Some standard content:
UDC666.981:001.4
National Standard of the People's Republic of China
GB458284
Terms and their definition of ferrocementPublished on July 20, 1984
Implementation on June 1, 1985
Approved by the State Bureau of Standards
Basic name
Constituent materials
Production process and special equipment
Quality control and inspection
Performance and test methods
6 Calculation and its parameters
Chinese index
English index
（1）
（2）
（4）
National Standard of the People's Republic of China
Terms and their definition
of ferrocement
This standard is applicable to teaching, scientific research, design, production, inspection, compilation and translation of technical documents. 1 Basic name
1.1 Ferrocement
ferrocement
UDC666.981
GB4582-84
A thin-walled structural material made of steel mesh or steel mesh and reinforcement as reinforcement material and cement mortar as base material. 1.1.1 All mesh ferrocement
Ferrocement with only steel mesh and no reinforcement. Reinforced ferrocement
Ferrocement with skeletal bar Ferrocement with both steel mesh and reinforcement. Self-stressing ferrocement
Self-stressing ferrocement
Ferrocement with self-stressing cement mortar as base material, using the expansion performance of self-stressing cement during the hardening process to tension reinforcement and steel mesh, so that the cement mortar obtains pre-stressed ferrocement. 1.3 Prestressed ferrocement
prestressed ferrocement
Ferrocement that obtains prestressed stress in cement mortar through tensioning and reinforcement. 1.4. Lightweight ferrocement
Lightweight ferrocementbzxz.net
Ferrocement that uses lightweight cement mortar as the base material. 2 Composition materials
2.1 Base material
matrix
The continuous phase in the composite material, here refers to the cement mortar in the ferrocement. 2.1.1 Cement mortar
cement mortar
A mixture made of cement, sand and water or a certain amount of admixtures in appropriate proportions. 2.1.2 Self-stressing cement mortar
Self-stressing cement mortarCement mortar with self-stressing cement as the binder. Issued by the National Bureau of Standards on July 20, 1984
Implemented on June 1, 1985
2.1.3 Lightweight cement mortar
lightweight cement mortar
GB4582-84
Cement mortar with natural or artificial light sand with a loose bulk density not exceeding 1200kg/m3 as fine aggregate, its bulk density is generally not more than 1800kg/m3.
Reinforcer
Reinforcer
The dispersed phase in the composite material that plays a reinforcing role, here refers to the wire mesh and reinforcement in ferrocement 2.2.1 Wire mesh
wiremesh
Use the mesh diameter of 0.5-2mm, the mesh size of 5-25mm, and the mesh shape of square or rectangular, as the galvanized or non-galvanized reinforcement material for ferrocement dispersed reinforcement. 2.2.1.1 Woven mesh
wovenmesh
Wire mesh made of cold-drawn low-carbon steel wire with a single-filament strength of not less than 4500kg/cm2 through a weaving process. 2.2.1.2 Welded mesh
Welded mesh
Wire mesh made of cold-drawn low-carbon steel wire with a single-filament strength of not less than 4500kgf/cm2 through a welding process. 2.2.2 Reinforcement
Skeletal bar
Cold-drawn low-carbon steel wire or steel bar added between the layers of ferrocement mesh. The diameter of the cold-drawn low-carbon steel wire used for reinforcement is usually 2~5mm, and the diameter of the steel bar used for reinforcement is 6~8mm. 2.2.2.1 Longitudinal bar
Longitudinal bar
Reinforcement arranged along the length direction of the ferrocement board. Transverse bar
Transverse bar
Reinforcement arranged along the width direction of the steel mesh cement board. 3 Production process and special equipment
3.1 Mesh-bar placement and tying
Mesh-bar placement and tying The construction process of laying wire mesh and reinforcement according to design requirements, and tying the reinforcement and mesh. 3.2 Manual plastering
manual plastering
The whole process of filling cement mortar into the reinforcement mesh skeleton by manual molding method to compact, smooth and finish it. 3.2.1 Compacting
compacting
The molding process of pressing cement mortar into the reinforcement mesh skeleton to make it dense. 3.2.2 Smoothing
The molding process of leveling the surface of the compacted mortar and controlling the thickness of the protective layer before the cement initially sets. 3.2.3 Finishing
Finishing
When the cement is close to final setting, the smoothed mortar surface is pressed hard to make it smooth and clean. 2
3.3 Vibration molding process
GB4582-84
vibro-moulding process
Using a vibrating machine to make the cement mortar flow and compact under the action of vibration force to make the steel mesh cement product of the required shape.
3.4 Vibration stamping process
vibrating stamping process
Using a vibrating stamping machine to make the cement mortar flow and fill the space between the male and female molds and compact it under the combined action of vibration force and mold pressure to make the steel mesh cement product of the required shape. Battery-mold process
Battery-mold process
A molding process that uses battery-molds and vibrating machinery to vertically produce steel mesh cement plate-shaped components. '3.6 Vibration-vacuum dewatering process
Vibrating vacuum - dewatering processA molding process that uses vibration and vacuum dewatering equipment to mold steel mesh cement products, and then vacuum dehydrates them on the basis of vibration compaction to make the cement mortar more dense. 3.7 High frequency vibrating process with hopper
High frequency vibrating process with hopperA vertical molding process that uses an open hopper with a high-frequency vibrator inserted to press tightly on the reinforcement network skeleton, and through continuous feeding and movement, the cement mortar flows and fills the reinforcement network skeleton and makes it dense under the action of high-frequency vibration force. Outer mold vibrating process
Outer mold vibrating process uses a vibrator attached to the outer mold to make the cement mortar flow and fill the mesh skeleton between the inner and outer molds under the action of vibration force to make it dense. A molding process for integrally forming the steel wire mesh cement shell. 3.9 Shotcreting process
Shotcreting process
Use a mortar pump to inject and press the cement mortar into the mesh skeleton with compressed air to make it dense. 3.10 Weaving machine
Weaving machine of mesh
Use the weaving principle to weave steel wire mesh by moving the grate up and down and the left and right crossing shuttles. 3.11
Welding machine of mesh
Welding machine of mesh
Use low voltage and strong current to weld the cross nodes of the steel wire mesh together, and specialize in spot welding of welding mesh. 3.12 Pneumatic tool for tying bar and mesh It is composed of a compressed air machine and a special tying gun, and is a machine used to tie and fix the bar mesh frame. 3.13 Bar and mesh welding system with storing energy condenser It is composed of an electric welder and a special welding gun, and is an electromechanical device used to weld the bar mesh frame of wire mesh cement products. 3.14 Vibrating stamping press It is composed of a punch with a vibrator and a certain shape, size and weight as the positive mold, and a female mold with the corresponding shape and size to form a mechanical equipment specially used for vibration molding and compacting steel mesh cement products. 3.15
High frequency vibrating tool with hopper3
GB4582-84
A special mechanical device for vertically forming steel wire mesh cement products, which is composed of a high-frequency vibrator, a material box and a lifting tool.
4 Quality control and inspection
4.1 Water-cement ratio (W/C)
water-cementratio
The weight ratio of water W to cement C in cement mortar. 4.2 Cement-sand ratio (C/S)
cement-sand ratio
The weight ratio of cement C to sand S in cement mortar. 4.3 Sand grading
Sand grading
The distribution of sand particles of each grade in the sand sample. 4.3.1 Sand grading curve
sand grading curve
The curve is drawn with the cumulative percentage of the residue on each level on the standard sand sieve as the ordinate and the sieve hole size as the abscissa to visually judge the composition of sand particles.
Sand grading standard region
Sand grading standard region is used to measure the standard area of sand particle gradation. 4.4 Fineness modulus (Mx)
fineness modulus
An indicator of the coarseness and fineness of sand particles. It is determined by the screening results of the standard sand sieve according to formula (1): Mx=(A + A + A + As + As) - 5 A100 - A
Wherein: A1, A2, A3, A4, A5, A6——The cumulative percentage of the residue on each sieve with the sieve hole size of 5, 2.5, 1.25, 0.63, 0.315, 0.16 mm, respectively. 4.5 Maximum size of sand (dmax)
maximum size of sand
The maximum allowable size of sand determined by the thickness of the mortar protective layer, the mesh size and the thickness of the wire mesh cement board. 4.6 Mortar consistency
Mortar consistency
Indicates the flow performance of cement mortar under its own weight or external force, with the cone sinking depth measured by the mortar consistency meter as an indicator, and the unit is cm.
Mortar strength
Mortar strength
Refers to the compressive strength of cement mortar measured after a certain age of curing of a cubic specimen with a side length of 7.07cm, and the unit is 1gf/cm2. 4.8 Honeycomb
honeycomb
A molding quality defect in which honeycomb holes are exposed on the surface of the wire mesh cement due to insufficient vibration or leakage of mortar caused by loose formwork.
4.9 Blisters
air pockets
GB4582-84
A molding quality defect caused by the failure to remove all internal bubbles or premature polishing, resulting in a floating slurry shell on the surface of the wire mesh cement product that will fall off at the first blow.
4.10 Sandwich
A molding quality defect caused by insufficient slurry application and insufficient vibration. 4.11 Scaling
A molding quality defect caused by the failure to remove all internal bubbles or excessive oiling of the template, resulting in the formation of blisters and pitting on the surface of the wire mesh cement product.
4.12 Surface dusting
A quality defect caused by the poor bonding between cement and sand due to improper mix ratio or poor performance of cement and sand, resulting in the peeling of surface sand.
Printed mesh and imprinted ribs
traceofmeshand.bar
A quality defect in which traces of mesh and ribs are visible on the surface of ferrocement products. 4.14 Emerging wire
Emerging wire
A molding quality defect in which the wire heads of the tying rib mesh skeleton are exposed on the surface of ferrocement products. 4.15 Emerging mesh
Emerging mesh
A molding quality defect in which the mesh is exposed on the surface of ferrocement products due to insufficient thickness of the protective layer. Crack
A crack in ferrocement products caused by changes in temperature and humidity or external forces. 4.16.1 Shrinkage crack
Shrinkage crack
Shrinkage crack caused by changes in the volume of ferrocement mortar due to changes in external temperature and humidity or the influence of corrosive media in the atmosphere.
4.16.2 Stressed crack
Stressed crack
The crack on the surface of steel mesh cement products under the action of external forces. 4.17
Acetone wetting method
A method of using acetone to wipe the surface of steel mesh cement specimens to make cracks visible. Reading microscope
reading microscope
An optical measuring instrument used to measure the width of mortar cracks on the surface of steel mesh cement specimens. Standard sieve of sand
Standard sieve of sand
A sieve with standard sieve hole size, specially used to measure the composition of sand particles. Mortar consistometer
Mortar consistometer
An instrument with standard shape, size and weight, mainly composed of cone and truncated cone containers, specially used to measure the consistency of mortar.
Performance and test methods
Axial tensile property
axialtensiveproperty
GB4582-84
The crack development, strength and deformation properties of steel mesh cement specimens at various stages under the action of axial tension through the axis. 5.2Axial compressive property
axialcompressiveproperty
The crack development, strength and deformation properties of steel mesh cement specimens at various stages under the action of axial pressure through the axis. 5.3Flexural property
Flexural property
The bending mechanical properties of steel mesh cement specimens at various stages under the action of bending moment. 5.4
Impact resistance
Impact resistance
The ability of steel mesh cement specimens to resist impact. 5.5 Fatigue resistance
Fatigue resistance
The ability of steel mesh cement specimens to resist repeated loads. 5.6 Creep
The non-elastic deformation of steel mesh cement specimens that increases slowly over time under constant external force. 5.7 Shrinkage
shrinkage
The volume reduction of cement mortar due to physical and chemical effects. 5.7.1 Drying shrinkage
drying shrinkage
The volume reduction of cement mortar due to the evaporation of water in the capillaries and glue pores. 5.7.2 Temperature shrinkage
temperature shrinkage
The volume reduction of cement mortar due to a drop in temperature. 5.7.3 Carbonation shrinkage
carbonated shrinkage
The volume reduction of cement mortar due to the effect of CO in the air. 5.8 Cracking resistance
crackingresistance
The ability of ferrocement specimens to resist cracking under stress. It is expressed by the strength of the specimen when it resists the appearance of initial visible cracks, and the unit is kgf/cm2.
5.9 Impermeability
impermeability
The ability of ferrocement specimens to resist the penetration of liquids such as water and oil. It is expressed by the liquid pressure per unit area of the specimen, and the unit is kgf/cm2.
5.10 Durability
durability
The ability of ferrocement to maintain basic performance during long-term use. 6
Mortar corrosion resistance
GB4582-84
resistance to chemical attack of mortar The ability of cement mortar to resist corrosion by media such as acid, salt, and oil. Corrosion resistance of bar and mesh The ability of the bar and mesh in ferrocement to resist corrosion under chemical or electrochemical action. 5.10.3 Frost resistance The ability of ferrocement to resist freeze-thaw damage. Air impermeability The ability of ferrocement to prevent gas penetration. 5.12 Fire resistance The ability of ferrocement to maintain its performance after burning. 5.13
test method of ferrocement panels in axial tension refers specifically to the short-term static test method of unidirectional axial tension conducted on ferrocement panels with a thickness of not more than 60mm and a width of 200~300mm using a two-way adjustable fixture, see GB3692-83 "Test method of axial tension of ferrocement panels". 5.15
adjustable fixture in two directions A special machine that can adjust the eccentricity in the front, back, left and right directions to make the ferrocement panels under axial tension. Flexural test device
Flexural test device
A flexural test device that can make the middle part of the ferrocement panel within the range of 300-400mm withstand pure bending. 6 Calculation and its parameters
6.1 Calculated thickness of ferrocement panel (h) calculated thickness of ferrocement panel The total thickness of the ferrocement panel reinforcement skeleton plus the two-sided protective layer, in mm, calculated according to formula (2): h = Zdzwi + dhwi + Edzi + Edhi + 28
Where: Zdzwi
The sum of the diameters of the longitudinal wires of each layer, mm;
The sum of the diameters of the transverse wires of each layer, mm;
The sum of the diameters of the longitudinal bars of each layer, mm;
The sum of the diameters of the transverse bars of each layer, mm;
-thickness of the mortar protective layer, mm.
6.2 Thickness of mortar coverage (8)
thickness of mortar coverage refers to the distance from the outer edge of the outermost mesh wire in the ferrocement to the mortar surface, generally 3 to 5 mm. 6.3 Mesh size
(2)
size of mesh opening
GB4582-84
Parameter used to determine the geometric shape and size of the wire mesh grid. For rectangular and square grids, it is expressed by the length of the grid side. 6.4
Reinforcement spacing (S,)
bar spacing
centre moment of adjacent reinforcements in the same direction and layer of ferrocement board, in mm. 6.4.1 Longitudinal bar spacing (Szj)
longitudinal bar spacing
the spacing of longitudinal reinforcements in the same layer of ferrocement board, in mm. 6.4.2 Transverse bar spacing (Shi)
transverse bar spacing
The spacing of transverse bars in the same layer of ferrocement slab, in mm. 6.5 Number of wire mesh layers (nw)
layer number.ofmesh
The total number of layers of wire mesh of various specifications laid in ferrocement. 6.6
Number of reinforcement layers (n)
layer number of bar
The number of layers of reinforcement of various specifications in each direction arranged in ferrocement. Number of longitudinal bar layers (nzi)
layer number of longitudinal barThe number of reinforcement layers arranged in the length direction of ferrocement. 6.6.2
Number of transverse bar layers (nhi)
layer number of transverse barThe number of reinforcement layers arranged in the width direction of ferrocement. 6.7Total
Total steel content (r)
total steel content
The total weight of steel mesh and reinforcing steel wire in every cubic meter of wire mesh cement board, in kg/m3. 6.8Steel content (G)
steel content
The total weight of reinforcement and mesh wire in the force direction in every cubic meter of wire mesh cement board, in kg/m3. 6.9Total percentage of reinforcement (μ)
total percentage of reinforcementThe sum of the reinforcement ratio μ of wire mesh cement board and the mesh wire ratio μs, expressed as a percentage. 6.9.1 Reinforcement ratio μ;
percentage of reinforcement
The ratio of the total cross-sectional area of reinforcement in the load-bearing direction of the wire mesh cement board to the cross-sectional area of the wire mesh cement board, expressed as a percentage μ (%), is calculated according to formula (3):
wherein: n is the number of stress-bearing bars in each layer;
is the cross-sectional area of a single stress-bearing bar in each layer, mm2; A is the cross-sectional area of the wire mesh cement board, mm.
6.9.2 Mesh rate (μs)
percentage of mesh
GB4582-84
The ratio of the total mesh cross-sectional area of the steel mesh cement board in the stress direction to the cross-sectional area of the steel mesh cement board, expressed as a percentage of μs (%), is calculated according to formula (4):
Number of stress-bearing wires in each layer;
Where: ns
Asi——cross-sectional area of each layer of stress-bearing single wire, mm2; A——cross-sectional area of steel mesh cement, mm2.
6.10 Reinforcement form
nsi Asi
formof reinforcement
is a simplified form that represents the configuration of steel mesh cement reinforcement (including the number of mesh layers, number of reinforcements, mesh diameter, reinforcement diameter, mesh size, (4)
reinforcement spacing,
arrangement position), expressed as follows: nu
wherein:
Sizw·Sthw
Syzw·Syhw
njw-dizw·dihw
nyw-dyzw·dyhw
number of steel mesh layers;||tt ||Number of mesh layers on the tension surface;
Number of mesh layers on the compression surface;
Diameter of longitudinal wires on the tension surface;
Diameter of transverse wires on the tension surface;
Diameter of longitudinal wires on the compression surface;
Diameter of transverse wires on the compression surface;
Grid spacing on the tension surface;
Grid spacing on the compression surface;
Number of reinforcement layers;
Number of longitudinal reinforcement layers;
Number of transverse reinforcement layers;
Diameter of longitudinal reinforcement;
Diameter of transverse reinforcement;
Spacing of longitudinal reinforcement;
Spacing of transverse reinforcement.
Sizw·Sthu
Syzw·Syhw
nzj · dzi—Szi
nhi· dhi—Shi
（5）
When ordinary steel wire mesh with a mesh diameter of 1mm and a mesh size of 10mm×10mm is used, the reinforcement form can be simplified as: nu
dispersive coeficient of reinforcement (K)
nzi ·dzi—Szi
ni·dh—Shi
dispersive coeficient of reinforcement（5）
is an indicator to measure the dispersion of steel mesh cement reinforcement. It is expressed as the ratio of reinforcement ratio, mesh ratio to corresponding reinforcement diameter and mesh diameter, with the unit of 1/mm, and is calculated according to formula (6) and (7): for unreinforced steel mesh cement
for reinforced steel mesh cement
(6)
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