Abstract:
U-Boot Beton is a cast-in-place biaxial voided slab technology in which recycled plastic modules are embedded within the slab section to reduce the volume of concrete in regions that contribute minimally to structural resistance. This approach significantly decreases the self-weight of the structure while preserving the load-bearing behavior of conventional reinforced-concrete flat slabs. This paper examines the structural performance of the U-Boot Beton system, its construction procedures, and the critical quality control requirements associated with its practical application in Vietnam. The study is based on a comprehensive review of technical literature and a comparative analysis with current Vietnamese design standards. The findings indicate that the technology offers substantial benefits in terms of weight reduction and architectural flexibility; however, its successful implementation requires more rigorous design verification and quality management, particularly in slab–column connection zones where punching shear and load transfer are critical considerations.
Keywords: U-Boot Beton, voided slab, flat slab, concrete construction, punching shear, reinforced concrete structure.
1. Introduction
The rapid development of multi-story buildings in Vietnam has created demand for structural solutions that are efficient in load resistance while also optimizing materials and usable space. Among these, beamless flat slabs are highly valued because they provide a continuous ceiling surface and facilitate spatial planning as well as the arrangement of building services. However, when slab spans increase, the traditional solid slab option becomes less attractive because its high self-weight increases the loads transmitted to columns and foundations.
To reduce dead load while maintaining structural performance, biaxial voided slab systems have received growing attention. U-Boot Beton is one of the representative solutions, based on the principle of removing the less effective concrete in the cross-section. Although the system has already been used in several domestic projects, a more systematic assessment is still needed to clarify the conditions under which it can be appropriately applied in Vietnam.
2. Research approach
The paper is developed through a review of technical documents related to the U-Boot Beton slab system, combined with international studies on the behavior of biaxial voided slabs and the provisions of Vietnamese reinforced-concrete design standards. On that basis, the main characteristics of the system are examined to clarify its mechanical nature, construction requirements, and the technical risks that may arise during implementation.
Because the paper does not focus on a specific project, the conclusions are general in nature and depend on the selected structural configuration. The comparison with standards is intended to ensure that the analysis remains consistent with requirements for strength, stiffness, and long -term performance under practical construction conditions.
3. Analysis and discussion
3.1 Structural characteristics
The essence of the U-Boot Beton slab lies in the redistribution of material within a flexural section. Instead of using solid concrete throughout the thickness, the system removes concrete in the neutral - zone region, where stresses are relatively small, and replaces it with hollow boxes. As a result, self - weight is reduced while the concrete in the compression and tension zones is retained to ensure load-carrying capacity.
The interaction between concrete and reinforcement enables the slab to continue working as a two-way system similar to a conventional flat slab. Nevertheless, because the sectional geometry is modified, parameters such as flexural stiffness and shear resistance are also affected to some extent. In particular, near columns where internal forces are highly concentrated, punching failure becomes the governing concern and must be carefully addressed in design detailing.
3.2 Construction sequence and execution control
Construction of a U-Boot Beton slab follows a cast-in-place sequence, beginning with support preparation and ending with concrete finishing. First, the formwork and shoring system must be erected with adequate stability and geometric accuracy because this stage governs the quality of all subsequent work. Based on that support system, the bottom reinforcement is installed together with spacers to maintain the required concrete cover.
After the lower steel has been completed, the hollow modules are positioned according to the prescribed grid and tied in place to prevent movement during concreting. Control of module location is crucial because any deviation may alter the effective working section of the slab. Next, the top reinforcement and local strengthening details are installed, especially in heavily loaded areas such as around columns or near slab openings.
Concrete placement is often divided into two stages in order to preserve the stability of the hollow modules and achieve uniform concrete quality. After casting, curing and formwork removal must follow technical requirements so that the structure gains sufficient strength before carrying construction or service loads.
3.3 Practical applicability in Vietnam
Under Vietnamese construction conditions, the U-Boot Beton slab can be effective in buildings that require large spans and flexible interior layouts. Reducing the slab self - weight not only benefits the floor itself but can also improve the performance of the entire structural system, from columns to foundations.
However, these benefits are not automatic. They depend on design capability, site execution, and the level of quality control. Verification of strength, deflection, and punching shear must be carried out fully in accordance with applicable standards. At the same time, the construction process requires a high degree of precision; otherwise, the expected efficiency of the solution may be significantly reduced.
4. Conclusion and future directions
The U-Boot Beton slab represents a rational approach to improving material efficiency and reducing structural dead load. With its technical and architectural advantages, the technology has significant potential for application in a wide range of projects in Vietnam.
To use the system effectively, however, close coordination between design and construction is essential, with particular attention to sensitive regions such as slab - column connections. The development of more detailed domestic technical guidance, together with further experimental research, would provide a stronger basis for safer and wider adoption in the future.
References
[1] Ministry of Science and Technology. (2018). TCVN 5574:2018 - Design of concrete and reinforced concrete structures.
[2] Nam, N. H. (2017). Quality management for the construction of voided slabs in Vietnam.
[3] Daliform Group. (n.d.). U-Boot Beton Technical Documentation.
[4] Oukaili, N., et al. (2024). Punching shear resistance of voided slabs. Buildings.
[5] Chung, J.-H., Jung, H.-S., & Choi, H.-K. (2022). Flexural behavior of voided slabs. Applied Sciences.
[6] Sagadevan, R., & Rao, B. N. (2019). Punching shear of voided slabs. Structures.
Công nghệ sàn U-Boot Beton và khả năng áp dụng trong điều kiện thi công tại Việt Nam
Trần Thanh Vũ1
Cao Hữu Lợi1
1Đại học Trà Vinh
Tóm tắt:
U-Boot Beton là công nghệ sàn rỗng hai chiều thi công toàn khối, trong đó các mô-đun nhựa tái chế được bố trí bên trong tiết diện sàn nhằm giảm thể tích bê tông tại những vùng ít tham gia chịu lực. Giải pháp này giúp giảm đáng kể trọng lượng bản thân của kết cấu, đồng thời vẫn duy trì cơ chế chịu lực của sàn phẳng bê tông cốt thép truyền thống. Nghiên cứu này phân tích khả năng làm việc kết cấu của hệ sàn U-Boot Beton, quy trình thi công và các yêu cầu kiểm soát chất lượng quan trọng khi áp dụng trong thực tiễn tại Việt Nam. Nghiên cứu được thực hiện trên cơ sở tổng quan toàn diện các tài liệu kỹ thuật và so sánh, đối chiếu với các tiêu chuẩn thiết kế hiện hành của Việt Nam. Kết quả cho thấy công nghệ này mang lại những lợi ích đáng kể về giảm tải trọng bản thân và tăng tính linh hoạt trong thiết kế kiến trúc; tuy nhiên, việc triển khai hiệu quả đòi hỏi quy trình kiểm tra thiết kế và quản lý chất lượng chặt chẽ hơn, đặc biệt tại khu vực liên kết sàn–cột, nơi khả năng chống chọc thủng và cơ chế truyền lực đóng vai trò quyết định.
Từ khóa: U-Boot Beton, tấm sàn rỗng, tấm sàn phẳng, kết cấu bê tông, lực cắt xuyên, kết cấu bê tông cốt thép.
[Tạp chí Công Thương - Các kết quả nghiên cứu khoa học và ứng dụng công nghệ, Số 13 năm 2026]
