Introduction for Low Price Construction Material Steel Structure Showroom Building Metal Mall Design
Aruba exhibition hall project is a renewal project of Aruba stadium customers, with a building area of 1585 square meters. The exhibition hall is a two-story frame structure, and the warehouse is a portal steel frame structure. Some walls of the exhibition hall are made of glass curtain wall and others. The storehouse is made of cement foam board, and the roof is a polyurethane composite board.
Project location: Aruba
Area: 1585 square meters
Eaves height: 8.4m
Number of floors: 2
Wind speed: 148km / h
Steel consumption: 92t
Low Price Construction Material Steel Structure Workshop Building Metal Factory Shed Design
Q235B,Q345B galvanized or painted steel
H-section steel column and steel beam
C/ Z- section steel purlin
Roof and wall
a) Color-coated corrugated steel sheet,
a)Rolling up door,
PVC /Steel or Aluminum Alloy frame window
Round PVC pipe
All kinds of industrial workshop, warehouse, poultry shed, supermarket, hangar, etc
Roof with a single layer of galvanized steel plate sea blue crown Island, its structure and technical requirements are as follows:
1.V820 type 0.50mm thick galvanized roof panel (sea blue) crown Island
2.75mm thick glass wool with aluminum foil
3.200 * 200 coated steel mesh
4.Q235B C-type steel roof purlin
5.Q345B steel beam
1.YX-840 plate type 0.40mm thick galvanized wall panel white gray crown Island
2.Q235B C steel wall purlins
3.Q345B steel column
1. Shot blasting, rust level Sa2.5
2. In the gray anti-corrosion primer two, each 30 um
1. Roof panel - sea blue
2. Wall panel - white gray
3. Steel components - medium gray
Prefab House refers to a building where parts and components produced in a factory are assembled and connected at the construction site. Steel structure prefabricated buildings refer to steel structure components produced in factories and assembled and connected at the construction site.
Different countries have different understandings and practices of the housing system, but Prefab House generally refers to the main project of the house. Different residential products are formed due to the selection of different structural materials, structural types and construction methods, and constitute a number of corresponding residential products ranging from design to The complete technology of construction. The steel structure residential building system uses the steel structure form as the basis for the classification of the building system and becomes a branch of the building system.
The material of Prefab House has good homogeneity and isotropy, which is an ideal elastic body, which is most in line with the basic assumptions of general engineering mechanics; the material has good plasticity and toughness, can have large deformations, and can well withstand dynamic loads; construction period is short ; It has a high degree of industrialization and can be used for specialized production with a high degree of mechanization; it has high processing accuracy, high efficiency, and good airtightness, so it can be used to build gas tanks, oil tanks, and transformers.
In the future, the steel structure of Prefab House should study high-strength steel to greatly increase its yield point strength; in addition, new types of steel should be rolled, such as H-shaped steel (also known as wide flange steel), T-shaped steel and profiled steel plates, etc. The needs of large-span structures and super high-rise buildings.
(1) Light weight and high strength. Due to the use of steel as the load-bearing structure and new building materials as the enclosure structure, Prefab House generally uses steel structure to build residences that weigh about one-half of the weight of reinforced concrete residences, which reduces the weight of the house and reduces the cost of basic engineering. Since the building area occupied by the vertical force-bearing member is relatively small, the use area of the house can be increased. At the same time, because the steel structure residence adopts a large bay and large depth column network, it provides residents with a large space that can be flexibly separated, which can meet the different needs of users.
(2) The degree of industrialization is high and meets the requirements of industrialization. Most of the structural components of Prefab House are made in factories, which are easy to install and suitable for mass production. This has changed the traditional way of housing construction and realized the transformation from "building houses" to "manufacturing houses". Promoted the transformation of the housing industry from extensive to intensive, and at the same time promoted the development of productivity.
Qingdao Xinguangzheng Steel Structure Co., Ltd. has worked on the production of Prefab Houses for several years. You can find the best Prefab House in this company.
Qingdao Xinguangzheng Steel Structure Group completed Qingdao Haier Yungu Supporting School Project on August 31, 2022.
Ⅰ. Steel column installation for steel structure construction
1. Installation sequence of steel column:
① Foundation setting out → ② binding → ③ hoisting → ④ correction → ⑤ final fixation
2. Installation method of steel column:
(1) Setting out:
A. Elevation control:
In this structural steel construction project, iron parts and "middle bars" are controlled according to the depth of concrete cup mouth, the elevation of steel column bottom and the embedded elevation in the center of the bottom of the cup mouth during the construction of concrete foundation (φ30 steel bars), the elevation of top surface of "middle reinforcement" is based on the elevation of steel column bottom, and the elevation error of iron parts is controlled in ± Within 1mm.
To ensure the steel column is embedded in the foundation accurately and firmly φ On the 30 "middle reinforcement", weld a steel plate with thickness of 20 at the bottom of H-shaped steel column, as shown in the figure below.
When installing structural steel column, clean the foundation cup mouth first, and check the embedded elevation control "middle reinforcement" in the foundation（φ The actual height of 30 steel bars) is not necessary because the elevation embedded in the foundation construction has been controlled precisely, and no additional iron pad is needed. The method is simple, fast and efficient for the treatment of steel column feet. The construction is fast and the force is reasonable. When the column is lifted, it can be adjusted freely in several directions when the elevation is unchanged.
B. Before installation, the vertical and horizontal axis reference lines of the foundation plane shall be placed on the top of the cup mouth by woodworking ink bucket as the installation and positioning line of steel column.
(2) Column binding and hoisting:
A. after the steel column enters the site, the steel column shall be arranged according to the position of the lifting plan, and the model and number shall be checked to see if they are correct. The plane position of steel column after entering the site is shown in the following figure.
B. Before the column is lifted, a horizontal line shall be drawn with red oil paint 2300mm upward from the bottom of the column, so as to recheck the plane elevation datum before and after the installation and fixation.
C. the column installation belongs to vertical hoisting. In order to keep the suspended column drooping and facilitate the positioning, the binding point is determined at the lower part of the bracket. In order to prevent the sharp edges and corners of the column edge from damaging the lifting rope during hoisting, the rubber belt of the old car is used to separate and cover the edge and corner lifting rope. Pay attention to binding firmly and easy to remove.
D. temporary steel ladder and high-strength bolt installation fixture of working platform shall be bound on the steel column.
E. in order to avoid the free swing of the suspended column, hemp rope should be used to tie the upper part of the column bottom as a restraint rope and adjust the direction.
F. according to the site conditions, the rotation method is adopted for hoisting
After the preparations before hoisting are ready, the trial hoisting shall be carried out first. When the height of the steel column is 200 mm above the ground, the hoisting shall be stopped to check whether the rigging is firm and whether the crane is stable. After confirming that there is no problem, the crane can be directed to slowly lift, rotate to the top of the cup mouth, and then slowly descend. When the distance between the bottom of the column and the design position is 40-100 mm, adjust the two datum lines of the column body and the foundation to reach the accurate position, direct the crane to descend to the position, and temporarily fix the column with steel wedge (or wood wedge) and wind rope to remove the hook.
• Key points of rotation method:
The method of lifting the column by rotating the column around the column base is called rotation method, as shown in figure a below. When the column is hoisted by rotation method, in order to improve the hoisting efficiency, when the steel column enters the site, the binding point of the column, the center of the column base and the center of the cup foundation should be placed on the arc with the crane stop point as the center and the distance from the stop point to the binding point (i.e. the turning radius of the column), as shown in Figure B below.
The steel column hoisting is shown in the figure below:
(3) Preliminary correction of column:
The column should be corrected on the side with large deviation first, and then on the side with small deviation.
A. The correction of column generally includes plane position, elevation and perpendicularity.
B. When the steel column is hoisted in place, it is one-time alignment, and generally it does not need plane re correction. For the elevation of the column, it has been used before hoisting φ The embedded "middle reinforcement" can accurately control the elevation. Generally, it only needs to be checked, and it does not need to be corrected. Therefore, the steel column correction is mainly to correct the verticality and recheck the elevation.
C. In this project, the perpendicularity of the column is observed, and two theodolites are used for measurement and correction.
• First, place the theodolite on one side of the column, align the longitudinal center wire with the baseline of the column base, and then fix the screws of the horizontal plate.
• Measure the center line of the column and observe from bottom to top. If the vertical center line is aligned, that is, the column is vertical. If it is not aligned, the column shall be adjusted until it is aligned with the longitudinal center line of theodolite.
• Measure the horizontal line in the same way so that the center line of the other side of the column is perpendicular to the horizontal axis of the baseline. After the column is accurately positioned, the column can be fixed.
• Verticality correction of steel column: distance adjusting screw rod and steel wedge are used. Due to the small contact surface of the long side of the column, the base plate is set during the construction. The details are as follows.
The manufacturing dimension of steel wedge is shown in the figure below:
(4) Final alignment and fixation of steel columns:
After the steel column is hoisted in place, the column correction mainly involves the adjustment of elevation and the correction of verticality; The correction method can use tools such as wind rope, Jack, crowbar and steel wedge (or wooden wedge) to apply vertical force and lateral force of pulling, jacking, supporting and prying to the steel column.
Adjust the verticality, positioning axis and elevation of the column. After confirming the correctness, the gap between the steel column and the foundation cup mouth shall be poured with C40 fine stone concrete. The expansive high strength grouting material is preferred.
Ⅱ Protection of site components:
1) The unloading of components shall be careful to prevent damage and prevent collision and extrusion between members.
2) The members shall be stacked in order at the designated site, and the number of layers stacked by steel beams shall not exceed 3 layers to prevent the members from squeezing and deformation.
3) Before hoisting, oil, sediment and dust on the surface of the components shall be cleaned.
Ⅲ The placement of components and the requirements for the site
1) When unloading, the components are unloaded directly near the installation position and within the radius of rotation of the crane. Mark the number clearly with a clear color pen to facilitate lifting.
2) The components are placed in order in the site, and a certain gap is reserved between adjacent components to facilitate binding.
3) The site shall be solid and flat, and the components shall not be polluted due to rain and snow, and the vehicle with 30 ton level can be walked.
Ⅳ Steel structure building installation
Preparation before hoisting of steel column:
Before hoisting the steel column, the cable wind rope shall be tied to the column body. The lifting point shall be at the bracket position, and the double wire rope shall be set up and down, and the snap ring can be checked to be qualified before entering the next work. Before hoisting the steel column, the positioning axis, foundation axis and elevation, cup opening size and the height of the bottom standard of the steel column must be inspected and handed over and accepted. The number, outline dimension, screw hole position and diameter of the steel column shall be comprehensively reviewed. After confirming that it meets the requirements of design drawings, draw out the installation center line and the lower end elevation line of the steel column.
Ⅴ Steel column hoisting
(1) installation method of steel column
Before lifting the steel column, the wooden board shall be fixed at the column foot to prevent damage to the column foot and other structures.
Special hoisting steel wire rope is used for steel column binding. Wood or rubber sheet shall be used to prevent damage to the steel column.
The steel column is installed by a 25t truck crane. When the steel column is lifted, the crane shall hook and rotate the arm while lifting the steel column to make the steel column vertical away from the ground.
(2) positioning adjustment and temporary fixation
When the steel column is lifted to 200mm above the base cup mouth, it will be stable, and it will fall slowly at the base cup mouth. Avoid hitting the concrete edge of the foundation cup mouth during falling. After implementation, use special angle ruler to check, adjust the steel column to make its positioning line coincide with the foundation positioning axis. Three people are required to operate the adjustment, one person moves the steel column, one person helps to stabilize and the other person conducts the test. The positioning error is controlled within 2mm.
(3) when adjusting the elevation of the steel column, place the pad iron at the bottom of the cup foundation, use the level to super level the bottom plate elevation of the steel column as the top elevation of the pad iron, so that the elevation after the steel column is in place can meet the design elevation requirements, mark the elevation datum point on the column body, and then use the level to measure the installation elevation after it is installed in place.
(4) the verticality of the steel column shall be preliminary adjusted by the level ruler. Then two theodolites are used to observe from both sides of the column at the same time, and the adjustment is carried out by relying on the cable wind rope. As shown in the figure below:
Diagram of verticality adjustment of steel column
(5) after the adjustment, use eight iron wedges to position the gap between the bottom of the steel column and the base of the cup mouth, and then spot weld the column to make it stable.
Ⅵ Steel beam installation
Steel beams must be stacked in order on site for this steel work in construction. Sleepers must be placed in the middle of each layer of steel beams. Two lifting points for steel beam hoisting are selected on both sides of the center of gravity of the steel beam. The two lifting points should be 800mm away from the support and the middle of the span, and the distance between the two lifting points should be increased according to the length of the steel beam.
To ensure safety and prevent the sharp edge of the steel beam from cutting the steel wire rope, the steel wire rope shall be protected, the angle of the sling shall not be less than 450, and the steel beam shall be directly tied and rolled with the steel wire rope or lifted with a special fixture.
Before hoisting the steel beam, install the safety rope on the steel beam. When hoisting, hang two sliding ropes at both ends of the steel beam. Two people pull two sliding ropes respectively. The hoisting speed of the steel beam must be slow. In order to ensure safety, personnel should not stand directly under the beam. The cloth bags specially used for placing high-strength bolts are put on both ends of the steel beam. When the steel beam is hoisted above the position, the steel beam is put in place. The falling speed of the steel beam is controlled at 3m / min. two installers are arranged at both ends of the steel column head to prepare for the installation of the steel beam. When the steel beam is close to the in place position, two installers should hold the upper flange of the steel beam with their hands respectively, drag the steel beam to the in place position, and prepare to install the high-strength bolts.
Ⅶ Installation of retaining structure and support corner brace
1) Installation of roof purlin: when the main structural steel forms a frame section, the roof purlin is hoisted to the main beam of the roof with a crane and installed manually. The purlin can also be manually pulled onto the roof with a white synthetic rope for installation. After the installation of purlin, the purlin support is installed in time.
2) Wall purlin installation: when the main structure forms a frame section, the construction personnel stand on the scaffold platform and pull the wall purlin to the installation position with white comprehensive rope.
3) Corner brace installation: after the main body is welded, the corner brace is connected.
Ⅷ Measurement and correction of steel column
Verticality correction of steel column
When the steel column is installed and corrected, two theodolites are set up on the control line with 90 degree translation of 1 meter each other, and the theodolite operators observe the small steel ruler on the top of the column, measure the deviation of the steel column and direct the correction.
A. Control the verticality of the steel column between the first hoisting joints.
B. Steel column calibration is divided into four steps:
initial calibration during initial tightening; Re-calibration before final tightening; Tracking and monitoring during welding process; Final result measurement after welding.
The perpendicularity can be roughly controlled with a long level before the initial tightening, and it can be accurately corrected after the frame is formed. After welding, retest shall be carried out, and the measurement results shall be compared with those at final tightening, so as to be the basis for the next construction.
C. Verticality measurement method of C steel column
Initial correction: the perpendicularity of the steel column is preliminary adjusted with a level ruler.
Accurate correction of steel column perpendicularity: one column grid is used as an installation section for the hoisting of the main frame until the hoisting of three continuous complete sections is completed
After the whole is formed, the measurement correction can be inserted. Two theodolites are used to observe from both sides of the column at the same time, and the wind rope is used for correction and adjustment.
Ⅸ Steel structure survey
2) Elevation control of steel column
Based on the elevation reference point of the plane layer where the steel column is located, the deviation value of the horizontal elevation of the steel column is measured with the level gauge and the correction is directed.
3) Steel beam measurement
After the steel column is hoisted and corrected, the +1.00m control point shall be measured to each steel column according to the site level as the basis for vertical transfer of elevation and the elevation of beam installation; Pop up the center line of the steel beam on the surface of the steel beam.
The control axis is measured to the column body to control the beam position offset; The accuracy of beam elevation is controlled according to the control point of column elevation. Set up theodolite on the floor platform, and then look at the cross angle to the axis of the corresponding beam. Aim at the center line of the upper surface of the beam to the other end with theodolite to see if the number coincides with the axis of the beam.
Calculation of survey and lofting data
In this project, the computer automatic query method is used to calculate the survey and lofting data. The specific steps are as follows:
1) The establishment of data model
Firstly, according to the design coordinates and the dimension relationship of each building in the design drawing, the building, building axis, control line to be lofted and so on are drawn in AutoCAD according to the proportion, and the data model is established.
2) Survey and lofting data query
After drawing the survey loft data model, the survey loft data such as the angle and distance between the known basis (axis control pile, lofted axis, etc.) and the control line to be lofted are queried by using the command of dist of AutoCAD.
3) Advantages of computer automatic query
The method of computer automatic query is used to obtain the required measurement and positioning data. It is not only convenient to calculate, but also has high precision. The distance precision can be set to 0.1mm, 0.01mm, and the angle precision to 0.0 ", 0.00" or higher according to the actual situation.
Ⅹ Construction of high strength bolt
1. Preparation before installation
1) Test and inspection of high strength bolt
Anti slip coefficient test
The project adopts class 10.9 large hexagon high-strength bolts. The anti slip coefficient test of high-strength bolts shall be conducted by taking the most representative thickness of the plate in the project for test, and three groups shall be made.
The size of the specimen plate is as follows:
Axial force test
Randomly select the bolts to be installed at the construction site, and 8 sets of bolt pairs are selected for re inspection in each batch.
2) Transportation and storage of high strength bolts
The form, size and technical conditions of high-strength bolt connecting pair shall be manufactured and supplied by the manufacturer according to batch, with factory certificate and high-strength bolt connection pair, which shall conform to the provisions of national standards gb1228-1231-84 and gb3632-3633-83. High strength bolts with large hexagon for steel structure
The connecting pair consists of a bolt, a nut and two washers. The combination of use shall meet the national standards, and the high-strength bolt connection pair shall be supplied with storage and transportation in the same batch.
The high-strength bolt connecting pair shall be installed and placed lightly during loading, unloading, transportation and storage to prevent the packing box from being damaged or damaged.
Storage of high strength bolt warehouse
1. the high-strength bolt connection pair shall be cleaned according to the specification, batch number and supply date of the packing box, and shall be kept in the indoor warehouse, and the accumulation shall not be higher than 3 layers. The indoor moisture-proof, long-term dry, rust and dirt contamination shall be prevented, and torque coefficient shall be prevented from changing. The bottom layer shall be more than 300mm above the ground level.
2. when installing on site, the quantity of high-strength bolts required on the day shall be issued. The rest should be kept properly. Do not put it in disorder, damage the thread, and be contaminated with dirt.
3. before using the long-term storage high-strength bolt connection pair, a comprehensive quality inspection shall be conducted again. If any abnormal phenomenon is found after unpacking, the inspection standard shall be conducted according to the relevant provisions of national standards gb1228-1231-84 and gb3632-3633-83. It can be used after being qualified.
3) Construction management of high strength bolts
1. Construction Manager
When carrying out the construction of this high-strength bolt, the high-strength bolt manager shall be determined first to be responsible for the project management, quality management and guidance of the construction personnel.
2. weather management (climate conditions)
In principle, no operation shall be carried out during rainfall and snowfall. If rain or snow fall occurs during operation, the speed shall be accelerated to lock the unfinished ones
3. friction surface management
Before tightening, the friction surface shall be inspected first. If there are any attachments to reduce bearing capacity of friction surface, such as rust, oil, paint and residue, metal brush, sandpaper and oxygen acetylene flame shall be used for removal.
4) Construction of high strength bolts
1. final tightening of temporary bolts
Before inserting high-strength bolts, temporary bolts shall be used to tighten the connection tightly, if the materials of the connection parts are bent or warped, they shall be corrected.
If the difference of holes is within 2mm, it can be corrected by cutter.
If the difference of holes exceeds 2mm, reasonable treatment methods such as replacement of panel shall be adopted based on consultation with management personnel, and gas cutting and reaming are not allowed.
2. high strength bolt insertion
The nut and gasket of high-strength bolt shall pay attention to the installation direction, and install according to the following figure.
When inserting bolts, pay attention not to attach rust, dust, oil, etc. to the bolts. In addition, do not force into the bolt hole during construction to avoid damaging the thread.
3. initial tightening
After the temporary fixing bolts are locked, confirm the compactness of the components.
After initial tightening, mark with white marker through bolt nut, gasket and component.
When using the inspection wrench, although the torque value can be confirmed by the contact sound, it is easy to over tighten if the mechanism continues to apply force, so it should be noted.
4) Final tightening
After initial tightening, use special fastening wrench to lock until the neck is broken.
In principle, the bolts inserted on the same day shall be screwed out on the same day.
The full name of MDC is"MONDU DA CASA (home world)", which is constructed by Qingdao Xinguang Zheng Steel Structure Co., Ltd. This is a comprehensive shopping center centering on the theme of "happy home". This theme is the same as the enterprise mission of "benefiting the society, achieving employees and making customers happier". In addition to "home world", she has another interpretation of "modern decoration Center".
MDC is located in KIKUXI section of Luanda expressway, surrounded by Angola national stadium, high-end residential villa area, Brazil nursery garden, and Luanda commercial pedestrian street under planning, with superior geographical environment and convenient transportation.
"MDC home world" shopping center covers an area of about 30000 square meters. Relying on the global procurement network, it has gathered kipor generator 4S shop, furniture store, building materials store, home furnishing store and home appliance store. The categories include building materials pipe fittings, wood, floor tiles, paint and coating, decorative lamps, kitchen and bathroom equipment, hardware tools, electrical and electrical materials, gardening supplies, cloth furniture, home appliances, etc., and also auxiliary It is one of the most comprehensive "one-stop purchasing" centers for home furnishings in Luanda with public service facilities such as business office, catering, leisure and entertainment, bank, etc.
Introduction of Zhongjie era Steel Structure Frame Overpass Project
Zhongjie Times Square overpass project is the first Cross Street overpass project in Pingdu. The whole project is composed of three overpasses. The length of the straight overpass on the east side is 56.3 meters and the width is 5 meters. The length of the straight overpass on the west side is 49 meters and the width is 5 meters. The diameter of the main bridge surface of the central circular overpass is 56 meters. The narrowest part is 6.5 meters and the maximum width is 12 meters. The construction of the overpass on Hongqi Road can avoid the interference of people and vehicles To improve the road capacity, and effectively solve the problem of efficiency and safety of a large number of people crossing the street.
After completion, it will become the most characteristic commercial block with urban flavor in the main urban area of Pingdu City, as well as the landscape landmark and cultural landmark of Pingdu.
A lot of work is needed to promote and improve the design specifications and construction technical standards of different types of structures, and to develop new types of lightweight insulation wall materials and the supporting issues of residential components. At the same time, it is necessary to widely publicize the advantages of the development of Residential steel building, so that more developers, designers and users can understand and understand steel structure housing.
What are the main forms of Residential steel building?
What are the structural characteristics of these Residential steel buildings?
What should I pay attention to when using Residential steel building?
Judging from the Residential steel building that has been built, the king has:
1) Thin-walled steel composite wall panel form;
2) Pure frame form;
3) Frame support form;
4) Form of steel-concrete combination;
5) Steel frame-concrete seismic wall form and so on.
The structural forms of Residential steel building have their own characteristics. Among them, the thin-walled steel composite wall panel is particularly suitable for finalized products. The Residential steel building system evolved from the wall panel structure, that is, the thin-walled steel column members are arranged at a distance of about 600mm. The vertical load-bearing structure and section steel have a support system to resist horizontal forces. The floor slab is arranged as a multi-rib support structure according to the position of the vertical section steel. Because the upper structure is a wall-like structure, the foundation is set as a strip foundation according to the force. The foundation requirements are not high.
The thin-walled steel composite wallboard residence is affected by the dense structure, and there are certain restrictions on the size of the partitions, door, door and window openings, and pick-out components.
The latter several forms of Residential steel building can meet the design requirements of multi-story residential buildings, but there is a common problem from the perspective of use, that is, the impact of the prominent beams and columns on the interior look and feel of the residence.
Compared with other buildings, Residential steel building has its particularity. Offices and workshops can use a relatively fixed column network, and the storey height is also higher. The space occupied by the beams and columns is suitable for people. The rules of the column network are conducive to the beams. Layout. On the contrary, the residence is a product with many changes. According to the requirements of the building, a regular column network is rarely arranged. The interior space of the house is relatively small and changes a lot, which is not conducive to the layout of the steel frame.
After seeing this and learning so much information about residential steel structures, I believe you must also want to order a Residential steel building. Qingdao Xinguangzheng Steel Structure Co., Ltd. can provide the best Residential steel building you need. At the same time, their after-sales service is also very considerate.
Production introduction of Steel Structure AUDI Showroom and Workshop
Project Name: Audi Showroom and Workshop
Project Area: 4600 m2
Project address: Montevideo Uruguay
1. Showroom: Roof beam is truss structure, column is Box steel
2. Workshop: Roof beam is H section steel, column is H steel.
3. Wall Panel: Horizontal-Assembling PU Sandwich Panel
4. Roof Panel: EPS Sandwich Panel