FISH SCALE-CELLULAR COMPOSITE SYSTEM AGAINST IMPACT

Ph.DDOCTOR OF PHILOSOPH

Robustness of Prefabricated Prefinished Volumetric Construction (PPVC) High-rise Building

[EN] Due to the safety awareness arisen from natural and human-caused disasters, robustness design of building is increasingly important to ensure the stability of the building and to prevent progressive collapse. For this reason, the robustness design of innovative construction technologies such as modular construction may be essential due to its relative novel structural form and numerous joints among modules. Particularly in Singapore, Prefabricated Prefinished Volumetric Construction (PPVC) has been highly promoted in residential and commercial buildings, hostels and hospitals to boost the construction productivity and quality as well as to reduce the reliance on foreign workforce. PPVC offers high quality and efficiency because most of the finishes and mechanical and electrical services are manufactured and installed together with the modules in factory, before sending for on-site assembly. To maximize the productivity of PPVC, modular design standardization and repetition can be improved by going for high-rise. Nonetheless, there are limited studies on the robustness of PPVC high-rise building and its behavior under progressive collapse remains uncertain. Therefore, this paper investigates the robustness of steel PPVC high-rise building under column removal scenarios by conducting non-linear numerical analysis. The effects of joint design and diaphragm action between modules are studied to ensure continuity of horizontal and vertical tying. This paper provides insight on the behaviour and alternative path for load transfer under column removal scenario for future design guideline of robustness PPVC building.The authors would like to acknowledge the financial support by the National Research Foundation (NRF) and SembCorp-NUS Corp Lab under project grant R-261-513-009-281Chua, YS.; Liew, JYR.; Pang, SD. (2018). Robustness of Prefabricated Prefinished Volumetric Construction (PPVC) High-rise Building. En Proceedings of the 12th International Conference on Advances in Steel-Concrete Composite Structures. ASCCS 2018. Editorial Universitat Politècnica de València. 913-919. https://doi.org/10.4995/ASCCS2018.2018.6955OCS91391

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

10.1016/j.istruc.2019.02.010Structures21135-14

Modelling of connections and lateral behavior of high-rise modular steel buildings

10.1016/j.jcsr.2019.105901Journal of Constructional Steel Research16610590

Robustness of inter-module connections and steel modular buildings under column loss scenarios

https://doi.org/10.1016/j.jobe.2021.103888Journal of Building Engineering4

Research on structural performance of hybrid ferro fiber reinforced concrete slabs

Reinforced concrete structures, particularly in cold areas, experience early deterioration due to steel corrosion. Fiber-Reinforced Concrete (FRC) is an emerging construction material and cost-effective substitute for conventional concrete to enhance the durability and resistance against crack development. This article examines the structural performance of hybrid ferro fiber reinforced concrete slabs (mix ratio of mortar 1:2) comprising silica fume, layers of spot-welded mesh and different ratios of polypropylene fibers. The ferrocement slabs are compared with a conventional Reinforced Cement Concrete (RCC) slab (mix ratio of 1:2:4). The experimental work comprised a total of 13 one-way slabs, one control specimen and three groups of ferrocement slabs divided based on different percentages of Poly Propylene Fibers (PPF) corresponding to 0.10%, 0.30% and 0.50% dosage in each group. Furthermore, in each group, the percentage of steel ratio in ferrocement slabs varied between 25% and 100% of the steel area in the reinforced concrete control slab specimen. For evaluating the structural performance, the observation of deflection, stress-strain behavior, cracking load and energy absorption are critical parameters assessed using LVDTs and strain gauges. At the same time, the slabs were tested in flexure mode with third point loading. The experimental results showed that the first cracking load and ultimate deflection for fibrous specimens with 0.5% fiber and 10% silica fume increased by 15.25% and 13.2% compared with the reference RCC control slab. Therefore, by increasing the percentage of PPF and steel wire mesh reinforcement in the ferrocement slab, the post-cracking behavior in terms of deflection properties and energy absorption capacity was substantially enhanced compared to the RCC control slab

Effect of design variation in behaviour and performance of Endplate-Type intermodular connection

Intermodular connections play an important role in the constructability and performance of modular building structures. The wind-generated vertical uplift force and the lateral load on modular structures raise concerns about the tensile and shear capacity of the intermodular connection joints. This study focuses on investigating the change in load response behaviour, working mechanism and performance of endplate-type intermodular connections with varying design parameters. Initially, the paper presents the design criteria of endplate-type intermodular connections and their behaviour, with a detailed theoretical approach, to identify their performance and capacity under tensile and shear loads. Then, the capacity of the proposed connections in this study was evaluated based on both the presented theoretical design and numerical approaches. The design inspiration for the proposed connection was taken from literature using which the finite element models for 4 specimens were developed and validated. The validated connection models were then used to conduct parametric studies for 11 proposed models, focused on changes in base endplate thickness (8 mm, 10 mm and 12 mm) and steel grade (s275 and s355), bolt hole diameter (22 mm, 26 mm and 30 mm) and tolerance, bolt grade (8.8, 10.9 and 12.9) and applied preload (0, 50 kN, 90 kN and 110 kN) with and without additional plate over oversized bolt holes. The results obtained from both shear and tensile performance analysis indicate that the change in proposed design parameters has a greater impact on shear over tensile behaviour and capacity. Further, the conducted parametric studies helped in identifying the optimum design parameter combinations for enhanced connection performance which are also cost-effective and ideal for an onsite installation. Finally, the paper suggests recommendations for future research and essential advancement in the endplate-type intermodular connection design in enhancing performance and presents the practical limitations and challenges in using such techniques