Affordable housing,usually called prefabricated affordable home/house,is a kind of housing soluton that uses light structural steel as main frame,insulated panels for wall and roof cladding and bolted structure.Affordable housing has wide applications in temporary housing situation like construction labor camp,disaster relief area and lower income people considering its advantages of fast installation,cost-saving,sturdy structure and environtent friendly.

I.Affordable housing model design and plans

Affordable housing could be in various models whether in single story or multi-story,or different function rooms(bedroom,kitchen,living room,dining room,bathroom,storage room etc) based on the clients' requests.Many people may concern about the look of a affordable housing.But there could be different options for the affordable house look like coupled slope,hipped roof and even multi-slope roof.What's more,your affordable house could be even equipped with veranda,fences or posts.To sum up,a prefabricated affordable house could be in different forms just like a traditional brick or concrete house.


II.Components of a house.

The components of a affordable house mainly encompass the main frames,wall and roof panels,ceilings,doors and windows and other necessary accessories.

(1)MAIN FRAME

For a house that would be built up in less windy area,we could use the rectangle hollow section as structural column and beam.If the house would be built up in gale area,it is better that we use the H section steel.

About the surface treatment of the structural steel members,KXD provides anti-corrosive gray painted and galvanized.


(2)Wall and Roof Panel System
Prefabricated affordable houses adopt plug-in system which uses the U channel to accommodate the wall panel.For the roof,the panel could be directly fixed upon the roof structure by bolts.


About the wall and roof panel options,the most commonly used is sandwich panel which includes EPS,Fiberglas wool,Rockwool and PU.The thickness of sandwich panel is 50mm,75mm,100mm and 150mm.The followings are the differences of sandwich panel in the affordable houses:

A:EPS sandwich panel:EPS sandwich panel is commonly used for prefab house wall and roof(ceiling) panel.Considering its light density(8kg/m³,10kg/m³and 12kg/m³ options) and its non-fire proof property,EPS sandwich panel house is applicable for less windy area and the owner who has lower fire-proof requirements for the house. 

B:Fiberglass/Rock wool sandwich panel:Fiberglass or rock wool sandwich panel also could be used for the wall system and roof(ceiling) panel.With its fire-proof(rock wool has the highest level of fire-proof even better fiberglass wool),thermal insulation an higher density(60kg/m³)properties,the fiberglass or rock wool sandwich panel house could be used in gale weather area What's more,if the customer has specific request for fire-proof condition,fiberglass or rock wool would be a good option. 

C:PU sandwich panel has strong and stable structure itself and non-deformable ability due to its comprehensive higher density which could withstand >6.7KPa wind pressure and >400J impact strength.Hence PU panel for house has good wind uplift resistance capability. It is also ideal for gale or strong wind areas even in cyclone situation to use PU sandwich panel house.Like the EPS and fiberglass wool,PU panel also is used for house wall and roof(ceiling) panel.And PU panel is also fire-proof.

Besides the thermal insulated sandwich panel,KXD also provide the Cement foam and Stone Chip Coated Steel Roof Tiles.


EPS cement panel refers to a novelty in efficiency and lightweight panel reinforced with fiber cement or calcium silicate, and also filled with cement, polyethylene, ceramics, coal ashes as main material.This product can replace the red brick, brick Clay, hollow brick, mixed sandwich, gypsum blocks, perlite and perlite porous plate and other building materials, which is widely applicable in various types of wall building solutions, such as banks, offices, hospitals, schools, hotels etc. .
Regular Size:
Width: 610 mm
Thickness: 60 mm, 75 mm, 90 mm, 100 mm, 120 mm, 150 mm, 180 mm
Length: 2,270 mm, 3,000 mm (the length of the panel can be measured with the unlimited of 3,000 mm.)

Supporting installation materials cement foam panel:
(3)Ceilings,trim and other accessories.

For the ceiling,there is sandwich panel ceiling,gypsum board ceiling and PVC ceiling.Also our house is equipped with baseboards,trims and other accessories.

(4)Doors,windows and interior fittings     KXD's H Section Manufacturing Equipment and Process
Steel plate cutting→H section assembly→Automatic welding-H section strengthening→Assembly→Manual welding→Shot blasting-Painting→
Storage

I.Steel plate cutting
The H section  steel plate should be checked again by the factory and shall be applied under the condition of up to design and specified requirements after checking. Steel plate cutting should be aimed at quality guarantee and material saving. For each process like plate cutting,H type assembly, components assembly and pre-assembly should be carried out by profession setting-out worker precisely on processing surface and assembly sample plates.To guarantee the accuracy of the components'geometrical dimension,tolerance of form and position, angle and contact surface,inspection is necessary by inspector after setting out.In order to ensure the cutting quality,the surface of the ultra-thick plate is subjected to the surface carburizing hardness test before cutting.The CNC cutting equipment is preferred for cutting.The high purity 98.0% acrylic gas and 99.99% liquid oxygen gas are used to guarantee the smoothness and flatness of the cutting surface without notches and slags.The groove is cut by a special imported cutting machine.

Equipment name: Portable CNC Fire-cutting machine
Model No.: CNCDG-1530
Application feature: steel plate cutting(5-100mm plate cutting thickness), beveling of the edge.Advantageous in small equipment and easy-to-move. Mainly for cutting regular and irregular small components and beveling of the plate.

Equipment name:Straight flame cutting machine
Model No.:DZCG-4000A
Application feature:steel plate cutting(5-100mm plate cutting thickness),Y flange plate, web plate cutting, effective cutting width: 3200mm

Equipment name:CNC cutting machine
Model No.:CNC-4000C
Application feature:steel plate cutting(5-100mm plate cutting thickness),Y flange plate,web plate and irregular component cutting,effective cutting width: 3200mm

Equipment name: Radial drilling machine
Model No.:Z3050*16/1 
Application feature:Maximum drilling diameter φ50mm,Mainly for processing of component bolt-connection holes

Equipment name:Puncher machine
Model No.:JH21-400
Application feature:Maximum stamping pressure-400 ton,Mainly for plate punching, blanking, bending and shallow stretching

Equipment name:Shearing machine 
Model No.:Q11Y-25*2500 
Application feature:cutting width 2500mm and cutting thickness 3-25mm

II.H section steel assembly
The assembly process is set up on the imported H section production line.4 hydraulic positioning system press firmly against between the upper/lower flange and web plates in position. The adjust the parallelism of the flange plates and perpendicularity between flange and web plates and get them fixed after. The fixing welding should adopt C02 gas shielded welding.

Equipment name:H section steel assembly machine
Model No.:Z20B
Application feature:mainly for H type assembly u,flange width 150-800mm,web height 160-2000 mm

III.Automatic welding
The H section steel members will be hoisted into the gantry-type submerged arc automatic welding machine for welding.The welding process should be carried out in accordance with specified welding sequence and regulation parameters.Preheating, which uses the electrical heaters, is necessary for the ultra-thick plates of components.The set temperature shall be determined based on the specified one.Please see factory welding process documents for detail.

Equipment name: Gantry-type submerged arc automatic welding machine  
Model No.:LHA5ZB
Application feature:Mainly for assembly welding of H section steel whose maximum cross section up to 800mm×2000mm

IV.H section steel strengthening machine
H section steel strengthening process: Correction of flange flatness by using H section steel flange plate strengthening machine.Flame-correct the perpendicularity between the H section flange and web plate under special circumstances and then correct the side bending of the H section steel. The flame temperature should be controlled under the range of 600~800ºC.

Equipment name:H section steel strengthening machine  
Model No.:YTJ60B
Application feature:Mainly for correcting the deformation of I beam or H section steel flange plate during welding process,flange width 200-1000mm, flange thickness≤60mm, web height≥350mm

Equipment name:H section flange strengthening machine
Model No.: HYJ-800
Application feature:Mainly for correcting the deformation of I beam or H section steel flange plate during welding process,flange width 160-800mm,flange thickness≤40mm,web height≥160mm

V.Simulated assembly of component
1.Get familiar with component shop drawing and technical requirements.
2.The model components need to re-check by related department after making and finalizing of the model components and then to assemble.
3.Accurate mark-up
4.Inspect the component after first assembly.For multi-group components, pre-assembly for the first group and then batch assembly after qualified test.

VI.Manual welding

VII.Shot blasting
Equipment name:10-ramming heads shot blasting machine
Model No.:QH1525    
Application feature:Mainly for shot blasting of section steels including H section steel, welded members and steel plate,10 ramming head; Machine entry size:1500Í2500 and member at 1200Í2000 size could pass the machine at once; up to Sa2.5 Grade.

VIII.Painting
The surface of the members should be in even,flat, glossy and full painting without manifest of cracking, peeling and pin holing.The color and coating thickness should also meet design requirements.If there is no certain requirements,the following standards should be followed:thickness is 150μm indoor while 125μm outdoor.The allowable deviation is -25μm.The allowable deviation of dry paint film thickness for each-time painting
Two coats of primer:thickness being40±5μm; Two coats of finish paint:thickness being 60±5μm.

Equipment name:Airless sprayer     
Model No.:CPQ9CA
Application feature: Derived capacity:56 L/min,Air consumption:50~1200 L/min.Mainly for surface paint of structural members, Pressure ration: 32:1
  2)When there is welding backing, we require the groove direction being outward for the flange plates(opposite direction for web plates) and still falls on the direction in favor of welding on web plates. Please refer to illustration 2
3)Butt-welding on construction site:we require all the grooves should be bevelled on the upper rafter/column when it comes to bolt connection for web plates(see illustration 3). For the scenario of welding on web plates, please refer to the illustration 4.
3.3.2 Box column(groove on itself).See illustration 5
4. Welding groove form
4.1. Mark on form and size of welding joint groove:
Example: Shielded metal arch welding, complete joint penetration, butt welding, I shape groove, welding backing and single side weld would be marked MC-BI-BS1
4.2. For the mark of welding method and penetration type, please see the following chart 1.
Chart 1 Mark on welding method and penetration type  4.3. For the mark of single, double side welding and backing material type, please see the following chart 2
Chart 2 Single/double side welding and backing material type mark 4.4. Mark on each part size of groove, see chart 3.
Chart 3 Size mark on groove

Applicable Codes

LATEST INTERNATIONAL CODES COMPLIANCE
A. (GB50009-2012): Load code for the design of building structures
Loads on all buildings are applied in accordance with:
2012 edition of the Load code for the design of building structures

B. (MOHURD): Ministry of Housing and Urban-Rural Development of the People's Republic of  China

Manufacturing and Erection tolerances are applied as per:
GB50205-2001 edition Code for acceptance of construction quality of steel structures

C.(MOHURD): Ministry of Housing and Urban-Rural Development of the People's Republic of  China Hot rolled sections and built up sections are designed in accordance with:
GB50017-2017 Code for design of steel structure

D. CISA - China Iron & Steel Association - Latest Edition
Cold formed members are designed in accordance with:
GB50018-2002 Technical code of cold-formed thin wall steel structures


E. (MOHURD): Ministry of Housing and Urban-Rural Development of the People's Republic of  China

Welding is applied in accordance with:
JGJ81-2002 Technical specification for Welding of steel structure of building

F. Surface treatments are applied in accordance with:
GB/T 8923.1 Preparation of steel substrates before application of paints and related products-Visual assessment of surface cleanliness-Part 1: Rust grades and preparation grade of uncoated steel substrates and of steel substrates after overall removal of previous coatings

STRICT DEFLECTION CRITERIA
     Material Specifications

The material standards for which the building components have been designed as per specifications.

STANDARD MATERIAL SPECIFICATIONS