LIGHTWEIGHT CONCRETE WALL FOR MODULAR INTEGRATED CONSTRUCTION (MIC) SYSTEM

Description

FIELD OF THE INVENTION

The present invention relates to modular integrated construction. The invention relates to construction from prefabricated modules, such as Modular Integrated Construction (MIC)/Prefabricated Prefinished Volumetric Construction (PPVC) and, more particularly, to interconnection between wall panels and beams within a module.

BACKGROUND OF THE INVENTION

High-rise buildings are typically built one level at a time by traditional construction methods, which follow a linear construction sequence on site. Substantial casting of concrete occurs on-site which is subject to external factors such as weather conditions, available manpower, and availability of knowledgeable workers. In addition, the internal finishing of each floor, for example electrical and hydraulic systems, can only be performed after construction of the building. These interior finishes are difficult to complete in the on-site environment.

Modular integrated construction (MiC) is an innovative construction technique that uses free-standing volumetric modules fitted with internal finishes, fittings and fixtures. Typically, the prefabricated modules represent a unit of a building, such as a flat, apartment, office, or a portion thereof, optionally formed complete with plumbing fixtures, electrical wiring, built-in cabinets, etc. The prefabricated modules may include up to four vertical walls and a ceiling and floor; alternatively, they may have fewer than four walls and only a ceiling or floor with the third and/or fourth wall and either ceiling or floor being provided by an adjacent module These modules are prefabricated off-site in a factory prior to transportation to a construction site where they are assembled into multi-storey buildings. By using MiC construction techniques, buildings can be assembled in a shorter period of time with better quality control, fewer workers, and a reduction in construction waste. Additionally, MiC results in reduced building costs and a safer work environment.

Concrete MiC has been adopted in an increasing number of residential building projects and is becoming the trend for high-rise private residential buildings because of the similar touch and feel as conventional reinforced concrete building construction and its merits of reduced inspection and maintenance costs after completion of the buildings.

However, the heavy weight of conventional concrete modules in Modular Integrated Construction (MiC) and the load capacity limitations of currently used tower cranes restrict the dimensions of building modules. Furthermore, in current concrete MiC practices, lightweight concrete is rarely used for shear wall structures. This is primarily because the properties of lightweight concrete often fail to meet the structural requirements for shear walls, which need to provide rigid resistance against vertical and lateral forces and effectively transfer loads to the building's foundation. Consequently, the use of conventional concrete for shear walls results in inflexible usage spaces and architectural layouts, as these heavy structural elements cannot be easily modified or removed without compromising the building's integrity.

Another challenge with concrete MiC is the extensive wet trade work required on-site due to current connection joint designs. These designs typically involve either lapping reinforcement bars and pouring in-situ concrete between modules, or using semi-precast slabs and walls with protruding reinforcement bars that require in-situ concrete to be poured into designated connection zones or cavities. Another problem with concrete MiC is the tedious and large wet trade work on site due to the existing connection joint design by lapping rebars and on-site concrete between modules, or by semi-precast slab, semi wall lapping rebars and on-site concrete to pockets.

Consequently, a newer form of modular construction has emerged: hybrid steel-concrete modular construction. Hybrid modules attempt to combine the best of both steel and concrete construction. Typically, these modules feature a steel frame with concrete walls and floors. The steel frame provides the flexibility and lightweight benefits of steel, while the concrete elements offer the strength, durability, and thermal properties of concrete. These modules can be customized to maximize the strengths of each material. For example, steel may be used where flexibility and speed are needed, and concrete may be used where strength and thermal performance are required. The steel frame is able to withstand tensile forces and provide flexibility, while the concrete walls and floors manage compressive forces and provide thermal mass, which enhances energy efficiency and thermal comfort. Concrete's density also contributes to improved sound insulation. Concrete may also be used for fireproofing purposes. By combining steel and concrete, the resulting modular building is durable, fire-resistant, and pest-resistant as well as being able to withstand environmental stresses.

The hybrid steel-concrete modules may be prefabricated off-site with both steel and concrete materials integrated, allowing for efficient on-site assembly and reduced construction time. Due to their lighter weight, the hybrid modules may be used in high-rise buildings, complex architectural projects, or structures where both flexibility and strength are required. They are also popular in areas with stringent building codes regarding fire safety and seismic performance.

However, despite all the benefits of hybrid steel-concrete modules, there are increased complexities in joining the concrete and steel elements of the hybrid modules. In particular, various techniques have been attempted for joining concrete walls to steel frame elements. In one joining technique, steel plates are embedded within the concrete walls at the top and bottom edges. These plates have anchor bolts or threaded inserts that connect to the steel frame. The top and bottom beams of the steel frame have corresponding holes or brackets, allowing the walls to be bolted or welded securely to the frame. If the embedded steel plates in the concrete walls extend slightly beyond the wall surface, they can be directly welded to the steel beams. This method ensures a rigid connection but requires precision in alignment during construction. Other connection techniques involve casting different steel components into the concrete walls.

However, none of these techniques provides a sufficiently strong and reproducible joining technique as embedded plates can pull out of the wall structure or require stringent tolerances. Further, none of these techniques add to the structural support of the module. Thus, there is a need in the art for improved concrete wall structures that can securely integrate concrete and steel components within hybrid steel-concrete modules as well as increase the structural wall support. The present invention addresses this need.

SUMMARY OF THE INVENTION

In a first aspect, the present invention provides a hybrid steel-concrete module for modular construction. The hybrid steel-concrete prefabricated modules include a steel frame and concrete wall panels. The steel frame includes steel support columns connected at a first end to steel longitudinal ceiling beams and connected at a second end to steel longitudinal floor beams. Plural lightweight concrete wall panels are positioned between the steel longitudinal ceiling beams and the steel longitudinal floor beams. Each concrete wall panel includes a lightweight concrete panel reinforced with plural steel reinforcing bars, the steel reinforcing bars connected at one end to a first steel angle at a top end of the lightweight concrete panel. A second steel angle is positioned at the bottom end of the lightweight concrete panel. A first connection is made between the first steel angle and a longitudinal ceiling beam, and a second connection is made between the second steel angle and a longitudinal floor beam.

In a further aspect, grout connections are formed between adjacent lightweight concrete wall panels.

In a further aspect, a plurality of horizontal cross beams between the steel longitudinal ceiling beams.

In a further aspect, a floor panel positioned between the longitudinal floor beams.

In a further aspect, the first and second connections are welds.

In a further aspect, the lightweight concrete has a density of 1500 kg/m³ or less.

In a further aspect, the lightweight concrete is a foamed concrete.

In a further aspect, the lightweight foamed concrete includes fiber reinforcement.

A multi-story building may be formed from plural hybrid steel-concrete prefabricated modules.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are hereafter described, by way of non-limiting example only, with reference to the following drawings in which:

FIG. 1A is a perspective view of a module according to an embodiment of the present invention;

FIG. 1B is a side view of the module of FIG. 1A depicting a perimeter wall;

FIG. 2 is a cross-section of a wall for the module of FIG. 1B;

FIG. 3 is sectional view of a wall for the module of FIG. 1B depicting the connection between wall panel with ceiling beam and floor beam;

FIG. 4 is a perspective view of connections between and steel angle and steel reinforcing bars for the wall panels of FIG. 2;

FIG. 5 is a detailed cross-sectional view illustrating a staggered reinforcing bars arrangement;

FIGS. 6-8 are views of buildings formed from the modules of FIG. 1A.

DETAILED DESCRIPTION

FIG. 1A depicts a hybrid steel-concrete module 10 for MiC multi-storey buildings according to an embodiment of the present invention. In particular, the concrete of the hybrid steel-concrete module may be a lightweight concrete. As used herein, the term “lightweight concrete” means concrete that is generally below a density of 2000 kg/m³. In one aspect, it relates to concrete that is substantially lower density than that made using aggregates of normal density; The lightweight concrete used in the MiC system of the present invention may be selected from various types, including cellular concrete, foamed concrete (for non-structural components) or lightweight aggregated concrete.

As seen in FIG. 1A, the module 10 of the present invention includes a steel frame composed of four support columns 15a-15d which are connected to both longitudinal ceiling and floor beams 20a-20d and to horizontal ceiling and floor cross beams 25a-25d. The columns and beams may be connected through any conventional steel joining techniques including welding, bolts, and rivets. Lateral roof supports 40 and lateral floor supports 50 are also used to provide structural rigidity and to support ceiling and floor components.

Structural light-weight concrete wall panels 30 form the shear walls 60. The wall panels are discussed in further detail below in connection with FIGS. 2-4. The lightweight concrete wall panels are installed between the ceiling and floor beams 25a-25d. The wall panels are connected to the floor and ceiling beams using end steel angles 34, best seen in FIG. 2. These steel angles are welded via welds 34 to the ceiling and floor beams 20a and 20c to securely support the wall panels. This construction method allows the lightweight concrete wall panels to be firmly connected between the structural ceiling and floor beams. The ceiling and floor welds may be single bevel butt welds on the external side and fillet welds on the internal side.

To ensure the engagement between the steel angles 34 and the panels 30, the steel reinforcing bars 36 are connected to the steel angles 34. Optionally, the steel reinforcing bars 36 may be organized in a staggered configuration, as seen in FIG. 4. However, a linear configuration is also possible. As seen in FIG. 3, steel reinforcing bars 36 are interconnected between a steel angle 34 at the both the top and the bottom of a panel 30.

Once the wall panels 30 have been connected to the floor and ceiling beams, grout is applied in the joints 62 between adjacent wall panels 30 as well as the joints 57 between wall panels 30 and floor panel 55. By filling the gaps between adjacent panels and between the panels and the floor panel, a continuous connection is formed, improving load transfer between module components and enhancing the overall structural integrity. Further, grout can also help seal the joints between modules, preventing water infiltration and improving fire resistance. Optionally, a combination of grout and a sealant may be used to achieve both structural and sealing purposes. The grouted joints improve the acoustic performance by reducing sound transmission between adjacent modules and enhance fire resistance by sealing gaps that could allow fire or smoke to spread between different areas of the building.

Typically, a non-shrink grout or low-shrink grout is used because it remains dimensionally stable as it cures, ensuring that the connections remain stable without any gaps forming over time. Grouts including polymers such as acrylics, polyurethanes, vinyls, polyesters, styrene-acrylics, polyvinyl acetate, epoxy, and styrene-butadiene resins may be used. The grout is selected based on the required strength and durability as well as chemical resistance.

In addition to the functions set forth above, the use of grouts also fills in any gaps due to dimensional mismatch; in this manner, all of the elements of module 10 firmly fit together, reducing the rejection of parts since a wider dimensional tolerance is practical. In modular construction, the use of grout helps to address the challenges of precision and tolerance, ensuring that all elements fit together tightly and function as a unified structure.

FIGS. 6-8 depict views of high rising housing units using the modules 10 of FIG. 1A. Each unit is one module 10 to create residential buildings. However, it is understood that plural modules 10 can be coupled together to form a larger unit configuration with multiple bedrooms, bathrooms, living room and kitchen. In general, the modules 10 may be flexibly configured in groups; further, module 10 can be formed in shapes different from that shown in FIG. 1A. It is anticipated that a building could include any suitable number and configuration of modules according to the embodiments of the invention. Due to the flexibility of the modular wall panels in the modules of FIG. 1A, window cut-outs are easily configured by removing a single panel (for example, for floor-to-ceiling windows) or installing a panel of any selected height in place of a full-length panel where windows are to be installed.

Example

The following example relates to a particular formed wall panel. It is understood that the materials of the formed panel may vary from the below materials and particular selected features.

FIGS. 1A-1B depict a module formed according to the present invention. In FIG. 1A, a lightweight foamed concrete is selected for wall panels 30. An example composition was used to form a lightweight concrete panel 30. The composition ingredients are set forth below it Table 1 showing the density of each ingredient:

Lightweight cellular concrete is prepared by mixing the pre-formed foam from Table 1 into the cementitious slurry to achieve a porous structure with uniformly dispersed air cavities. To achieve high compressive strength, advanced material technology and optimized mixing and pre-formed foam generation condition are employed to control the size distribution of air cavities and to reduce the ratio of connected cavities within cellular concrete.

In the composition of Table 1, polypropylene (PP) fibers and foamed technology to improve the performance of lightweight foamed concrete. The properties of the formed lightweight foamed concrete of Table 1 are set forth below:

The present invention offers significant advancements in the field of modular construction, specifically in the development of lightweight hybrid steel-concrete modules with enhanced structural integrity. The synergistic integration of reinforcement, steel angles, and lightweight foamed concrete results in a more cohesive and robust structural system. Consequently, the modules exhibit superior load-bearing capacity compared to conventional designs. The welded connection between the reinforcement and steel angles significantly improves the wall panels' resistance to lateral loads, a critical factor in high-rise building applications. This enhanced structural performance expands the potential applications of these modules, particularly in the context of high-rise buildings. Furthermore, the innovative design of the wall panels facilitates more efficient installation within the module. This design optimization not only streamlines off-site fabrication processes but also enhances the overall constructability of buildings utilizing these modules. As a result, the present invention's modules are suitable for a wide spectrum of construction projects, with particular efficacy in high-rise developments.

The foregoing description of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations will be apparent to the practitioner skilled in the art.

While the present disclosure has been described and illustrated with reference to specific embodiments thereof, these descriptions and illustrations are not limiting. It should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the present disclosure as defined by the appended claims. The illustrations may not necessarily be drawn to scale. There may be distinctions between the artistic renditions in the present disclosure and the actual apparatus due to manufacturing processes and tolerances. There may be other embodiments of the present disclosure which are not specifically illustrated. The specification and the drawings are to be regarded as illustrative rather than restrictive. Modifications may be made to adapt a particular situation, material, composition of matter, method, or process to the objective, spirit and scope of the present disclosure. All such modifications are intended to be within the scope of the claims appended hereto. While the methods disclosed herein have been described with reference to particular operations performed in a particular order, it will be understood that these operations may be combined, sub-divided, or re-ordered to form an equivalent method without departing from the teachings of the present disclosure. Accordingly, unless specifically indicated herein, the order and grouping of the operations are not limitations.