GB 15230-1994 Concrete supporting components for farm houses

This standard specifies the classification, quality grade, technical requirements, test methods and inspection rules of concrete supporting components for farmhouses. This standard applies to concrete doors, window lintels, balcony cantilever beams and stair treads used in housing, offices, primary and secondary school classrooms, etc. built in rural areas and towns. GB 15230-1994 Concrete supporting components for farmhouses GB15230-1994 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Complete sets of rural-housing concrete elements1Subject content and scope of application
GB15230-94
This standard specifies the classification, quality grade, technical requirements, test methods and inspection rules of rural-housing concrete elements. This standard is applicable to concrete doors and window lintels (hereinafter referred to as lintels), balcony arm beams (hereinafter referred to as balcony beams) and stair treads (hereinafter referred to as treads) used in houses, offices, primary and secondary school classrooms, etc. built in rural areas and towns. 2 Reference standards
G13175 Portland cement, ordinary Portland cement GB1344 Slag Portland cement, pozzolanic Portland cement and fly ash Portland cement GB1499
Hot-rolled ribbed steel bars for reinforced concrete
GB8076 Concrete: soil admixtures
Sand for construction
GB/T 14684
G13/T14685 Pebbles and crushed stones for construction
GB"107 Concrete strength test and evaluation standard
Construction and acceptance specification for reinforced concrete engineering GB1 201
ZB3Q14002.2 Testing method for compressive strength of concrete components in rural housesZBQ14002.3 Testing method for appearance quality and geometric dimensions of concrete components in rural housesZBQ14002.4 Testing method for mechanical properties of concrete components in rural housesJGJI19 Design and construction code for small and medium-sized components of cold-drawn low-carbon steel wire prestressed concreteJGJ63 Quality standard for water used in mixing concrete
3 Classification
3.1 Varieties
3.1.1 Lintels
Lintels are divided into prestressed concrete lintels (hereinafter referred to as prestressed lintels) and reinforced concrete lintels (hereinafter referred to as concrete lintels). 3.1.2 Balcony beams
Balcony beams are reinforced concrete balcony beams (hereinafter referred to as balcony beams). 3.1.3 Treads
Treads are divided into two categories: prestressed concrete treads (hereinafter referred to as prestressed treads) and reinforced concrete treads (hereinafter referred to as concrete treads).
3.2 Levels
Balcony beams and treads are divided into two levels according to different standard values ​​of uniformly distributed live loads (see Table 1), and lintels are divided into 6 levels according to the deadweight of the wall borne by their upper parts and the uniformly distributed loads transmitted by the slab surface (see Table 2). Approved by the State Administration of Technical Supervision on September 24, 1994 232
Implemented on June 1, 1995
Component types
Yangdi beam
Tread||Combined load
GB15230-94
Table 1 Balcony beam and tread load levels
Standard values ​​of uniform live loads of different levels
Table 2 Lintel load levels
Note: G in the table refers to the deadweight of the wall at 1/3 of the clear span height above the lintel, and 5-25kN/m refers to the uniformly distributed load transmitted by the board surface. 3.3 Specifications
3.3.1 Appearance
3.3.1.1 Lintel: See Figure 1.
3.3.1.2 Balcony beam: See Figure 2.
3.3.1.3 Treads: See Figures 3 and 4.
Figure 1 Lintel
a) Rectangular section b) Two rectangular combined sections c) Two L-shaped combined sections d) Rectangular section with holes kN/m
3.3.2 Sectional dimensions and length
GB15230—94
2 Balcony beam
Figure 3 Flat treads
Figure 4 L-shaped treads
3.3.2.1 The cross-sectional dimensions and length of the lintel shall comply with the provisions of Table 3. 3.3.2.2 The cross-sectional dimensions and length of the balcony beam shall comply with the provisions of Table 4. 3.3.2.3 The cross-sectional dimensions and length of the treads shall comply with the provisions of Table 5. 251
180×50
240×50
370×50
180×60
240×60
370×60
180× 100
240×100
370X100
180×120
240×120
370×120
180×180||tt ||240X180
370×180
180X240
240×240
370×240
180×300
240×300
370×300
2 rectangles
2 L-shapes
2 rectangles
2 1-shapes
2 rectangles
2 1-shapes
GB 15230—94
Table 3 Cross-sectional dimensions and length of lintels
Load levels
1100, 1200, 1300, 1400
1100, 1200, 1300, 1400, 1500, 1600, 17001100, 1200
1200.1300.1400, 1500, 1700, 19001200, 1300, 1400, 1500, 17 0011001200, 1300, 1400
1400, 1500, 1700, 1900, 2000, 23001300, 1400, 1500, 1700, 1900, 200 01100,1200.1300,1400.1500,1700.19001100,1200,1300,1400.1500,17001100,1200,1300,1400, 15002000, 2300, 2600, 2900, 3200, 35001900, 2000, 2300, 2600, 29001700, 1900, 2000, 2300, 260017 00,1900.2000
2600, 2900, 3200, 3500
2300, 2600.2900, 3200
2300,2600.2900| |tt||2300.2600
2900,3200.3500
240×100
240X150
240×180
Draining holes 50~60
240×100
240×160
（q102)
2 L-shaped
Prestressed rectangle
Note: Other specifications are determined by the design department. Type
Sectional size
bXh/hi
240(220)X
240/120(150)
240(220)X
300/150
GB 15230—94
Continued Table 3
Load level
1100, 1200, 1300, 1400, 1500, 17001100, 1200, 1300, 1400
1500, 1700, 1900, 2000, 2100, 23001500.1700
1700, 1900, 2000
1100, 1200, 1300, 1400.1500, 17001500.1700
1500, 1700, 1900, 2000, 2100, 23001500, 1700, 1900
1 Balcony beam section size and length
2100, 2200, 23 00, 2400, 2500, 2600, 2700, 2800, 2900
2900, 3000, 3100.3200, 3300, 34003 100, 3200, 3300, 3400, 35002200, 2300, 2400, 2500, 2600, 2700, 2800, 2900.3000.3 100
2900, 3000.3100, 3200, 3300, 34003100.3200,3300, 3400, 3500
3100,3200.3300.3400
3200, 3300, 3400, 3500, 36003100, 3200, 3300, 3400.3500
3200, 3300, 3400, 3500, 3600mm
Balcony width
(span size)
3000~5000
3000~4700
3000～4000
3000~5000
3000~40 00
3000~~3600
4000~5000
4200~5000
3800~5000||t t||Section ruler
bXh/ht
240(220)X
240/120(150)
240(220) X
300/150
GB 15230--94
Continued Table 4
2400, 2500, 2600, 2700, 2800, 2900, 30002800, 2900, 3000, 3100
2500, 2600, 270 0, 2800, 2900.3000, 31002500, 2600, 2700, 2800, 2900, 3000, 31002800.2900.3000.3100,3200
3200, 3300, 3 400、3500、3600、37003400、3500、3600、3700、3800、39002500、2600、2700、2800、2900、3000、3100、3200
2900、3000.3100、3200
3300.3400、3500.3600
3700、3800、3900、4000
Note: (1) The 220 in brackets is based on the cross-sectional width of non-standard bricks. (2) Other specifications need to be determined by the design department. Tread section size and length
Prestressed 1 plate
250350
240~320
240~320
Note: Other specifications need to be determined by the design department. Surface
40, 50
150~200
150~200
3.4 ​​Grade
Lintel, balcony beam and tread are divided into first-class products and qualified products according to geometric size and appearance quality. 3.5 Code
3.5.1 Lintel
3.5.1.1 The code for prestressed lintel is as follows; mm
Balcony width
(span size)
3000～4000
3000~3400
4200~5000
3300～5000
30 00~~5000
3000~5000
3600~5000
3000~5000
3000-~500 0
3000~5000
1000~1400
10001400
1000~1400
GB 15230—94
GB 15230—94
Standard number
Lintel level
Lintel height, mm
Lintel width, mm
Lintel length, mm
Prestressed lintel
3.5.1.2 The codes for concrete lintels are as follows: G
GB 15230--94
Standard number
Lintel level
Lintel height, mm
Lintel width, mm
Lintel length, mm
Concrete lintel
3.5.2 Balcony beam
The codes for balcony beams are as follows:
240/150
GB 15230--94
Standard number
Balcony beam level
Balcony beam height/tip height, mm
Balcony beam width, mm
Balcony beam length, mm
Balcony beam
3.5.3 Treads
3.5.3.1 Concrete + flat treads are as follows: 258
GB1523094
GB 15230--94
Standard number
Tread level
Tread height, mm
Tread width, mm
Tread length, mm
Concrete flat treads
3.5.3.2 Prestressed L-type treads are as follows: YLTB
GB 15230—94
Standard number
Step board level
Step board thickness, mm
Step board height, mm
Step board width, mm
Step board length, mm
Prestressed L-type step board
3.5.3.3 Concrete L-type step board is as follows: LTB
GB 15230---94
Standard number
Step board level
Step board thickness, mm
Step board height, mm
Step board width, mm
Step board length, mm
Concrete L-type step board
4 Technical requirements
4.1 Raw materials
4.1.1 The production of prestressed concrete supporting components for farmhouses should adopt silicate cement, ordinary silicate cement or slag silicate cement with a grade not less than 425; the production of reinforced concrete supporting components for farmhouses should adopt ordinary silicate cement or slag silicate hot cement with a grade not less than 325, and its performance should comply with the provisions of GB175 and GB1344 respectively. 4.1.2 The sand used in the production of concrete supporting components for farmhouses should comply with the provisions of GB/T14684. 259
GB15230-94
4.1.3 Crushed stone or pebbles can be used as coarse aggregates for the production of supporting concrete components for farmhouses. Their performance should comply with the provisions of GB/T14685, and their maximum particle size should comply with the relevant provisions of GBJ204. 4.1.4 The water used for mixing and curing supporting concrete components for farmhouses should comply with the requirements of JGJ63. 4.1.5 The performance of admixtures used in the production of supporting concrete components for farmhouses should comply with the provisions of GB8076. 4.1.6 The performance of hot-rolled steel bars or cold-drawn low-carbon steel wires used in the production of supporting concrete components for farmhouses should comply with the specifications of GB1499 or 1GJ19 respectively.
4.2 Concrete strength
4.2.1 The concrete strength grade designed for the prestressed concrete supporting components of the clothing room shall not be lower than C30; the concrete strength grade designed for the reinforced concrete supporting components of the farmhouse shall not be lower than C20. 4.2.2 The compressive strength of the concrete cured under the same conditions as the components when the prestressed tendons are released shall not be lower than 75% of the concrete design strength grade. 4.2.3 The compressive strength of the concrete at 28 days under standard curing conditions shall meet the requirements of GBJ107. 4.2.4 When the supporting components leave the factory, the compressive strength of the concrete cured under the same conditions as the components shall not be lower than the designed concrete strength grade. 4.3 Structural requirements
4.3.1 The thickness of the main reinforcement protection layer of the prestressed treads and prestressed lintels with a height of no more than 60 mm shall not be less than 15 mm, the thickness of the main reinforcement protection layer of the lintels and balcony beams with a height of more than 60 mm shall not be less than 20 mm, and the thickness of the main reinforcement protection layer of the concrete treads shall not be less than 10 mm.
4.3.2 The reinforcement, welding, binding and installation of steel bars shall comply with the relevant provisions of GBI204. 4.4 Requirements for applying prestressing force
When cold-drawn low-carbon steel wire is used to apply prestressing force, it shall comply with the corresponding provisions of JGJ19. 4.5 Appearance quality and geometric dimensions
The allowable deviations of the appearance quality and geometric dimensions of supporting components shall comply with the requirements of Table 6. Table 6 Appearance quality and size allowable deviation
Missing corners and edges
Honeycombed surface
Not allowed
Not allowed
Not allowed
Not allowed
Not allowed
Not allowed
Not more than 3% of the area of ​​the same surface
Qualified products
Not allowed
Not allowed
Not more than 1 place for each piece
Not more than 3% of the area of ​​the same surface
Main reinforcement protection
Thickness of layer
GB 15230--94
Continued Table 6
Lateral bending
Surface flatness
Diagonal difference
Centre displacement of reserved holes
Note: Diagonal difference is only applicable to stepping plates. Fill
≤L/1000
Not more than 5 within 2m length
Qualified products
Not more than 7 within 2m length
4.6 Mechanical properties
The mechanical properties of prestressed concrete supporting components shall include bearing capacity, deflection and crack resistance tests; the mechanical properties of reinforced concrete supporting components shall include bearing capacity, deflection and crack width tests. 4.6.1 Bearing capacity
The bearing capacity shall comply with the requirements of formula (1):
Yo ≥Y,www.bzxz.net
Where: \--The measured value of the bearing capacity test coefficient of the component, that is, the ratio of the measured load value to the load design value (including self-weight) when the test reaches one of the test marks listed in Table 7. 【,}--The allowable value of the bearing capacity test coefficient of the component, which shall be taken according to Table 7. . -----The importance coefficient of the structural component, for supporting components, is taken. 1.261
Stress conditions
Shear of flexural members
4.6.2 Deflection
GB15230-94
Table 7 Allowable values ​​of member bearing capacity inspection coefficients [u Inspection signs for members reaching the bearing capacity limit The maximum crack width at the tension main reinforcement reaches 1.5mm or the deflection reaches 1/50 of the span
Concrete failure in the compression zone, at which time the maximum crack width at the tension main reinforcement is less than 1.5mm and the deflection is less than 1/50 of the span
Tension main reinforcement is broken
The oblique crack on the belly reaches 1.5mm, or the compressive concrete at the end of the oblique crack is shear-compressed and damaged 『～I grade steel bars
1 grade steel bars
Oblique compression failure of concrete along the oblique section, slippage of the tension main reinforcement at the end or other anchorage failure The deflection should meet the requirements of formulas (2) and (3): aTa
Ta.) = Ma()+M(ai)
·（2)
Formula: α\-The measured value of the short-term deflection of the component under the short-term test load in normal use, mm, calculated according to the provisions of Appendix A; [a.]-The allowable value of the short-term deflection of the component. mm; M.-The bending moment value calculated according to the combination of short-term effects of loads, kN·m; Mml.--The bending moment value calculated according to the combination of long-term effects of loads, kN·m; 9-The coefficient of influence of the long-term effect combination of loads on the increase of deflection is considered, and for supporting components, it is generally taken as =2; The allowable value of the deflection of the component, for lintels and step boards, take Cat} as 1/200 of its calculated span; for balcony beams, take [at as [an]
and 1/125 of the calculated span.
4.6.3 Cracking resistance
The cracking resistance test of components shall comply with the requirements of formula (4) and (5): (4)
[,] = 0. 95 °x + f
（5）
Wherein: ...·The measured value of the cracking resistance test coefficient of the component, that is, the ratio of the measured value of the load when the first crack appears on the component during the test to the short-term load test value (including self-weight) in normal use; [Allowable value of the cracking resistance test coefficient of the component; as
Normal stress of concrete at the cracking resistance test edge under the short-term effect combination of loads, N/mm; -Plastic influence coefficient of concrete in the tension zone, generally taken as 1.75 for supporting components; Cpet
-Calculated value of concrete precompression stress at the cracking resistance test edge during the test, N/mm; -Standard value of concrete tensile strength when testing components, N/mm2. 4.6.4 Crack width
The crack width test of the component shall comply with the requirements of formula (6): 262
5.2.2.2 Static loading method
GB15230—94
The mechanical properties of the balcony beam are tested by the short-term static loading test method. When the uniformly distributed load is used (Figure 5a), 9 is the permanent load and variable load borne by the balcony beam (N/m), P, is the deadweight of the balcony railing (N); when two equivalent concentrated loads are used instead of the uniformly distributed load, and Xing, (N); when two equivalent concentrated loads are used instead of the uniformly distributed load and the railing concentrated P, when it is loaded as a concentrated load alone (Figure 5b), p2= load (Figure 5c), P=P2+Pt.
The test method and steps shall be carried out in accordance with the provisions of ZBQ14002.4. 6 Inspection rules
6.1 Inspection items
6.1.1 Factory inspection: including concrete strength, appearance quality and geometric dimensions of components. 6.1.2 Type test: including concrete strength, appearance quality, geometric dimensions and mechanical properties of components. 6.2 Factory inspection
6.2.1 Batch
100 pieces of components of different varieties and types are considered as a batch, and those less than 100 pieces are also considered as inspection batches. 6.2.2 Sampling method
6.2.2.1 The number of test pieces for testing the compressive strength of concrete shall comply with the following provisions: a. The number of test pieces used to test the design strength grade of concrete shall not be less than 10 groups per quarter under the same raw materials, mix ratio and the same process conditions;
b. The number of test pieces used to test the prestressing release and factory strength shall be formed at least 2 groups per production shift. 6.2.2.2 Appearance quality inspection shall randomly select 5 pieces from the same batch. 6.2.2.3 Five pieces shall be randomly selected from the same batch for geometric size inspection. 6.3 Type inspection
6.3.1 Type inspection is required in any of the following situationsa.
When a new product is put into production;
Type inspection is carried out once a year during normal production;c.
When there are major changes in structure, materials, and processes during production that may affect the performance of components;d.
When production is resumed after a long period of suspension;
When the quality supervision agency requires type inspection. The batch and sampling methods for concrete strength, appearance quality and geometric size during type inspection shall be carried out in accordance with the provisions of Article 6.2. 6.3.3 Mechanical properties test is carried out by randomly selecting one piece from the same batch for inspection. 6.4 Judgment rules
6.4.1 Concrete compressive strength
The 28d compressive strength under standard curing conditions shall meet the requirements of GBJ107. 6.4.2 Appearance quality
The appearance quality of each component, including exposed reinforcement, cracks and holes, meets the requirements of the corresponding grade in Table 6. If only one of the other items does not meet the requirements of the corresponding grade in Table 6, the component shall be judged as the corresponding grade. 6.4.3 Geometric dimensions
If only one of the geometric dimensions of the component, including height, lateral bending and main reinforcement protective layer thickness, does not meet the requirements of the corresponding grade in Table 6, and only one of the other items does not meet the requirements of the corresponding grade, the component shall be judged as the corresponding grade. 6.4.4 Mechanical properties
The mechanical properties of the component shall meet the requirements specified in 4.6 of this standard. However, when the bearing capacity and crack resistance test coefficient of the specimen only reach 0.95 of the specified allowable value and the deflection reaches 1.10 times the specified allowable value, two more specimens may be sampled for inspection. When the first specimen meets the requirements of 261 of this standard2 Deflection
GB15230-94
Table 7 Allowable values ​​of component bearing capacity inspection coefficient [u Inspection signs for components reaching the bearing capacity limit value The maximum crack width at the tension main reinforcement reaches 1.5mm or the deflection reaches 1/50 of the span
Concrete failure in the compression zone, at which time the maximum crack width at the tension main reinforcement is less than 1.5mm and the deflection is less than 1/50 of the span
Tension main reinforcement is broken
The oblique crack on the belly reaches 1.5mm, or the compressive concrete at the end of the oblique crack is shear-compressed and damaged 『～I grade steel bars
1 grade steel bars
Oblique compression failure of concrete along the oblique section, slippage of the tension main reinforcement at the end or other anchorage failure The deflection should meet the requirements of formula (2) and (3): aTa
Ta.)= Ma()+M(ai)
·（2)
Formula: α\-The measured value of the short-term deflection of the component under the short-term test load in normal use, mm, calculated according to the provisions of Appendix A; [a.]-The allowable value of the short-term deflection of the component. mm; M.-The bending moment value calculated according to the combination of short-term effects of loads, kN·m; Mml.--The bending moment value calculated according to the combination of long-term effects of loads, kN·m; 9-The coefficient of influence of the long-term effect combination of loads on the increase of deflection is considered, and for supporting components, it is generally taken as =2; The allowable value of the deflection of the component, for lintels and step boards, take Cat} as 1/200 of its calculated span; for balcony beams, take [at as [an]
and 1/125 of the calculated span.
4.6.3 Cracking resistance
The cracking resistance test of components shall comply with the requirements of formula (4) and (5): (4)
[,] = 0. 95 °x + f
（5）
Wherein: ...·The measured value of the cracking resistance test coefficient of the component, that is, the ratio of the measured value of the load when the first crack appears on the component during the test to the short-term load test value (including self-weight) in normal use; [Allowable value of the cracking resistance test coefficient of the component; as
Normal stress of concrete at the cracking resistance test edge under the short-term effect combination of loads, N/mm; -Plastic influence coefficient of concrete in the tension zone, generally taken as 1.75 for supporting components; Cpet
-Calculated value of concrete precompression stress at the cracking resistance test edge during the test, N/mm; -Standard value of concrete tensile strength when testing components, N/mm2. 4.6.4 Crack width
The crack width test of the component shall comply with the requirements of formula (6): 262
5.2.2.2 Static loading method
GB15230—94
The mechanical properties of the balcony beam are tested by the short-term static loading test method. When the uniformly distributed load is used (Figure 5a), 9 is the permanent load and variable load borne by the balcony beam (N/m), P, is the deadweight of the balcony railing (N); when two equivalent concentrated loads are used instead of the uniformly distributed load, and Xing, (N); when two equivalent concentrated loads are used instead of the uniformly distributed load and the railing concentrated P, when it is loaded as a concentrated load alone (Figure 5b), p2= load (Figure 5c), P=P2+Pt.
The test method and steps shall be carried out in accordance with the provisions of ZBQ14002.4. 6 Inspection rules
6.1 Inspection items
6.1.1 Factory inspection: including concrete strength, appearance quality and geometric dimensions of components. 6.1.2 Type test: including concrete strength, appearance quality, geometric dimensions and mechanical properties of components. 6.2 Factory inspection
6.2.1 Batch
100 pieces of components of different varieties and types are considered as a batch, and those less than 100 pieces are also considered as inspection batches. 6.2.2 Sampling method
6.2.2.1 The number of test pieces for testing the compressive strength of concrete shall comply with the following provisions: a. The number of test pieces used to test the design strength grade of concrete shall not be less than 10 groups per quarter under the same raw materials, mix ratio and the same process conditions;
b. The number of test pieces used to test the prestressing release and factory strength shall be formed at least 2 groups per production shift. 6.2.2.2 Appearance quality inspection shall randomly select 5 pieces from the same batch. 6.2.2.3 Five pieces shall be randomly selected from the same batch for geometric size inspection. 6.3 Type inspection
6.3.1 Type inspection is required in any of the following situationsa.
When a new product is put into production;
Type inspection is carried out once a year during normal production;c.
When there are major changes in structure, materials, and processes during production that may affect the performance of components;d.
When production is resumed after a long period of suspension;
When the quality supervision agency requires type inspection. The batch and sampling methods for concrete strength, appearance quality and geometric size during type inspection shall be carried out in accordance with the provisions of Article 6.2. 6.3.3 Mechanical properties test is carried out by randomly selecting one piece from the same batch for inspection. 6.4 Judgment rules
6.4.1 Concrete compressive strength
The 28d compressive strength under standard curing conditions shall meet the requirements of GBJ107. 6.4.2 Appearance quality
The appearance quality of each component, including exposed reinforcement, cracks and holes, meets the requirements of the corresponding grade in Table 6. If only one of the other items does not meet the requirements of the corresponding grade in Table 6, the component shall be judged as the corresponding grade. 6.4.3 Geometric dimensions
If only one of the geometric dimensions of the component, including height, lateral bending and main reinforcement protective layer thickness, does not meet the requirements of the corresponding grade in Table 6, and only one of the other items does not meet the requirements of the corresponding grade, the component shall be judged as the corresponding grade. 6.4.4 Mechanical properties
The mechanical properties of the component shall meet the requirements specified in 4.6 of this standard. However, when the bearing capacity and crack resistance test coefficient of the specimen only reach 0.95 of the specified allowable value and the deflection reaches 1.10 times the specified allowable value, two more specimens may be sampled for inspection. When the first specimen meets the requirements of 261 of this standard2 Deflection
GB15230-94
Table 7 Allowable values ​​of component bearing capacity inspection coefficient [u Inspection signs for components reaching the bearing capacity limit value The maximum crack width at the tension main reinforcement reaches 1.5mm or the deflection reaches 1/50 of the span
Concrete failure in the compression zone, at which time the maximum crack width at the tension main reinforcement is less than 1.5mm and the deflection is less than 1/50 of the span
Tension main reinforcement is broken
The oblique crack on the belly reaches 1.5mm, or the compressive concrete at the end of the oblique crack is shear-compressed and damaged 『～I grade steel bars
1 grade steel bars
Oblique compression failure of concrete along the oblique section, slippage of the tension main reinforcement at the end or other anchorage failure The deflection should meet the requirements of formula (2) and (3): aTa
Ta.)= Ma()+M(ai)
·（2)
Formula: α\-The measured value of the short-term deflection of the component under the short-term test load in normal use, mm, calculated according to the provisions of Appendix A; [a.]-The allowable value of the short-term deflection of the component. mm; M.-The bending moment value calculated according to the combination of short-term effects of loads, kN·m; Mml.--The bending moment value calculated according to the combination of long-term effects of loads, kN·m; 9-The coefficient of influence of the long-term effect combination of loads on the increase of deflection is considered, and for supporting components, it is generally taken as =2; The allowable value of the deflection of the component, for lintels and step boards, take Cat} as 1/200 of its calculated span; for balcony beams, take [at as [an]
and 1/125 of the calculated span.
4.6.3 Cracking resistance
The cracking resistance test of components shall comply with the requirements of formula (4) and (5): (4)
[,] = 0. 95 °x + f
（5）
Wherein: ...·The measured value of the cracking resistance test coefficient of the component, that is, the ratio of the measured value of the load when the first crack appears on the component during the test to the short-term load test value (including self-weight) in normal use; [Allowable value of the cracking resistance test coefficient of the component; as
Normal stress of concrete at the cracking resistance test edge under the short-term effect combination of loads, N/mm; -Plastic influence coefficient of concrete in the tension zone, generally taken as 1.75 for supporting components; Cpet
-Calculated value of concrete precompression stress at the cracking resistance test edge during the test, N/mm; -Standard value of concrete tensile strength when testing components, N/mm2. 4.6.4 Crack width
The crack width test of the component shall comply with the requirements of formula (6): 262
5.2.2.2 Static loading method
GB15230—94
The mechanical properties of the balcony beam are tested by the short-term static loading test method. When the uniformly distributed load is used (Figure 5a), 9 is the permanent load and variable load borne by the balcony beam (N/m), P, is the deadweight of the balcony railing (N); when two equivalent concentrated loads are used instead of the uniformly distributed load, and Xing, (N); when two equivalent concentrated loads are used instead of the uniformly distributed load and the railing concentrated P, when it is loaded as a concentrated load alone (Figure 5b), p2= load (Figure 5c), P=P2+Pt.
The test method and steps shall be carried out in accordance with the provisions of ZBQ14002.4. 6 Inspection rules
6.1 Inspection items
6.1.1 Factory inspection: including concrete strength, appearance quality and geometric dimensions of components. 6.1.2 Type test: including concrete strength, appearance quality, geometric dimensions and mechanical properties of components. 6.2 Factory inspection
6.2.1 Batch
100 pieces of components of different varieties and types are considered as a batch, and those less than 100 pieces are also considered as inspection batches. 6.2.2 Sampling method
6.2.2.1 The number of test pieces for testing the compressive strength of concrete shall comply with the following provisions: a. The number of test pieces used to test the design strength grade of concrete shall not be less than 10 groups per quarter under the same raw materials, mix ratio and the same process conditions;
b. The number of test pieces used to test the prestressing release and factory strength shall be formed at least 2 groups per production shift. 6.2.2.2 Appearance quality inspection shall randomly select 5 pieces from the same batch. 6.2.2.3 Five pieces shall be randomly selected from the same batch for geometric size inspection. 6.3 Type inspection
6.3.1 Type inspection is required in any of the following situationsa.
When a new product is put into production;
Type inspection is carried out once a year during normal production;c.
When there are major changes in structure, materials, and processes during production that may affect the performance of components;d.
When production is resumed after a long period of suspension;
When the quality supervision agency requires type inspection. The batch and sampling methods for concrete strength, appearance quality and geometric size during type inspection shall be carried out in accordance with the provisions of Article 6.2. 6.3.3 Mechanical properties test is carried out by randomly selecting one piece from the same batch for inspection. 6.4 Judgment rules
6.4.1 Concrete compressive strength
The 28d compressive strength under standard curing conditions shall meet the requirements of GBJ107. 6.4.2 Appearance quality
The appearance quality of each component, including exposed reinforcement, cracks and holes, meets the requirements of the corresponding grade in Table 6. If only one of the other items does not meet the requirements of the corresponding grade in Table 6, the component shall be judged as the corresponding grade. 6.4.3 Geometric dimensions
If only one of the geometric dimensions of the component, including height, lateral bending and main reinforcement protective layer thickness, does not meet the requirements of the corresponding grade in Table 6, and only one of the other items does not meet the requirements of the corresponding grade, the component shall be judged as the corresponding grade. 6.4.4 Mechanical properties
The mechanical properties of the component shall meet the requirements specified in 4.6 of this standard. However, when the bearing capacity and crack resistance test coefficient of the specimen only reach 0.95 of the specified allowable value and the deflection reaches 1.10 times the specified allowable value, two more specimens may be sampled for inspection. When the first specimen meets the requirements of 261 of this standard2 Static loading method
GB15230—94
The mechanical properties of balcony beams are tested by short-term static loading test method. When uniformly distributed load is used (Figure 5a), 9 is the permanent load and variable load borne by the balcony beam (N/m), P, is the deadweight of the balcony railing (N); when two equivalent concentrated loads are used to replace the uniformly distributed load, and Xing, (N); when two equivalent concentrated loads are used to replace the uniformly distributed load and the railing concentrated P, when loaded as a concentrated load alone (Figure 5b), p2= load (Figure 5c), P=P2+Pt.
The test method and steps shall be carried out in accordance with the provisions of ZBQ14002.4. 6 Inspection rules
6.1 Inspection items
6.1.1 Inspection 1: including concrete strength, appearance quality and geometric dimensions of components. 6.1.2 Type test: including concrete strength, component appearance quality, geometric dimensions and mechanical properties. 6.2 Factory inspection
6.2.1 Batch
100 pieces of components of different varieties and types are considered as a batch, and those less than 100 pieces are also considered as an inspection batch. 6.2.2 Sampling method
6.2.2.1 The number of test pieces for testing the compressive strength of concrete shall comply with the following provisions: a. The number of test pieces used to test the design strength grade of concrete shall not be less than 10 groups per quarter under the same raw materials, mix ratio and the same process conditions;
b. The number of test pieces used to test prestressing release and factory strength shall be formed at least 2 groups per production shift. 6.2.2.2 Appearance quality inspection shall randomly select 5 pieces from the same batch. 6.2.2.3 Geometric size inspection shall randomly select 5 pieces from the same batch. 6.3 Type inspection
6.3.1 Type inspection is required in any of the following situationsa.
When a new product is put into production;
Type inspection is carried out once a year during normal production;c.
During production, if there are major changes in structure, materials, and processes that may affect the performance of components;d.
When production is resumed after a long period of suspension;
When the quality supervision agency requires type inspection. The batch and sampling methods for concrete strength, appearance quality and geometric dimensions during type inspection shall be carried out in accordance with the provisions of Article 6.2. 6.3.3 Mechanical properties test One piece is randomly selected from the same batch for inspection. 6.4 Judgment rules
6.4.1 Concrete compressive strength
The 28d compressive strength under standard curing conditions shall meet the requirements of GBJ107. 6.4.2 Appearance quality
The appearance quality of each component, including exposed reinforcement, cracks and holes, meets the requirements of the corresponding grade in Table 6. If only one of the other items does not meet the requirements of the corresponding grade in Table 6, the component shall be judged as the corresponding grade. 6.4.3 Geometric dimensions
If only one of the geometric dimensions of the component, including height, lateral bending and main reinforcement protective layer thickness, does not meet the requirements of the corresponding grade in Table 6, and only one of the other items does not meet the requirements of the corresponding grade, the component shall be judged as the corresponding grade. 6.4.4 Mechanical properties
The mechanical properties of the component shall meet the requirements specified in 4.6 of this standard. However, when the bearing capacity and crack resistance test coefficient of the specimen only reach 0.95 of the specified allowable value and the deflection reaches 1.10 times the specified allowable value, two more specimens may be sampled for inspection. When the first specimen meets the requirements of 261 of this standard2 Static loading method
GB15230—94
The mechanical properties of balcony beams are tested by short-term static loading test method. When uniformly distributed load is used (Figure 5a), 9 is the permanent load and variable load borne by the balcony beam (N/m), P, is the deadweight of the balcony railing (N); when two equivalent concentrated loads are used to replace the uniformly distributed load, and Xing, (N); when two equivalent concentrated loads are used to replace the uniformly distributed load and the railing concentrated P, when loaded as a concentrated load alone (Figure 5b), p2= load (Figure 5c), P=P2+Pt.
The test method and steps shall be carried out in accordance with the provisions of ZBQ14002.4. 6 Inspection rules
6.1 Inspection items
6.1.1 Inspection 1: including concrete strength, appearance quality and geometric dimensions of components. 6.1.2 Type test: including concrete strength, component appearance quality, geometric dimensions and mechanical properties. 6.2 Factory inspection
6.2.1 Batch
100 pieces of components of different varieties and types are considered as a batch, and those less than 100 pieces are also considered as an inspection batch. 6.2.2 Sampling method
6.2.2.1 The number of test pieces for testing the compressive strength of concrete shall comply with the following provisions: a. The number of test pieces used to test the design strength grade of concrete shall not be less than 10 groups per quarter under the same raw materials, mix ratio and the same process conditions;
b. The number of test pieces used to test prestressing release and factory strength shall be formed at least 2 groups per production shift. 6.2.2.2 Appearance quality inspection shall randomly select 5 pieces from the same batch. 6.2.2.3 Geometric size inspection shall randomly select 5 pieces from the same batch. 6.3 Type inspection
6.3.1 Type inspection is required in any of the following situationsa.
When a new product is put into production;
Type inspection is carried out once a year during normal production;c.
During production, if there are major changes in structure, materials, and processes that may affect the performance of components;d.
When production is resumed after a long period of suspension;
When the quality supervision agency requires type inspection. The batch and sampling methods for concrete strength, appearance quality and geometric dimensions during type inspection shall be carried out in accordance with the provisions of Article 6.2. 6.3.3 Mechanical properties test One piece is randomly selected from the same batch for inspection. 6.4 Judgment rules
6.4.1 Concrete compressive strength
The 28d compressive strength under standard curing conditions shall meet the requirements of GBJ107. 6.4.2 Appearance quality
The appearance quality of each component, including exposed reinforcement, cracks and holes, meets the requirements of the corresponding grade in Table 6. If only one of the other items does not meet the requirements of the corresponding grade in Table 6, the component shall be judged as the corresponding grade. 6.4.3 Geometric dimensions
If only one of the geometric dimensions of the component, including height, lateral bending and main reinforcement protective layer thickness, does not meet the requirements of the corresponding grade in Table 6, and only one of the other items does not meet the requirements of the corresponding grade, the component shall be judged as the corresponding grade. 6.4.4 Mechanical properties
The mechanical properties of the component shall meet the requirements specified in 4.6 of this standard. However, when the bearing capacity and crack resistance test coefficient of the specimen only reach 0.95 of the specified allowable value and the deflection reaches 1.10 times the specified allowable value, two more specimens may be sampled for inspection. When the first specimen meets the requirements of 261 of this standard
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