Seyed Hamidreza Ghaffar

• CEng FICE, PhD, Civil Eng. Material Sci.
• Professor (Associate) at Brunel University London

The weak mechanical properties the 3D printed parts can limit the competence of this technology when compared to conventionally cast-in-mold cementitious composites structures. However, experimental results in this study showed that the incorporation of nano additives could improve the mechanical property of printed structures. Six geopolymeric mix...

Additive manufacturing (AM) of construction materials has been one of the emerging advanced technologies that aim to minimise the supply chain in the construction industry through autonomous production of building components directly from digital models without human intervention and complicated formworks. However, technical challenges needs to be...

The growing demand for sustainable and high-performance asphalt binders has prompted the exploration of waste-derived modifiers. This study investigates the performance enhancement of Natural Asphalt (NA) using Sugarcane Molasses (SM) and Waste Engine Oil (WEO). The modified blends were prepared by partially replacing 50% NA with varying proportion...

The construction industry in Kuwait is experiencing a transformative shift with the adoption of Building Information Modeling (BIM) technologies, particularly BIM 6D for sustainability analysis and 7D for facility management. This study investigates the integration of these dimensions to address sustainability challenges in Kuwait’s construction se...

This research addresses the urgent need for sustainable construction practices by presenting an innovative approach to mitigate the environmental burden associated with Polyvinyl Chloride (PVC) waste disposal. This study offers a dual benefit of waste management and resource conservation by repurposing PVC as aggregates in cementitious systems. The...

The construction industry in Kuwait is experiencing a transformative shift with the adoption of Building Information Modeling (BIM) technologies, particularly BIM 6D for sustainability analysis and 7D for facility management. This study investigates the integration of these dimensions to address sustainability challenges in Kuwait’s construction se...

Robotic construction using 3D concrete printing (3DCP) offers significant potential to transform Kuwait’s construction industry, particularly in reducing waste. This study explores the feasibility of integrating 3DCP into Kuwait's construction waste management practices by examining the perspectives of key stakeholders. Through a mixed method appro...

Waste carbon fibers as reinforcing elements in construction materials have recently gained increasing interest from researchers, providing outstanding strength performance and a lower environmental footprint compared to virgin fibers. Combination with cement-free binders, namely alkali-activated materials, is becoming increasingly important for sus...

Additive manufacturing of low-carbon cementitious composites is becoming increasingly important in the construction sector, offering two-dimensional sustainability from both materials and technology standpoints. To address the pressing demand to lessen the negative consequences of the construction sector on the environment, it is essential to ident...

This study explores the potential of waste brick and geo-cement aggregates as substitutes for natural sand in alkali-activated materials (AAMs) for mortar production. With a focus on achieving net-zero construction and mitigating environmental impact, the study replaces Portland Cement (OPC) and virgin aggregates with waste materials and by-product...

The replacement of virgin aggregate with recycled concrete aggregate (RCA) in concrete mixtures offers an eco-strategy to mitigate the environmental limitations linked with traditional recycling techniques of RCA. However, the inferior properties of RCA, in contrast to virgin aggregate, present an obstacle to efficiently proceeding with this approa...

Construction projects in Kuwait's Ministry of Public Works (MPW) involve numerous resources and stakeholders, necessitating effective communication and data sharing to avoid errors, conflicts, and resource wastage. Integrating Building Information Modelling (BIM) into the traditional procurement management approach has the potential to revolutionis...

This study investigates the printability of one-part brick powder-based alkali-activated materials (AAMs) containing end-of-life brick particles as aggregate. The novel formulation showcases promise for 3D printing of small to medium-sized building blocks, reminiscent of a Lego-type system, capitalising on the rapid setting time inherent to one-par...

Incorporating recycled Unplasticised Polyvinyl Chloride (UPVC) aggregates into Alkali Activated Materials (AAMs) presents a promising approach to alleviate the environmental drawbacks associated with conventional recycling methods for UPVC. The distinctive characteristics of UPVC aggregates, as compared to natural sand, pose a challenge in the purs...

Construction and demolition waste (CDW) poses significant environmental and financial challenges. On-site processing offers benefits such as proper segregation, increased recycling rates, reduced disposal costs, and minimized environmental impact. Off-site sorting practices are more sustainable, alleviate project team burdens, and save space. Howev...

This study set out to examine the unconventional use of raw oil shale (OS) as fine aggregate in concrete instead of its traditional utilisation as a pollutant energy source aiming to hinder the depletion of natural resources. Oil shale particles have been used to replace sand in concrete with 30 wt.-% and 50 wt.-% ratios. Part of the used OS partic...

One-part alkali-activated materials (AAMs) can preserve natural resources and lower embodied carbon of the built environment by accommodating various wastes, industrial by-products, and end-of-life materials in their composition. This study investigates the feasibility of using end-of-life bricks in two physical states, powder and aggregate, to par...

The utilization of waste fibers in the production of reinforced concrete materials offers several advantages, including reducing environmental strain and socio-economic impacts associated with composite waste, as well as enhancing material performance. This study focuses on the development of cementitious mortars using secondary waste carbon fibers...

Additive manufacturing (AM), including 3D printing, has the potential to transform the construction industry. AM allows the construction industry to use complex and innovative geometries to build an object, building block, wall, or frame from a computer model. As such, it has potential opportunities for the construction industry and specific applic...

3D printing is a developing technology that has the ability to use different materials to produce concrete elements with complex shapes. The utilization of geopolymers or alkali-activated materials (AAMs) in 3D printing is receiving significant interest due to the environmental benefits of replacing ordinary Portland cement (OPC). The use of solid...

The rapid development in 3D printing applications requires exploring a sustainable printable mixture to decrease the environmental impact induced by the existing Ordinary Portland Cement (OPC) mixtures and enable 3D printing technology to reach its peak efficiency. The high-volume substitution of OPC with supplementary cementitious materials (SCMs)...

The built environment sector is under increasing pressure to reduce costs while improving environmental quality. This paper examines Kuwait’s current construction and demolition waste (CDW) management policy, highlights the obstacles faced by recycling processes and suggests solutions to enhance waste management practices. Kuwait has only one landf...

There is an increasing trend in research projects and case studies to demonstrate the potential of Additive Manufacturing (AM) with concrete, better known as 3D concrete printing. Like ordinary construction, the latest upgrades on this topic are strongly focused towards improving eco-sustainability in terms of low-carbon materials. Low-carbon binde...

Polyvinyl chloride plastic (PVC) and glass waste have proven to be significant environmental concerns considering their restricted reuse and complicated recycling procedures. Glass and PVC waste materials form a substantial portion of total solid wastes that negatively influence the environment. This study aims to fully replace natural sand with re...

To enhance wheat straw compatibility with the polylactic acid (PLA) matrix, several graphene-based materials (GBMs) derivatives, including graphene nanoplatelets, graphene oxide, and nano graphite particles with a constant fraction of 0.1 wt.-%, were employed for the surface functionalisation of wheat straw. Wheat straw surface quality was assessed...

Due to global environmental concerns related to climate change, the need to improve the service life of structures and infrastructures is imminently urgent. Structural elements typically suffer service life reductions, leading to poor environmental sustainability and high maintenance costs. Graphene oxide nanosheets (GONSs) effectively dispersed in...

3D printing technology can be of crucial importance in the design of sustainable and energy-efficient building envelopes. With this technology, there is the potential to mechanically and thermally optimise the topology of printed walls. Additionally, the printing and infill materials used can be insulating, and thus contributing to the overall redu...

There has been increasing interest in using nanosized fillers in cement-based construction materials to upgrade mechanical properties, durability, and multi-functionality. In this context, graphene oxide (GO) is proved to be an effective candidate, and its interaction with cement can lead to remarkable enhancement in its macro-properties. To guaran...

An in-depth investigation of the incorporation of silane-treated and untreated glass waste in concrete is presented in this research. Coarse and fine aggregates were replaced with glass waste in 30 wt.-% and 50 wt.-% ratios, while glass powder was employed as an additive to concrete with 2 wt.-% and 5 wt.-% ratios. Physical, mechanical, microstruct...

This investigation aims to study the performance of different hybrid binders as environmentally-friendly cementitious soil stabilizers as well as Nanosilica as a reactive powder. Mechanical properties and microstructural analysis in addition to the molecular and mineralogical specifications were investigated to evaluate the performance of stabilize...

This study investigates the effects of natural and calcined halloysite clay minerals (“NH” and “CH”, respectively) on the performance of 3D printed alkali-activated materials (AAMs). Halloysite clay minerals are selected as they are low-cost and abundantly available. At first, different characterisation techniques were employed to characterise the...

One of the ways to achieving net-zero concept in the construction industry is to use alternatives to Portland cement (OPC) and virgin aggregates for concrete manufacturing. Recycled rubber and polyvinyl chloride (PVC) aggregates in conjunction with low-carbon binders can be potentially utilised to substitute natural sand and reduce the negative env...

An eco-friendly pre-treatment coupled with surface functionalisation were developed to enhance the quality of wheat straw particles to be used for development of high-performance polylactic acid (PLA) compressed strawboard. Eco-friendly hybrid pre-treatment (i.e., hot water followed by steam, H+S) and surface functionalisation processes employing a...

The utilisation of biochar, the carbon negative product of pyrolysis, reduces the carbon footprint of the cementitious composites as it possesses the potential to replace the consumption of Portland cement. In a systematic investigation, biochar was used as a partial cement replacement for up to 20 wt% in both cement pastes and mortars. A comprehen...

A new line of research is presented in this study where wick drainage technique was implemented in masonry walls. Three different types of wicks, two lignocellulosic natural materials, namely, sisal and jute, and one synthetic, polypropylene were installed on the external side of the walls with the aim of reducing dampness on their interior structu...

Decarbonizing the construction industry is an important step towards achieving the net-zero goals for many countries. New technologies and materials are extensively investigated and proposed to meet sustainability guidelines imposed by governments. This research develops a novel mix of sustainable pozzolanic cementitious composite ordinary Portland...

Integration of reinforcement in the 3D concrete printing (3DCP) process is a major challenge. As a possible solution, the addition of short synthetic/metallic fibers directly to a fresh mixture before extrusion has been investigated in previous studies. However, the use of natural/inorganic microfibers such as wollastonite as reinforcement for 3DCP...

Utilising wheat straw reinforced OPC-free composites in the construction industry requires efficient, eco-friendly pre-treatment coupled with surface functionalisation methods to turn it into a high-performance material. Herein, alkali-activated material (AAM) was used as an OPC-free matrix, while eco-friendly hybrid pre-treatment and surface funct...

The cities are growing dramatically, while adding to the climate challenges. The construction industry has been criticised for generating high volumes of waste and obstructing Sustainable Development Goal (SDGs) targets. The UN Climate Change Conference in Glasgow (COP26) conveyed together 120 world leaders where the Paris Agreement goal of limitin...

This chapter briefly presents an introduction to key technological innovations in construction and their potential/current uses in the industry. Some of these technologies have been written about extensively; however, the summaries presented below are provided as a convenient introduction and reference for subsequent chapters.

This chapter defines circular construction, and how the construction industry should prepare and make interventions to promote the transition from a linear model to circular and sustainable ways of designing, constructing, maintaining and dealing with waste. Circular construction is an emerging business strategy that promotes the reuse and recyclin...

A new line of research is reported in this study where magnetite is used as a partial replacement of traditional aggregates in stone mastic asphalt (SMA) mixtures. The objective is to enhance the functional and mechanical properties of SMA while taking advantage of better thermal properties of magnetite to promote self-healing characteristics of th...

The impact of extra-low dosage (0.01% by weight of cement) Graphene Oxide (GO) on the properties of fresh and hardened nanocomposites was assessed. The use of a minimum amount of 2-D nanofiller would minimize costs and sustainability issues, therefore encouraging the market uptake of nanoengineered cement-based materials. GO was characterized by X-...

Low carbon or near-zero carbon concrete technology is in line with the pillars of sustainable development, where industrial waste or low-carbon binders can reduce or eliminate consumption of Portland cement and natural resources, leading to less environmental pollution. This work presents an experimental study on the comparison between alkali-activ...

Portland Cement Concrete (PCC) pavement was studied with incorporation of an environmentally friendly eco-additive, sodium acetate (C2H3NaO2). This additive was added to PCC pavement in three different percentages of 2%, 4% and 6% of binder weight. For a comprehensive elucidation of the eco-additive incorporation on the performance of PCC pavement,...

Direct Writing (DW), also known as Robocasting, is an extrusion-based layer-by-layer manufacturing technique suitable for manufacturing complex geometries. Different types of materials such as metals, composites, ceramics, biomaterials, and shape memory alloys can be used for DW. The simplicity and cost-efficiency of DW makes it convenient for diff...

One of the fields in the construction industry where 3D printing of cementitious composites can play a significant role is associated with manufacturing of lightweight structures. Thanks to 3D printing, structural self-weight can be reduced by topology optimization of printed elements. Moreover, further decrements of self-weight and improvement of...

This research presents new insights into the utilisation of waste glass powder in concrete pavements. Two different types of glass powder were used as a partial replacement for sand: 10% neat glass powder (untreated) and 10% silane-treated glass powder. The interfacial bonding properties, physical properties, and mechanical properties of concrete p...

It is often claimed that three-dimensional (3D) printing – known in the trade as ‘additive manufacturing’ – will change the way structures and buildings are constructed, from architecturally driven geometric forms to functional, low-cost housing and emergency shelters. Additive manufacturing uses a combination of materials science, architecture and...

The impact of graphite nanoplatelets (GNPs) on the physical and mechanical properties of cementitious nanocomposites was investigated. A market-available premixed mortar was modified with 0.01% by weight of cement of commercial GNPs characterized by two distinctively different aspect ratios. The rheological behavior of the GNP-modified fresh admixt...

Additive manufacturing (AM), also referred as 3D printing, is a technology that enables building automated three-dimensional objects in a layer-by-layer manner. AM of cement-based and alkali-activated composites has gathered attention over the last decade and is one of the most rapidly developing civil engineering fields. Development of proper mixt...

In this paper, the effect of rice husk ash (RHA), as silicate impurities, on the microstructure and mechanical properties of calcium aluminate cement concrete (CACC) is explored. Various mechanical tests, including tests for obtaining the compressive, splitting tensile, flexural strengths and elastic modulus, were performed on different mixture des...

This study investigates the addition of Poly-vinyl Alcohol (PVA) fibres and attapulgite nanoclay to alkali-activated materials (AAMs) with the aim of enhancing the mechanical performance and optimizing the printability and buildability of AAMs. The fresh properties of six mix formulations, including flowability, slump values, rheology, shape retent...

In this study, properties of cement composites and mortars were investigated in presence of Nano-Fe2O3 as their modifier. Cement composites were synthesized using the sol-gel method with tetraethylammonium orthosilicate as the complex legend. Subsequently, Nano-Fe2O3 was added at 2, 4, and 6 wt% dosages to the cement composite, while for mortars 2,...

This article is aimed at investigating the long‐term performance of three original hydrophobic materials, namely, sodium acetate, fluoropolymer, and silicone resin. Their performance was compared with traditional silane when applied to fully dry concrete, fully saturated concrete, and concrete with 2 and 4% moisture content. A recently developed fr...

Individual and hybrid pre-treatments, including hot water, steam and microwave were used on wheat straw to mitigate the surface quality deficiencies for an intimate interfacial bond between substrate and Polylactic Acid matrix. Microstructural analysis showed the expansion of cells due to the pre-treatments which in turn promotes mechanical entangl...

In this study an extensive experimental campaign has been conducted on mortars modified with nano-Graphite (nG) aimed to assess the properties of the resulting nanocomposites in terms of density, microstructure, flexural and compressive strength, damping ratio, thermal and electrical conductivity. Permeability properties were also investigated in t...

The research carried out in this study presents the effectiveness of using sodium acetate as a protective material for concrete pavement. A newly developed freeze-thaw method that depends on the alteration of temperature and humidity is introduced in this research to investigate the efficacy of integrating sodium acetate with concrete with differen...

The widespread popularity of additive manufacturing in most industries ranging from biomedical to aerospace suggests a transformation in manufacturing, which has recently also emerged in the construction sector. This paper presents an active system for the extrusion-based 3D printing of cementitious materials. The system can be extended to other ma...

This study investigates the interfacial bonding of natural fibre reinforced (NFR) cementitious composites by exploring the incorporation of 20-30 mm strands of uncoated and resin coated flax/wool twine into various cementitious matrices. Cementitious matrices consisting of pulverised fly-ash (FA), ground granulated blast furnace slag (GGBS) and ord...

To valorize the naturally abundant biomass, bio-composites made of biomass and functional nano-materials have attracted a great deal of attention. By incorporating alginate with TiO2/RGO nanocomposites, TiO2/RGO/Alginate composite (TRGA) aerogels are fabricated via a facile freeze-drying method. TiO2/RGO nanocomposites can effectively improve the s...

A new line of research is presented in this study where sodium acetate is used as a protective material for concrete. A newly developed freeze-thaw method that depends on the alteration of temperature and humidity is introduced in this research to investigate the efficacy of integrating sodium acetate with concrete with different water to cement ra...

This research presents new insight on the performance of concrete when integrated with sodium acetate and cured under extremely harsh environmental conditions: freezing temperature of -25 °C and hot temperature of 60 °C. Mechanical properties, water absorption, microstructural analysis and interaction mechanism of concrete and sodium acetate were e...

This study justifies strategies for a new concept of agricultural waste management prior to biorefinery, based on comprehensive materials science investigations. Efficient pretreatments for the extraction, separation and fractionation of agricultural waste in conjunction with understanding of the details of its microstructure and properties can be...

The challenges of sustainable construction, industrial growth and importance of resource efficiency are clearly recognised by the UK government and are now at the forefront of strategy and policy. A critical component of the government’s sustainability strategies concerns way in which construction and demolition waste (C&DW) is managed. In this stu...

Additive manufacturing (AM), popularly known as ‘3D printing’, is a manufacturing technique that builds physical 3D objects layer by layer using materials such as polymers, metals, and cementitious composites. The widespread popularity of additive manufacturing in most industries ranging from biomedical to aerospace suggests a revolution in manufac...

It’s often claimed that 3D printing – known in the trade as “additive manufacturing” – will change the way we live. Most recently, a team from Eindhoven University of Technology announced plans to build the “world’s first” habitable 3D printed houses. But it’s one thing to build small, prototype homes in a park – it’s quite another to successfully...

Additive manufacturing (AM), popularly known as ‘3D printing’, is a manufacturing technique that builds physical 3D objects layer by layer using materials such as polymers, metals, and cementitious composites. The widespread popularity of additive manufacturing in most industries ranging from biomedical to aerospace suggests a revolution in manufac...

There has not been extensive research into the subjects of the interfacial bonding quality and the interaction mechanisms of biopolymers and natural fibres. Attempts have been made to incorporate natural fibres/fillers (biofibres) into the manufacture of composites in order to increase the functionality and performance of biopolymers synthesised fr...

Using expanded cork dust as a cheaper substitute of fumed silica, the expanded cork/fumed silica composites with hierarchical porous structure were designed and constructed as an alternative lower cost material for vacuum insulation panel (VIP) core. A novel strategy compromised of microwave pretreatment and vacuum impregnation method is developed...

The interfacial properties with bonding and failure mechanisms of different anatomical sections of wheat straw stem, namely node and internode, inner and outer surface, with various resins are investigated. An environmentally friendly pre-treatment was employed which led to an improved interface between resins and the micro porous surface of straw....

The variation of physicochemical characteristics across wheat straw node and internode with their surface functionalities was investigated. Node yielded slightly higher klason lignin, extractives and ash content than internode, which could be related to their morphology; specifically the higher ash and extractives content in the node are explained...

High global demands for energy, unstable/uncertain petroleum sources and concerns over climate change have led to the resurgence in the development of alternative energy and material sources. Straw biomass conversion processes are attractive because they are in practice today and extension to future scenarios is easy for the public to envision. Alt...

The construction industry has seen an incredibly fast increase in utilizing natural fibres for making low-cost building materials to achieve sustainable construction. One of such applications is natural fibre-reinforced cementitious materials for either structural or non-structural purpose. Impact properties are engineering properties received incr...

i Abstract The demand for the efficient utilisation of straw biomass requires detailed analyses of its fundamental chemical structures, morphological complexity, individual cell wall components and the correlation of physicochemical to mechanical properties. The study involved two main areas: understanding the details of microstructure and characte...

This study is aimed at fully understanding wheat straw by investigating important properties for the processing of wheat straw (node and internode) for further production of bio-composites and bio-fuels as they server as great renewable resource. A combination of mild physical treatments and the synergetic effect of each physical treatment were inv...

a b s t r a c t The relevant information about the lignin in straw and its applications in the industry is scattered and scarce compared to the wood lignin. This review is focused on the chemical structural and composition of lignin in the straw, and its modification and uses as an adhesive. The review has showed that (1) lignin as a by-product in...

The relevant information about the lignin in straw and its applications in the industry is scattered and scarce compared to the wood lignin. This review is focused on the chemical structural and composition of lignin in the straw, and its modification and uses as an adhesive. The review has showed that (1) lignin as a by-product in the pulping proc...

This paper conducted research on fracture and impact properties of short discrete jute fibre reinforced cementitious composites (JFRCC) with various matrix for developing low-cost natural fibre reinforced concretes and mortars for construction. Fracture properties of JFRCC were tested on notched concrete beams at 7, 14 and 28 days and the results w...