Load bearing modular formwork construction system for building high rise structures

Abstract

A modular hybrid construction system (100, Fig 1e) for building high-rise structures, in which the system comprises a plurality of Prefabricated Prefinished Volumetric Construction (PPVC) units (102,

Description

Field of Invention The invention relates to modular hybrid formwork building systems, in particular to high rise structures constructed using prefabricated building units. Background Traditional methods of modern building construction have primarily emphasized the cost and efficiency benefits of manufacturing construction components at dedicated plants or factories. One such approach involves creating building modules that are manufactured off-site and then transported to the construction location. This method, known as manufactured housing, offers several advantages compared to on-site construction techniques. For instance, manufacturing the modules indoors allows construction to continue throughout the year, regardless of weather conditions. Additionally, the use of assembly lines in manufactured housing results in quicker construction times, as it reduces the need for extensive on-site work. Nevertheless, there are challenges associated with manufacturing modules at a separate facility and transporting them to the construction site for final integration and finishing. The handling of modules can be arduous, time-consuming, and expensive, primarily due to their weight and the need for large cranes during lifting and this is not only expensive but difficult to source. Transportation of modular structures can also pose difficulties due to their size and weight, limiting the number of modules that can fit on a truck for delivery to the construction site. Furthermore, the lack of manufactured housing techniques that offer the necessary structural strength, joints and durability has resulted in the continued use of traditional on-site construction methods for high-rise and multi-storey buildings. In addition, all current buildings constructed using modular units together with load bearing walls where applicable, all of the load bearing walls require, on-site construction. These non-modular load walls are created by placing rods, beams, or a wire grid and pouring concrete on the construction site, making them non-reusable. Traditional modular units are typically designed as ‘box shaped units’ with a floor, ceiling, and external walls. Assembling a structure using these units leads to redundant floor, ceiling, columns and wall elements between the units, resulting in inefficiency and doubling of material used. Hence there exists a need for a new approach by utilizing prefabricated building units to overcome the aforementioned limitations associated with using manufactured housing structures or modules in the construction of high-rise and multi-story buildings. The needed construction system and method would offer several advantages, including accelerated construction time and cost savings, resulting in the rapid construction of high-quality multi-story buildings. Compared to conventional construction approaches, the proposed construction system and method would significantly reduce the construction timeline and allow for the creation of energy-efficient structures that operate with minimal maintenance expenses, but most importantly, it will allow most of the modular frame to be reused for the next modular frame. The invention aims to provide a modular and load bearing hybrid construction system and method for building high-rise structures that addresses these issues. Summary of Invention In an aspect of the invention, there is provided modular hybrid construction system (100) for constructing a high-rise building, the system (100) comprising: a plurality of Prefabricated Prefinished Volumetric Construction (PPVC) units (102), each having a self-supporting frame structure including a plurality of steel columns and beams, L-angle beams, and Parallel Flange Channel (PFC) beams to form a wall, a floor or a roof structure, or a part thereof, wherein the units (102) are configured horizontally or vertically according to a plan of the building, characterized in that: a unit (102) is interconnected horizontally with an adjacent unit by fastening two beams of the units using a plurality of steel bolts; and the wall of a unit is of a H-shaped contour, center of which has a reinforced steel bar, to which the L-angle beam of an immediately upper or lower unit can be fastened to prevent the units (102) from sliding on one another. Advantageously, the proposed system offers reduced construction time and cost savings, enabling the efficient construction of high-quality multi-story buildings that comply with major international building safety codes and standards. Additionally, the system ensures the structural stability and integrity of the individual units, effectively mitigating the risks of sliding or dislocation during the construction process. In one instance, the PPVC units are secured to at least one reinforced concrete beam or slab of the high-rise structure using the reinforced steel bars to provide structural support. Advantageously, this provides necessary structural support to the high-rise structure and ideal for areas of high seismic activity. In another embodiment, the wall structure of the modular construction system includes a plurality of H-Mold shaped frames configured to receive a plurality of prefabricated wall panels. Advantageously, this configuration allows to accommodate various types of prefabricated wall modules, such as Megawall and others, resulting in reduced construction time and cost, all of which is done in the manufacturing facility. Following the installation of the H-Mould , electrical and plumbing pipping is also installed before the formwork is finally fixed prior to delivery to site . In a yet another embodiment, the plurality of PPVC units of the modular hybrid construction system is prefabricated off-site using hot roll steel material and are configured to be transported and assembled at site in accordance with the pre-approved building plan. This feature offers the added benefit of facilitating rigorous quality checks and ensuring adherence to major international building safety codes and standards, thereby maintaining high construction standards throughout the process. In another embodiment, the reinforced steel bars are secured to at least one reinforced concrete beam or slab to provide structural support for the high-rise building. Brief Description of Drawings It will be convenient to further describe the present invention with respect to the accompanying drawings that illustrate possible arrangements of the invention. Other arrangements of the invention are possible, and consequently the particularity of the accompanying drawings is not to be understood as superseding the generality of the preceding description of the invention. Figures la-le depicts various stages of fabrication of the Prefabricated Prefinished Volumetric Construction (PPVC) unit according to a preferred embodiment of the present invention. The frame system can be fully welded or bolted depending on engineers’ requirements. Figure 2a-2c illustrates interconnection between adjacent PPVC units arranged in Figure le, according to an embodiment of the invention. Figure 3 illustrates vertical interconnection between adjacent PPVC units using reinforced steel bars, according to an embodiment of the invention. Figure 4 illustrates PFC Channel located below the RHS floor beams bolted to prevent sliding of the floors, according to an embodiment of the invention. The floor beam and the Ceiling Frame can be bolted where possible. Figure 5 illustrates the PPVC units secured to a reinforced concrete beam of the high-rise structure, according to an embodiment of the invention. Detailed Description A load bearing modular formwork construction system or hybrid construction system (100), also known as (MODFORM™), for building high rise structures for building high-rise structures using a number of same or various types of Prefabricated Prefinished Volumetric Construction (PPVC) units 102 is disclosed. Figures la-le illustrates various stages of fabrication of the PPVC units 102 according to a preferred embodiment of the present invention. Each of the PPVC units 102 comprises a structurally self-supporting frame structure 104 fabricated using a plurality of steel columns and beams, L-angle beams, and Parallel Flange Channel (PFC) beams to form a part of at least one wall, floor, and a roof structure of the PPVC unit 102. In one embodiment, the PPVC units 102 are prefabricated using hot roll steel material that complies to appropriate building codes and standards, such as BS EN 1090 or others depending of the country applicable codes. Further, the fabricated PPVC units 102 are inspected and certified offsite to the relevant standards prior to being transported to the site for assembling. Quality checks with tolerances of +0, -2mm is the current standards adopted for all high-rise construction in x-y-z direction. In one embodiment, the PPVC units 102 includes steel columns and beams, L-angle beams, and PFC beams which are welded or bolted together to form the self-supporting frame structure 104. In one or more instances, the sizes of steel columns and beams, L-angle beams, and PFC beams are selected depending on the respective fabrication or building construction standards. In one embodiment, the PFC 75 - 150 is used for the fabrication of ceiling structure, UB beams of various dimensions are used for the fabrication of columns supporting the frame structure and connected using L-angle of dimensions 75 X 50 X 5MM and RHS 100 X 50 X 4.5MM is used for the fabrication of floor frame. However, various other dimensions for the steel columns and beams, L-angle beams, and PFC beams can be selected based on the type of high-rise structure and the selected construction or fabrication standards. Once the frame structure 104 of the PPVC units 102 are tested and approved, according to one embodiment, structural decking is welded on to the floor frames as shown in Figure lb with multiple starter bars welded at 600mm centers for bond shear with the concrete during the construction of the high-rise structure. Further, appropriate cutouts are made in the frame structure 104 for plumbing, electrical and other provisions according to the approved layout of the high-rise building structure. In one instance, the frame structure 104 of the plurality of PPVC units 102 is prefabricated off-site using hot roll steel material and are configured to be transported and assembled at site in accordance with the pre-approved building plan. In yet another embodiment, the frame structure 104 of the plurality of PPVC units 102 including the flooring and walls are fabricated offsite or at a factory and are transported to the site for further inspection and installation of each PPVC unit 102. In an embodiment, as shown in Figure 1c, appropriate framework or H-shaped framework or moulds 106 are installed to the hot roll steel frame by welding. The H-moulds 106 on the wall frame is configured to receive prefabricated modular wall formwork panels such as, but not limited to, MegaWall type wall panels. This further speed up the fabrication, transportation, and construction of the high-rise structure as no further fabrication and testing needs to be performed at the site. Further, the H-mould 106 acts both as steel reinforcement and as a structural support to the frame structure. In one instance, once the H-moulds 106 for the prefabricated wall panels such as the MegaWall formwork is secured in place, the electrical conduits and plumbing pipping is installed on the walls, floors, and roof structures. In one instance, the H-moulds 106 for the prefabricated wall panels such as the Mega Wall formwork is then installed on one side of the PPVC unit 102, steel reinforcing bars are provided for structural support before the walls are fully closed up ready for inspection, site transportation and construction of the high-rise structure by stacking the PPVC units 102 horizontally and vertically on top of each other as shown by Figures Ic-ld. In one embodiment, the adjacent PPVC units 102 arranged as shown in Figure le are interconnected horizontally using steel plates 108 attached to each steel column as shown in Figure 2. In one embodiment, each column of the PPVC unit 102 is attached with a 9mm mild steel plate using welding on inside of a flange of the U beam column section. The steel plates 108 helps to interconnect columns of the adjacent PPVC units 102 by bolting and helps to the ease the installation of each of the PPVC unit 102 in the horizontal direction based on the pre-approved building layout. Further, once the concreting of the wall structures is completed the PPVC units 102 are held by a composite action of the slab and the shear wall without lateral movement or sliding during the construction of the high-rise structure. Further, as shown in Figure 3, the PPVC units 102 of the high-rise structure are interconnected vertically using a reinforced steel bar 110 of size 16mm provided at a center of each beam as shown in Figure 3b. This helps to provide structural support to the high-rise building structure and prevents the sliding of the PPVC units 102 while concreting. In one embodiment, once all the second-floor PPVC units 102 have been installed, temporary L-angle type LM-LR beam 112 are installed. In one instance, the L-angle beam 112 is provided between each pair of C-section beams on the floor and / or roof structure to prevent sliding of the PPVC units 102 while concreting as shown in Figure 4. Once the fabrication of the entire floor is completed then the concrete floor and shear walls are casted. In another instance, the PPVC units 102 are secured to at least one reinforced concrete beam of the high-rise structure using the reinforced steel bars to provide structural support as shown in as shown in Figure 5. The fabrication process is repeated for the next floor PPVC units 102. In one embodiment, the steel plates 108 used for the fabrication are different from the ones that is used on the ground floor and the steel plate 108 are either bolted or simply allowed to make an interlocking connection with the adjacent PPVC unit 102. The following paragraphs describe a method for constructing a typical high-rise building using the proposed PPVC units (102), according to an embodiment of the invention. Before commencing with the installation of PPVC units 102, the project manager, COW, or contractor representative ensures that the site is prepared for the approved erector to secure their works. Site preparation typically includes aligning and leveling all concrete beams to the correct height for the PPVC units 102, and completing any necessary corrective works to avoid any impedance. Once the above step is completed, all 16mm reinforced steel bars on the Ist-floor roof beam are installed at the center of the beam and firmly secured to the concrete beam. Furthermore, all PPVC units 102 that are ready for installation are checked to ensure their dimensions are in agreement with site tolerances. Proper scaffolding / boom lifts are provided for climbing as and when necessary for inspection work. Additionally, appropriate craneage with the proper lifting capacity is ensured for all lifting of the PPVC units 102, and qualified operators make sure the units are placed correctly with minimum or no damage. The further erection / installation procedure for constructing the high-rise building using the PPVC Units 102 follows the stages described in the following description: Step 1. On arrival of the PPVC units 102 at the site, use appropriate lifting equipment to unload the units 102 onto temporary storage frames provided by others. Assemble all completed PPVC units 102 closest to the location of the building, along with other sections and ancillary components. All electrical, hydraulic piping, and other services are to be installed prior to the installation of the PPVC units 102. Step 2. The PPVC Units 102 are inspected prior to installation. Once this has been done, the canvas covers are removed. Install the guide plates as per the drawing and check the levels to ensure that all connections will be in order for the first PPVC unit 102. It is advisable not to install all of the guide plates around the PPVC units, but instead, install the plates that surround the first few PPVC units in case of any adjustments. Once the dimensions are checked and everything is in order, prepare steel packers and level them on the beam, ready for the installation of the PPVC units. Note that the ground floor and 1st floor construction method will not be using an Eco-Build Mega wall PPVC system or any other prefabricated formwork for the walls; instead, a precast column-beam system carried out by others will be undertaken. Step 3. Once the above steps are completed, the PPVC unit 102 is lifted using the lifting lugs supplied onto the 1 st-floor roof beam, following the markings as per the Master Plan Drawing. After laying the first PPVC unit on the relevant plates, place the next PPVC unit 102 until one entire apartment is complexed and level, as shown in Figure 5. In the next step, step 4, temporary supports are provided to stabilize the PPVC units, if necessary. Steps 2, 3, and 4 are repeated for the 2nd PPVC Unit 102. Once all the second-floor units have been installed, the upper and lower modules are bolted to hold the PPVC units 102 in place during concreting and prevent sliding. After completing the entire floor, the concrete floor and shear walls are cast. In some instances, due to the large span, the modular formwork or the Megadek BP formwork needs to be temporarily supported at double span for at least 3 working days. Figures 2-4 illustrate the above-mentioned steps and the further procedure for casting walls. The above-mentioned steps are repeated for the 3rd floor PPVC units 102. In some instances, the plates used in the assembly of 3rd floor PPVC units 102 are different from those used on the ground floor. In one embodiment, during the assembling of the 3rd floor PPVC units 102, the plates are not bolted; they are just placed for interlocking purposes only. Steps 2, 3, and 4 are repeated until all the PPVC units 102 have been installed. Once this is completed, the floor and walls will be cast to create a shear wall system as shown in Figure 3. In the next step, once all the bolts are installed, all dimensions are rechecked to ensure that they are within the site tolerance and that all PPVC units 102 are properly interlocked with each other. Then, in some instances, external structures such as the balcony are installed as per the drawing, considering the position of the Steel Square Hollow Section posts supporting the balcony and the trusses if applicable. After completing all the PPVC units 102, the installation of steel trusses and metal roofing is carried out. In some instances, where the intermediate supports do not meet, shims are placed to distribute the load, and braces are left in place to improve lateral stability. In certain embodiments, upon completion of the installation as stated in the above steps, the following internal fit-out works are carried out. Fire protection boards are installed where necessary before installing all other interior items, especially the ceiling where all services run into the apartments. Main Distribution Electrical cabling and water pipes are typically located along the corridors and reach each floor via the Mechanical and Electrical risers. Windows and doors are also installed and finished to ensure that the apartments are water-tight before the finishes are installed. In a typical unit, the internal walls are provided with a 5mm skim coating, and external walls with a 12mm render coating. Floor finishes are also installed using appropriate waterproofing glue or coating and grout. Further, installation and furnishing works are performed as deemed necessary. Typically, the furniture is completed at the factory (flat pack) and positioned inside the units according to the interior layout. It will be appreciated by persons skilled in the art that the present building fabrication system may also include additional modifications which do not affect the overall construction of the high-rise structure.

Claims

1. A modular hybrid construction system (100) for constructing a high-rise building, the system (100) comprising:a plurality of Prefabricated Prefinished Volumetric Construction (PPVC) units (102), each having a self-supporting frame structure including a plurality of steel columns and beams, L-angle beams, and Parallel Flange Channel (PFC) beams to form a wall, a floor or a roof structure, or a part thereof, wherein the units (102) are configured horizontally or vertically according to a plan of the building, characterized in that:a unit (102) is interconnected horizontally with an adjacent unit by fastening two beams of the units using a plurality of steel bolts; andthe wall of a unit is of a H-shaped contour, center of which has a reinforced steel bar, to which the L-angle beam of an immediately upper or lower unit can be fastened to prevent the units (102) from sliding on one another.

2. The modular hybrid construction system (100) of claim 1 wherein the PPVC units are secured to at least one reinforced concrete beam or slab of the high-rise structure using the reinforced steel bars to provide structural and support.

3. The modular hybrid construction system (100) of claim 1 or 2 wherein the steel plate is attached to an inside of a flange of the steel column using welding.

4. The modular hybrid construction system (100) of any one of the preceding claims wherein the wall structure includes a plurality of H-Mold shaped frames configured to receive a plurality of prefabricated H-Frame wall panels.

5. The modular hybrid construction system (100) of any one of the preceding claims wherein the plurality of PPVC units is prefabricated off-site using hot roll steelmaterial and are configured to be transported and assembled at site in accordance with the pre-approved building plan.

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