Brabha Nagaratnam

Brabha Nagaratnam
Northumbria University · Department of Architecture, Engineering and Construction

PhD

About

72
Publications
31,773
Reads
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1,298
Citations
Introduction
Brabha Nagaratnam currently works at the Department of Civil and Construction Engineering, Northumbria University, UK. Brabha does research in Civil Engineering, 3D printing for construction and Materials Engineering.
Additional affiliations
February 2010 - present
Curtin University Sarawak
Position
  • Lecturer

Publications

Publications (72)
Article
Full-text available
Early-age shrinkage of concrete can initiate premature cracking, which can compromise the durability of concrete structures. Monitoring capillary pressure, the leading cause of concrete shrinkage, and understanding its evolution is crucial for the performance-based design of concrete, particularly at early-stages when it is more prone to cracking....
Article
Construction industries have increasingly sought to adopt Cold‐Formed Steel (CFS) sections as primary and secondary load‐carrying members. Also, the evolution of the CFS industry leads to fabrication of high strength CFS sections due to their added benefits such as higher strength‐weight ratio, most appropriate to employ in high‐rise and long‐span...
Article
This study presents a comprehensive evaluation of the shear behaviour of bolted intermodular connections under lateral load using theoretical, experimental, and numerical approaches. Three design configurations with varying bolt sizes and hole tolerances of the proposed bolted intermodular connection were established and tested under lateral load t...
Article
In the current evolving building construction sector, the use of cold‐formed steel frames (CSF) has gained popularity due to their fast, clean, and flexible constructability. On the other side, in terms of the energy efficiency of a building, the use of CSF has raised concerns due to their high thermal conductivity, especially in the case of extern...
Article
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...
Chapter
Owing to their high surface-to-volume ratio, concrete pavements and slabs are more prone to shrinkage, leading to premature cracking and, as a result, loss of serviceability. Capillary pressure in concrete, identified as the main contributor to shrinkage, needs to be frequently monitored to evaluate the shrinkage behaviour of concrete. However, cap...
Article
Lightweight high strength concrete (LWHSC), which combines the properties of both lightweight concrete (LWC) and high strength concrete (HSC), is gaining popularity due to its increased strength and reduced self-weight, that are easier to handle and provide economic benefits. However, LWHSC is particularly sensitive to its material constituents and...
Presentation
Full-text available
I am pleased to invite esteemed researchers and engineers to consider submitting their latest research to the special issue "Research Advances in Sustainable Materials and Structural Engineering" in the Journal of Sustainability by MDPI. Research topics may include, but are not limited to: - Efficient use of building materials - Composite material...
Article
Full-text available
Modular building systems (MBS) and Origami are two emerging methods used in current construction practice. Origami is directly associated with the principles of the ancient Japanese art of paper folding, characterised by high morphological possibilities and ultimately creates foldable structures with tuneable mechanical properties. However, there i...
Article
Capillary pressure is frequently measured to evaluate the shrinkage performance of concrete but has been limited to pressures <100 kPa preventing a better understanding of the early age factors affecting concrete durability. In this study, high capacity tensiometers (HCTs) were employed for the first time to investigate the behavior of early age co...
Article
Full-text available
The steel Modular Building Systems (MBSs) that have been influenced by the Light-gauge Steel Frame (LSF) techniques have become a prominent culture in the industry. However, the detrimental behaviour of steel structural components at high temperatures has elevated the risk of fatal accidents in the event of a fire. Although several research investi...
Article
Full-text available
Concrete-infilled hollow flange cold-formed steel (CF-HFCFS) beams have gained attention in the construction practices owing to many benefits in terms of their structural performances and applicability. The concrete infill ensures better structural performance by restraining the buckling instabilities of thin-walled cold-formed steel elements. Howe...
Article
Full-text available
The large-scale additive manufacturing (AM), well-recognized as 3D concrete printing is developing and therefore gained intensive research attention. However, this technology is requiring appropriate specifications and standard guidelines. Furthermore, the performance of printable concrete in elevated temperature circumstances is still not explored...
Article
Full-text available
Flexural behaviour and design of hollow flange cold-formed steel 1 beam filled with lightweight normal and lightweight high strength 2 concrete 3 Mohamed Sifan Abstract 26 A comprehensive investigation of the flexural behaviour of concrete-infilled hollow flange cold 27 formed steel (CF-HFCFS) beams with lightweight normal and lightweight high stre...
Article
Full-text available
The construction industry plays an important role in economic growth, conflicts occurred in the project phases will slow down the construction progress, or driving to the worst scenario in abandoning the project. Negotiators need to overcome the conflict and smoothen the progress of the construction project with minimum harm to project stakeholders...
Article
Full-text available
Lightweight Steel Frames (LSF) in building construction are becoming more popular due to their fast, clean, and flexible constructability. Typical LSF wall panels are made of cold-formed and thin-walled steel lipped channel studs with plasterboard linings. Due to the high thermal conductivity of steel, these LSF components must be well engineered a...
Article
Full-text available
Awareness of sustainability in construction has led to the utilization of waste material such as oil palm shell (OPS) in concrete production. The feasibility of OPS as alternative aggregates in concrete has been widely studied at the material level. Meanwhile, nonlinear concrete material properties are not taken into account in the conventional con...
Article
The Modular Building System (MBS) is increasingly popular and promoted due to the inherent advantages over conventional construction. Fire performance of a building has become a crucial design consideration because of the recent detrimental fire accidents. However, for modular buildings, there has been less previous evidence of research on the fire...
Article
A comprehensive investigation of the flexural behaviour of concrete-infilled hollow flange cold formed steel (CF-HFCFS) beams with lightweight normal and lightweight high strength concrete is presented in this paper. These are new generation of complex members, and their enhanced structural capacity is governed by inter-related parameters including...
Article
Full-text available
Three-dimensional-printed concrete (3DPC), which is also termed as digital fabrication of concrete, offers potential development towards a sustainable built environment. This novel technique clearly reveals its development towards construction application with various global achievements, including structures such as bridges, houses, office buildin...
Conference Paper
Steel fibre-reinforced self-compacting concrete (SFRSCC) combines the benefits of SCC of high flowability and randomly dispersed steel fibres together in one single concrete. Steel fibres prevent brittle behaviour and improve several mechanical properties of SCC. In this paper, an experimental investigation of the effect of three-dimensional (3D) s...
Article
Modular Building System (MBS) is an emerging offsite construction technique, which uses prefabricated units, transported, and assembled onsite. In MBS construction process, designing stage is considered as the most significant stage. One of the critical concerns in designing MBSs is to maintain and to ensure the structural integrity of the assembly...
Article
Full-text available
The 3-Dimensional (3D) printing technology in the construction sector has seen accelerating growth owing to its potential advantages. For this layer-based construction, a detailed investigation of fire performance is necessary. However, there are limited research studies for 3D Printed Concrete (3DPC) walls exposed to fire. Therefore, this paper in...
Article
Full-text available
Cracking in concrete structures can significantly affect their structural integrity and eventu- ally lead to catastrophic failure if undetected. Recent advances in sensor technology for structural health monitoring techniques have led to the development of new and improved sensors for real-time detection and monitoring of cracks in various applicat...
Article
Full-text available
3D Printed Concrete (3DPC) technology is currently evolving with high demand amongst researches and the integration of modular building system (MBS) with this technology would provide a sustainable solution to modern construction challenges. The use of lightweight concrete in such innovative construction methods offers lightweight structures with b...
Article
This paper presents the development of novel affordable steel-framed modular units for construction with enhanced overall (healthcare, structural, fire, and lightweight) performance, which ideally suits for emergency response situation, such as current covid-19 pandemic. The nature of quick response and well-prepared strategies are essential to cop...
Article
Purpose In this study, the insulation fire ratings of lightweight foamed concrete, autoclaved aerated concrete and lightweight aggregate concrete were investigated using finite element modelling. Design/methodology/approach Lightweight aggregate concrete containing various aggregate types, i.e. expanded slag, pumice, expanded clay and expanded sha...
Article
Full-text available
Purpose Fire safety of a building is becoming a prominent consideration due to the recent fire accidents and the consequences in terms of loss of life and property damage. ISO 834 standard fire test regulation and simulation cannot be applied to assess the fire performance of 3D printed concrete (3DPC) walls as the real fire time-temperature curves...
Article
Full-text available
Concrete is the primary building material worldwide with a substantial impact on the built environment sustainability. Hence, it is necessary to assess concrete’s combined functionality, economic and environmental impact. In this paper, two concrete sustainability assessment frameworks, MARS-SC and CONCRETop, were studied. Building on the identifie...
Chapter
Fire is one of the severe conditions in which structures may be exposed during their life span. When considering the structural elements, wall panels play a vital role during a fire scenario, since the spreading of the fire could be either controlled or accelerated due to the type of the wall partition. Standard fire tests are generally used to eva...
Chapter
Full-text available
Additive manufacturing in construction industry has been introduced as an aspiration for a more sustainable built environment and currently evolving with high demand amongst researches. This study is an investigation of the influence of polypropylene (PP) fibre addition on the workability parameters of a new extrudable concrete mixture. As the qual...
Article
Full-text available
The bending-shear interaction response of cold-formed stainless steel lipped channel sections has been given inadequate attention in the past. Therefore, this paper investigates the bending and shear interaction behaviour of cold-formed stainless steel lipped channel sections using numerical studies. Finite element (FE) models were developed and va...
Article
Timber beams in historic buildings tend to display signs of mechanical degradation in the form of large bending deformations and reduced capacity, often caused by timber defects. This paper addresses the assessment of the bending resistance of small timber beams subjected to static loads, before and after they have been reinforced using Fibre Reinf...
Conference Paper
Full-text available
This study investigates the effect of three-dimensional (3D) fibres on the fresh properties of self-compacting concrete (SCC) using three different fibre volume fractions (1%, 2% and 3%). Two different sizes of 3D fibres with perimeters of 115 mm and 220 mm were considered. Fresh properties were determined through slump flow, J-ring, V-funnel and s...
Article
The shear response of the cold-formed stainless steel lipped channel sections with longitudinal stiffeners has not been investigated adequately in the past. Therefore, this paper presents the details of numerical investigations conducted to study the shear behaviour of longitudinally stiffened cold-formed stainless steel lipped channel sections. Fo...
Chapter
Full-text available
3D Concrete Printing (3DCP) has aa potentiality to produce complex, geometries and can modify the details rapidly using a printer integrated with a pump and nozzle. From the earlier studies on 3DCP, it is distinguished that the rheological behaviour of the material, printing direction, and printing time may have significant effects on the overall s...
Article
Full-text available
Modular Building Systems (MBS) has seen an accelerating growth in the construction sector owing to its potential advantages, such as quick erection, improved energy efficiency and less reliant on good weather over conventional construction methods. Therefore, it could be a viable solution to supporting the efforts of solving Britain's housing crisi...
Article
If concrete is crack free, deleterious substances can be avoided entering the body of the material, that may corrode the rebar or encourage freeze/thaw damage. This paper examines a self healing system of cementitious materials. Microbial induced calcite precipitation was used to heal cracks in concrete with calcite using bacillus bacteria in alkal...
Chapter
Structural fire damage can be identified as a common accidental disaster throughout the world which cause thousands of deaths, injuries and millions in property damage each year. Fire represents one of the most severe conditions to which structures may be subjected. Generally, structural elements will be exposed to very high temperature (1200 ℃) du...
Conference Paper
Full-text available
The steel construction industry has recently put a lot of effort to better understand Modular Building Systems (MBS) and replaced, where possible, conventional construction methods. MBS claims promising advantages including speed of erection, improved quality, reduced cost, and flexibility. Therefore, research efforts are tuned to the structural, s...
Conference Paper
Full-text available
The development of Additive Manufacturing (AM) in the construction industry has become an innovative solution for sustainable built environment. Many researches are undertaken globally to elucidate the significance of additive manufacturing to create safer and more flexible future construction industry. There is no doubt that AM and digitalization...
Conference Paper
Full-text available
Additive manufacturing in construction industry has been introduced as an aspiration for a more sustainable built environment and currently evolving with high demand amongst researches. This study is an investigation of the influence of polypropylene (PP) fibre addition on the workability parameters of a new extrudable concrete mixture. As the qual...
Conference Paper
Full-text available
CFS beams are often provided with web openings to accommodate building services. However, the area reduction in the web affects their load-bearing capacities. The reduction of bending capacity can be regained through providing suitable stiffeners in the vicinity of the web openings and through providing the web openings to the optimised CFS beams....
Article
The demand for highly structurally efficient stainless steel is limited to a certain extent by its high initial cost. Therefore, the utilisation of material to the optimum possible level is important. In achieving this, further consideration should be given to enhance the design rules where beneficial effects such as pronounced strain hardening in...
Article
Full-text available
It is challenging to measure the environmental impact of concrete with the absence of a consensus on a standardized methodology for life cycle assessment (LCA). Consequently, the values communicated in the literature for "green" concrete alternatives vary widely between 84 and 612 kg eq CO2/m 3. This does not provide enough evidence regarding the a...
Article
Full-text available
A UK government report released in 2017 indicated that fly ash (FA) production locally is expected to seize after 2021. This means that for the construction industry to meet its continuously increasing demand for an Ordinary Portland Cement (OPC) replacement, FA would probably need to be either imported or recovered from landfills through energy-in...
Article
Full-text available
Cold‐formed steel (CFS) members have been used significantly in light‐gauge steel buildings due to their inherent advantages. Optimizing these CFS members in order to gain enhanced load bearing capacities will result in economical and efficient building solutions. This research presents the investigation and results of the optimization of CFS membe...
Conference Paper
Cold-formed steel (CFS) members, when subjected to optimisation, can significantly increase their ultimate load carrying capacity leading to a more economical and efficient structural system. This paper presents the details of an investigation on optimisation of CFS beams subjected to bending capacity and an investigation of shear and web crippling...
Article
Stainless steel is a high‐performance construction material that combines the strength and stiffness associated with ferrous alloys with the corrosion resistance derived principally from the high chromium content. Its unique combination of properties usually comes at a cost, which puts increased emphasis on ensuring that the material is utilized to...
Article
Full-text available
The use of modular building systems (MBSs) in the construction sector is increasing. MBSs enhance structural performance of buildings, quality control, and construction speed than traditional methods at a lower cost. Additional benefits can be associated with resource efficiency at both the production and construction phases, which may increase MBS...
Article
Cold‐formed steel (CFS) members, when subjected to optimisation, can significantly increase their ultimate load carrying capacity leading to a more economical and efficient structural system. This paper presents the details of an investigation on optimisation of CFS beams subjected to bending capacity and an investigation of shear and web crippling...
Conference Paper
Full-text available
The use of supplementary cementitious materials (e.g. fly ash and ground granulated blast furnace slag) as a partial replacement of ordinary Portland cement (OPC) in blended cement (BC) concrete has been established in recent years. However, an optimum mix design of BC concrete should not only achieve the targeted mechanical properties but also aim...
Article
This paper evaluates the feasibility of utilising palm oil fuel ash (POFA) and fly ash (FA) as an Ordinary Portland Cement (OPC) replacement in self-compacting concretes (SCC). The level of OPC replacement is up to 40% based on a 540 kg/m³ mix design. All concrete mixtures were restricted to the following consistency parameter; slump flow of 750 ±...
Article
This research identifies the relative humidity effect and the optimum mixing method for Self-Compacting Concrete (SCC) containing OPC mixed with agro-industrial wastes of palm oil fuel ash (POFA) and low calcium based fly ash (FA). The effects of temperature and relative humidity on the fresh state properties were assessed under three conditions; m...
Article
Full-text available
This paper presents an experimental study on the workability and the heat of hydration in Self-compacting concrete (SCC) incorporating agro-industrial waste and blended aggregates. The control mixture contained only Ordinary Portland Cement (OPC) as the binder while the remaining mixtures incorporated binary and ternary cementitious blends of OPC,...
Article
Full-text available
Global warming arising from the release of greenhouse gasses into the atmosphere is one of the biggest issues attracting a lot of attention. One of the conventional problems in sequestration projects is the degradation of Portland cement due to its exposure to supercritical CO2. This paper gives a review on the laboratory work performed to understa...
Article
Full-text available
This research investigates the fresh state properties and hardened state properties of medium strength, self-compacting concrete incorporating a high volume of class F fly ash as a partial replacement to cement and blended fine aggregates while maintaining satisfactory properties of SCC. The properties of self-compaction investigated are: slump flo...
Article
Full-text available
This paper presents the workability properties of Self-Compacting Concrete (SCC) containing a ternary mix binder using Ordinary Portland Cement and agro-industrial wastes i.e; palm oil fuel ash (POFA) and low calcium based fly ash (FA). The mixtures were prepared with 0 to 40% cement replacement using agro-industrial wastes at 10% intervals. Water...
Article
This paper presents an experimental study on the development of normal strength Self compacting concrete (SCC) from uncontrolled burning of rice husk ash (RHA) as a partial replacement to cement and blended fine aggregate whilst maintaining satisfactory properties of SCC. Experiments on the fresh and hardened state properties have been carried out...
Article
Full-text available
The aim of this research is to investigate hardened state properties of Self Compacting Concrete (SCC) containing low calcium based fly ash. The mixtures were prepared using various proportions of Class F fly ash ranging from 0% to 30% cement replacement. Water to powder ratio is 0.38 – 0.39 and powder content was kept constant at 540 kg/m3. Proper...
Conference Paper
Full-text available
This research investigates hardened state properties of Self Compacting Concrete (SCC) containing low calcium based fly ash. The mixtures were prepared using percentages of Class F fly ash ranging from 0% to 30% cement replacement. Water to powder ratio is 0.38 – 0.39 and powder content was kept constant at 540 kg/m3. Properties investigated were s...

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