scholarly journals Steel Concrete Composite Systems for Modular Construction of High-rise Buildings

2018 ◽  
Author(s):  
Richard JY Liew ◽  
Z. Dai ◽  
Yie Sue Chau
Keyword(s):  
Structural Integrity ◽  
Lightweight Concrete ◽  
Work Force ◽  
Innovative Technology ◽  
Modular Construction ◽  
High Rise ◽  
Modular Units ◽  
Speed Up ◽  
Strength And Stiffness ◽  
Tolerance Control

Modular construction has gained popularity and attention particularly in low-rise building lately due to its numerous advantages: faster construction speed, better quality control, reduction in work force and construction waste, etc. This innovative technology promotes off-site manufacturing of modular units and on-site assembly, improving the construction efficiency and productivity. However, modular construction is not commonly used in high-rise buildings because of the joints’ flexibility as well as manufacturing and construction tolerance, which have significant impact on the overall stability of the building. This paper highlights the existing challenges of modular construction of high-rise buildings and provide several options to address these challenges. Firstly, the weight of a module is constrained by the transportation and lifting crane capacities. For this reason, lightweight concrete is introduced together with structural steel section to form lightweight steel-concrete composite system to reduce the weight of the module without compromising the strength and stiffness. Secondly, to speed up the site assembly of modular units, special joints are developed to resist the forces due to gravity and horizontal loads. Fast and easy joining techniques with acceptable tolerance control are essential to ensure the structural integrity and stability of the building. Finally, the innovation for productivity can be maximized by implementing automation technologies in the manufacturing and construction of the modular units.

scholarly journals Tower Crane Location Optimization for Heavy Unit Lifting in High-Rise Modular Construction

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 121
Author(s):  
Hosang Hyun ◽  
Moonseo Park ◽  
Dowan Lee ◽  
Jeonghoon Lee
Keyword(s):  
Low Cost ◽  
Modular Construction ◽  
Algorithm Optimization ◽  
Location Selection ◽  
Project Completion ◽  
High Rise ◽  
Tower Crane ◽  
Proposed Model ◽  
Study Results ◽  
Crane Selection

Modular construction, which involves unit production in factories and on-site work, has benefits such as low cost, high quality, and short duration, resulting from the controlled factory environment utilized. An efficient tower crane lifting plan ensures successful high-rise modular project completion. For improved efficiency, the lifting plan should minimize the reaching distance of the tower crane, because this distance directly affects the tower crane capacity, which is directly related to crane operation cost. In situations where units are lifted from trailers, the trailer-to-tower crane distance can have a significant impact on the tower crane operation efficiency. However, optimization of this distance to improve efficiency has not been sufficiently considered. This research proposes a genetic algorithm optimization model that suggests optimized tower crane and trailer locations. The case study results show that through the proposed model, the project manager can reflect the optimal location selection and optimal tower crane selection options with minimal cost.

Timber-concrete composite frame joint for high-rise buildings

2019 ◽  
Author(s):  
Tim Höltke ◽  
Achim Bleicher
Keyword(s):  
High Strength ◽  
Specific Weight ◽  
Modular Construction ◽  
Renewable Materials ◽  
Load Bearing ◽  
Laminated Veneer Lumber ◽  
High Rise ◽  
Composite Frame ◽  
Composite Joint ◽  
First Results

<p>Timber is one of the few renewable materials that improves its structural properties when combined with concrete. The composite of timber and concrete increase stiffness and fire protection, unlike timber when used alone. In contrast to concrete structures, timber-concrete composite (TCC) structures reduce the carbon footprint and the specific weight of a building. At the Chair of Hybrid Structures - Structural Concrete of BTU Cottbus-Senftenberg a moment-resistant TCC joint was developed for multi-story frames, which can be used as a structural system for high-rise buildings. Facts like a modular construction, a fast assembly and a plug-in connection were aspects that shaped the development. A high rotational stiffness and load-bearing at the composite joint was also achieved using high strength beech laminated veneer lumber (LVL).</p><p>The TCC frame works on its own and in combination with other bracing systems. Initial investigations on the load-bearing behavior were carried out using numerical analysis followed by experiments on real-sized joints in further studies. First results will be presented in this paper. The developed TCC joint as part of structural systems offers a high variability and can thus contribute to tomorrow’s sustainable vertical growth of cities.</p>

scholarly journals Studying the influence of the cross section height on the distribution of the internal efforts of wooden glued beams

2019 ◽  
Vol 135 ◽  
pp. 03048
Author(s):  
Sergei Prokhorov
Keyword(s):  
Cross Section ◽  
High Strength ◽  
Large Error ◽  
Environmental Friendliness ◽  
High Rise ◽  
Reinforced Beams ◽  
Flexural Member ◽  
Strength And Stiffness ◽  
Capital Construction ◽  
Wooden Structures

Since ancient times, wooden structures have been used by man for the construction of buildings and facilities. For many centuries, the structural elements of buildings and facilities made of wood have been the main ones, and still have broad prospects for use in modern capital construction, as they have sufficient high strength and stiffness, are reliable and durable, while having a small mounting weight. In particular, a number of Western countries are already erecting high-rise buildings using a framework of laminated wood constructions. The indisputable advantage of wooden structures is environmental friendliness. However, with all the harmony of the wood structure, its tracheid’s are not standard, which is the main reason for the variability of its mechanical properties. With alteration of a cross-section of flexural member, the nature of the load distribution, as well as the nature of the fracture, changes. An additional factor that affecting the force distribution is the nature of the reinforcement and methods of the reinforcement fixing methods. The methods used to calculate the “low” reinforced beams often give a large error in the calculation of “high” beams. In the work, a rational methodology for calculating wooden glued reinforced beams with symmetrical reinforcement is determined.

Some life-history consequences of modular construction in plants

1986 ◽  
Vol 313 (1159) ◽  
pp. 31-51 ◽  
Keyword(s):  
Life History ◽  
Clonal Plants ◽  
Modular Construction ◽  
Death Rates ◽  
Relative Growth Rates ◽  
Apical Meristems ◽  
Modular Units ◽  
Single Shoot ◽  
Dead Material ◽  
Weak Constraints

The nature and life-history consequences of modular construction in plants are discussed with particular reference to growth, reproduction and survival. Plants grow by the iteration of modular units and as a consequence growth can be described in terms of the population dynamics of these structural units. Changes in size, whether positive or negative, depend on the birth and death rates of modules; however, if the births continue to exceed the deaths, plants then have the capability of attaining enormous sizes, especially if they are clonal. The population nature of plant growth also means that plants of the same age may show large variation in individual size if individuals differ in their relative growth rates. Correlations between age and size are often, therefore, very weak. Constraints on the allocation of resources accumulated during growth have important implications for the reproductive schedules of plants, but the analysis of constraint functions has so far revealed little about the actual detail of these schedules. All the meristems of semelparous plants are involved in or die at reproduction and as a consequence death of the genet follows reproduction. For iteroparous plants, however, there are fundamental differences between the reproductive schedules of plants with a single shoot module and those with many shoot modules. The former demonstrate a relatively constant rate of reproduction from year to year following maturity whereas the latter show a continual increase in fecundity with size and age. The reproductive schedules of clonal plants are further discussed in relation to the allocation of meristems to either growth or reproduction. The pattern of mortality is examined at both the level of the module and the genet. Particular attention is focused on the survival and senescence of leaves and shoots; there is no equivalent regular shedding of organs in unitary organisms. Whereas genet senescence and death are coincident with shoot module death in semelparous plants, there is no evident relation between them in iteroparous plants. The life span of the genet reflects the birth and death rates of its modules and both aclonal and clonal plants that are iteroparous may achieve considerable longevity. The longevity of aclonal plants often seems to be restricted by the accumulation of dead material and the problems of being large. Clonal plants are, in contrast, potentially immortal. It is questionable whether the genets of iteroparous plants show senescence as defined for unitary organisms since there is no separation of germ plasm from soma and since apical meristems do not appear to senesce. Insofar as they retain the capacity for rejuvenescence from apical meristems, genets of modular organisms do not senesce; it is only the constituent organs that show senescence, death and decay.

scholarly journals An observer‐based fault tolerance control system with a static filter and its application to high‐rise buildings

2020 ◽  
Vol 2 (6) ◽  
Author(s):  
Chao‐Jun Chen ◽  
Zuo‐Hua Li ◽  
Jun Teng ◽  
Qing‐Gui Wu ◽  
Bei‐Chun Lin
Keyword(s):  
Control System ◽  
Fault Tolerance ◽  
High Rise ◽  
Tolerance Control

scholarly journals Enhancing Functionality of Epoxy–TiO2-Embedded High-Strength Lightweight Aggregates

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2384 ◽  
Author(s):  
Taekyung Lim ◽  
Jeong Hui Lee ◽  
Ju-Hyun Mun ◽  
Keun-Hyeok Yang ◽  
Sanghyun Ju ◽  
...  
Keyword(s):  
Tio2 Nanoparticles ◽  
Large Scale ◽  
Lightweight Concrete ◽  
High Strength ◽  
Air Pollutant ◽  
Mixed Solution ◽  
Research Attention ◽  
High Rise ◽  
Structural And Functional Properties ◽  
Architectural Structures

With the increasing trend of high-rise, large-scale, and functional modern architectural structures, lightweight aggregate (LWA) concrete that exhibits excellent strength and high functionality has garnered active research attention. In particular, as the properties of concrete vary considerably with the raw materials and the proportions of aggregates in the mix, in-depth research on weight reduction, strength improvement, and functional enhancements of aggregates is crucial. This study used the negative pressure coating of a mixed solution comprising epoxy (mixture of epoxy resin and crosslinker), hyper-crosslinked polymer, and titanium oxide (TiO2) nanoparticles on the LWA, and achieved an improvement in the strength of the LWA as well as a reduction in air pollutants such as NOx and SOx. Compared to a normal LWA with an aggregate impact value (AIV) of 38.7%, the AIV of the proposed epoxy–TiO2-embedded high-strength functional LWA was reduced by approximately half to 21.1%. In addition, the reduction rates of NOx and SOx gases resulting from the photocatalytic properties of TiO2 nanoparticles coated with epoxy were approximately 90.9% and 92.8%, respectively. Epoxy–TiO2, embedded in LWAs through a mixture, exhibited stability, high strength, and a reduction in air pollutant characteristics, despite repeated water washing. The LWA proposed herein offers excellent structural and functional properties and is expected to be used in functional lightweight concrete that can be practically applied in high-rise and large-scale architectural structures.

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