge off angle Number (number) <=2 A maximum of three directions projection size <=15 Cumulative crack extending projection size <=20

6.2 Size bias

Size deviation shall be as specified in Table 3.

Table 3 millimeters size deviation

Name of Project Specifications Length 2, -1 Width 2, -1 Height ± 2 Porosity of 6.3 6.3.1 porosity of not less than 25%, not greater than 35%.

6.3.2 concrete brick opening direction, on the wall to be built same direction after the pressures and brick.

6.3.3 any hole concrete brick, tile maximum value of the longitudinal direction should not exceed 1/6 of the length of the brick; brick width direction the maximum value should be less than 4/15 the width of the brick.

6.3.4 slurry laying surface concrete brick or semi-blind holes should be a blind hole.

6.4 The minimum outer wall thickness and minimum rib the minimum outer wall thickness should be not less than 18mm, the minimum rib thickness of not less than 15mm.

6.5 Intensity level

Compressive strength shall be as specified in Table 4.

Table 4 compression strength in megapascals

power level

Compressive strength the average value is not smaller than the minimum value not less than the monolith MU15 MU20 MU25 15.0 20.0 25.0 12.0 16.0 20.0

6.6 The maximum water absorption the maximum water absorption should not exceed 12%.

6.7 Linear drying shrinkage and relative moisture content

Linear drying shrinkage and relative moisture content shall be as specified in Table 5.

Table 5% relative moisture content

Linear drying shrinkage Relative water content Moderate drying wet <=0.045 <=40 <=35 <=30 Note. Use the areas humidity conditions.

--- means a wet annual average relative humidity greater than 75% of the area;

Medium --- refers to the annual average of 50% to 75% relative humidity areas;

--- means a dried average area of less than 50% relative humidity.

6.8 Frost resistance

Frost resistance shall be in accordance with Table 6.

Table 6% frost resistance

Freezing conditions index monolithic mass loss rate of loss of compressive strength monolithic Subtropical region D15 Hot summer and cold winter area D25 Cold regions D35 Cold regions D50 <=5 <=25

6.9 Carbonation coefficient

Carbonization coefficient of not less than 0.85.

Softening coefficient 6.10 Softening coefficient of not less than 0.85.

6.11 Radioactive

Radioactive shall comply with the provisions of GB 6566.

7.1 Appearance quality

Appearance Quality test method according to GB/T 2542.

7.2 Size bias

Size deviation test method according to GB/T 2542.

Porosity of 7.3

7.3.1 porosity of test methods according to GB/T 4111 Test Method hollowness.

7.3.2 sitting surface concrete brick slurry, measured with a caliper or ruler aperture or hole geometry, calculating the maximum hole size, using Full comparison value, to the nearest 0.1mm.

7.4 The minimum outer wall thickness and minimum rib the minimum outer wall thickness of the ribs and the minimum test method according to GB/T 4111.

7.5 Compressive strength

Test method for compressive according to annex A.

7.6 The maximum water absorption the maximum water absorption test method according to GB/T 4111.

7.7 Linear drying shrinkage and relative moisture content

Linear drying shrinkage and relative moisture content test method GB/T 4111 for which the linear drying shrinkage test gauge length 150mm.

7.8 Frost resistance

Frost resistance test methods according to GB/T 4111 for which the compressive strength test method according to Appendix A.

7.9 Carbonation coefficient

Test Method carbonation coefficient according to annex B.

Softening coefficient 7.10 Test methods for softening coefficient according to annex C.

7.11 Radioactive

Radioactive carried out in GB 6566.

8.1 Inspection Classification

Product testing into the factory inspection and type test.

8.1.1 Factory inspection

Test items. appearance quality, dimensional deviation, the minimum and the minimum rib thickness of the outer wall, the intensity level, the maximum water absorption and relative water content.

8.1.2 Type inspection

Test items are. All project technical requirements of Chapter 6. Any of the following circumstances, should be type tested.

Pattern evaluation trial a) new products;

b) for normal production, raw materials and production process of any one of the ratio change occurs;

c) Normal production, every six months (every radioactivity once a year);

d) production line shutdown recovery more than three months of production;

E) When the last delivery inspection and test patterns are quite different;

f) the national quality supervision agencies to proceed with a comprehensive inspection.

8.2 Batch rules

With the same batch of raw material, the same production technology, the same level of intensity and the same age of the 100,000 concrete brick as a group, not Foot 100 000 also by the number of dollars.

8.3 Sampling rules

8.3.1 each batch of 50 randomly concrete brick made appearance quality and dimensional deviation test.

8.3.2 dimensional deviation from the appearance and quality inspection of concrete brick is extracted as the number of other items for inspection, the number of samples

Table 7.

TABLE 7 Sample Number of Units blocks

Test items

Number of samples

(H/B) >=0.6 (H/B) Appendix A (Normative) Concrete brick compressive strength test method A.1 equipment A.1.1 Testing Machine it shows the relative value of the material testing machine error should not exceed ± 1%, which can be expected to range selection failure load of the specimen falls full scale 20% to 80%. The testing machine, one end of the lower platen should be twisted ball bearings, and freely rotatable.

A.1.2 auxiliary platen when the upper platen or the lower platen of the testing machine can not completely cover the surface of the support bearing surface of the test piece, the test machine should be placed between the platen and the specimen as a set of auxiliary pressing plate.

Auxiliary platen length and width should be greater than the length of each test piece, a width of 6mm, a thickness of not less than 20mm. Thermally assisted platen Surface hardness after not less than HRC40. Flatness tolerance of 0.12mm.

A.1.3 internet specimen prepared Preparation of test piece should be flat horizontal platform, flatness within its scope the longitudinal direction should be less than 0.1mm, metal or other material can be used Make, planar dimensions should not be less than 440mm × 240mm.

A.1.4 glass plate

Glass plate thickness not less than 6mm, the planar size and requirements of the test pieces prepared in the same platform.

A.1.5 level

Level specifications for 250mm ~ 400mm.

A.1.6 right angle ruler One end of a right angle ruler shall be not less than the length of 120mm, the indexing is 1mm.

A.1.7 steel ruler

Specifications for steel ruler 400mm, indexing is 1mm.

A.2 specimen screed material and a binder 42.5 mortar prepared using ordinary portland cement and sand, 1.3 mass ratio, the value of water amount of water specified in GB/T 1346 Mud normal consistency.

To advance compressive strength tests, 42.5 should be used Portland cement or rapid hardening high strength gypsum powder. Lower strength should not be used Gypsum powder model, building plaster powder.

Arbitration test should be used 42.5 ordinary portland cement.

A.2.1 rapid hardening Portland cement the method according to GB/T 17671 a predetermined molding, curing, and testing the compressive strength of cement mortar test block. Cement mortar test block age 24h the compressive strength of not less than 19.0MPa.

A.2.2 high-strength gypsum powder A.2.2.1 Test for compressive strength gypsum powder predetermined GB/T 17669.3, the wet strength of not less than 2h instar 24.0MPa.

A.2.2.2 laboratory purchased high-strength gypsum powder, should be used within three months; if beyond 3 months of shelf life, should be re-compressive strength Inspection, after passing to continue to use.

A.2.2.3 addition retarder, gypsum powder should not adding any other fillers and additives. High-strength gypsum powder supplier must provide Retarder dosage and Mix requirements.

A.3 Specimen

A.3.1 number of specimens Compressive strength of concrete brick number of five specimens.

A.3.2 sample handling A.3.2.1 side porous brick concrete sample should be regular flat, irregular or if protruding ribs, need to be cut, so as to Ensure the smooth side of the sample; processing sitting surface and pulp slurry paved surface, making a plane parallel to each other; holes all around the mixed sample Concrete walls or floors should be completely closed, the compressive strength of the test piece should be regarded as monolithic concrete brick compressive strength.

A.3.2.2 After the sample at a temperature of at least (23 ± 5) °C, relative humidity less than 80% for down to a constant weight, before proceeding specimens produced.

When scattered on a laboratory sample, the laminate can be stacked, holes should be parallel to the ground, the interval between samples is not less than 15mm. For advance Compressive strength test, you can use electric fans to speed up the indoor air flow rate. When the mass loss after 2h of not more than the previous sample mass 0.2%, and, when there is moisture or wet phenomena see sample surface was visually observed, the sample may be considered to have a constant weight. Do not allow the use of drying Box dried sample.

A.3.3 size measurement Steel ruler to measure the size of each sample were measured width of the specimen (B) and length (L) in an intermediate position on both sides of the sample, averaged, Accurate to 1mm; sample height (H) takes two values should be measured at the middle of two long side (L), are averaged to the nearest 1mm.

A.3.4 Preparation of test piece Calculating concrete brick in the actual use state of the pressure height (H) and the minimum horizontal dimension (B) ratio, i.e., the aspect ratio (H/B).

Preparation A.3.4.1 H/B>=0.6 specimens Using the slurry method take into test pieces, directly after the treatment as the compressive strength of the specimen.

A.3.4.1.1 first sample platform on a preparative thin coat of oil or a layer of wet paper, the stirred material is uniformly leveling the paving Preparation of samples on the platform, the length and width of the leveling material layer should be slightly larger length and width of the sample.

A.3.4.1.2 selected concrete brick paved surface as a slurry pressure-bearing surface, the bearing surface of the sample material is pressed into the leveling layer, with a right angle on foot to Regulation sample vertical. After sitting surface pressure slurry to at least 90 ° to the two adjacent side vertical relationship. Leveling the material thickness should be less than 3mm.

When the bearing surfaces A.3.4.1.3 final setting leveling material, the other surface of the slurry for sitting by the above method, the sample is pressed into the leveling material layer, for an with the regulation of the surface level to level.

A.3.4.1.4 to shorten the time, immediately screeds layer side upward pressure receiving surface plated after treatment, the oil pressure on the previously coated glass Tablet, bead edge screeds layer was observed, all air bubbles removed, and the level adjusted horizontal ruler until a uniform plane leveling mortar layer thickness <=3mm.

Preparation of test piece A.3.4.2 H/B Appendix B (Normative) Test Method for Coefficient carbonation concrete brick B.1 equipment B.1.1 compressive strength test equipment with A.1.

B.1.2 carbonization chamber Specimen discharge volume at least more than one set.

Inside the environmental conditions. volume of carbon dioxide at a concentration of (20 ± 3)%, relative humidity (70 ± 5)%, a temperature of (20 ± 5) °C.

B.2 chemical reagents Mass concentration of 1% phenolphthalein ethanol solution with a concentration of 70 mass% ethanol formulation.

B.3 sample

The number of samples B.3.1 Aspect ratio (H/B) Number of samples >=0.6 concrete brick 12 is two; compressive strength of a set of five comparative sample. another Group 7 carbide test sample, wherein the test 2 for carbonation.

Aspect ratio (H/B)