Antonios Kanellopoulos

University of Hertfordshire | UH · School of Physics Engineering & Computer Science

Hydrophobized soils have functional hydrophobic coatings to delay or restrict water infiltration and thus prevent infrastructure failure and long-term degradation. Over time, hydrophobized soils will be subjected to degradation under the action of external stresses, leading to the loss of its functional properties. Microencapsulation approaches, in...

Self-healing approaches are increasingly being explored in various fields as a potential method to recover damaged material properties. By self-recovering without external intervention, self-healing techniques emerge as a potential solution to arrest or prevent the development of large strains problems in soils (e.g., landslides) and other ground e...

The present study discusses preliminary findings on the potential of upcycling mine tailings into an alternative source of supplementary cementitious materials. Thermal and mechanical activation mechanisms were used to alter the highly crystalline microstructure of the raw tailings. Scanning and transmission electron microscopy and X-ray diffractom...

Soil settlement leads to serviceability issues of ground infrastructure and is a threat to the stability of overlying structures. To recover the soil shear strength, microcapsules-based self-healing materials are proposed. The purpose of this paper is to review the various cementing cargos with a greater potential to be applied in soils. At first,...

Encapsulated rejuvenating agents for self-healing of bituminous materials have gained significant interest within the road scientific community, turning these enhanced materials into a hot topic. In this study, virgin cooking oil, waste cooking oil, and virgin engine oil were used as encapsulated rejuvenators to restore properties of aged bitumen a...

The construction sector offers a potential market for upcycled mine tailings at large scale. The article explores how the mining and construction industries can come together towards a sustainable future built environment.

The importance of materials science and engineering is paramount for developing new materials and components that will support our continuously growing needs as a society. At the same time, preserving our natural habitat by minimising our carbon emissions and waste of natural resources has also gained, quite rightly, significant attention over the...

Self-healing construction materials have caused great interest in the last decade due to their several applications for civil engineering. A self-healing material is defined as an artificial or synthetically created material that has the built-in ability to repair damage to itself without human intervention

Reinforced concrete (RC) is the dominant construction material and the key element in the vast majority of infrastructure assets, which in turn are the backbone of our societal and economic growth. Bridges, highways, air- and seaports, powerplants, water and sewage treatment facilities, hospitals, tunnels are all essential to maintain the modern wa...

The world’s urban population has quadrupled since the 1950s. 4bn people live in cities today, but according to the United Nations this could jump to 7bn by 2050. To accommodate roughly 3bn more people, our civil infrastructure needs to grow and keep pace. Amid a climate crisis, the question is how can we do this in a sustainable way?

Increase in demand for mineral commodities such as coal, copper, iron, aluminium, gold, tungsten, zinc etc., has led to higher quantity of mineral waste produced such as solids, crushed rocks, overburden soil and tailings. The fine-grained mineral waste left after removal of valuable material from ore is called mine tailing and is one of the major...

Structural health monitoring (SHM) using self-sensing cement-based materials has been reported before, where nano-fillers have been incorporated in cementitious matrices as functional sensing elements. A percolation threshold is always required in order for conductive nano-fillers modified concrete to be useful for SHM. Nonetheless, the best pressu...

This book provides a thorough overview of all techniques for producing self-healing construction materials. Construction materials (cement-based, bituminous, metals, and alloys) are prone to cracking, which with the progress of time can lead to compromising of the structural integrity of critical infrastructure. Self-healing materials form a new cl...

The in-plane thermoelastic response of curved beams made of porous materials with different types of functionally graded (FG) porosity is studied in this research contribution. Nonlinear governing equations are derived based on the first-order shear deformation theory along with the nonlinear Green strains. The nonlinear governing equations are sol...

The future sustainable built environment focuses mainly on environmental conservation and technological innovation and development. However, with infrastructure development, the consumption of raw materials such as cement, gypsum, sand, and stones increases. Therefore, use of industrial waste as raw material in construction shall be proposed as a s...

Structural health monitoring (SHM) using self-sensing cement-based materials has been reported before, where nano-fillers have been incorporated in cementitious matrices as functional sensing elements. A percolation threshold is always required in order for conductive nano-fillers modified concrete to be useful for SHM. Nonetheless, the best pressu...

New graphene/polymer nanocomposites were prepared using graphene nanoplatelets (GNPs) and the epoxy system Epilok 60-566/Curamine 32-494. The GNPs were first dispersed into the curamine hardener using bath ultrasonication, followed by the addition of the epoxy resin. The cure kinetics were studied by DSC under non-isothermal and under isothermal co...

New graphene/polymer nanocomposites were prepared using graphene nanoplatelets (GNPs) and the epoxy system Epilok 60–566/Curamine 32–494. The GNPs were first dispersed into the curamine hardener using bath ultrasonication, followed by the addition of the epoxy resin. The cure kinetics were studied by DSC under non-isothermal and under isothermal co...

Near surface mounted (NSM) carbon fibers reinforced polymer (CFRP) reinforcement is one of the techniques for reinforcing masonry structures and is considered to provide significant advantages. This paper is composed of two parts. The first part presents the experimental study of brick masonry walls reinforced with NSM CFRP strips under combined sh...

Research has shown that even self-compacting concrete (SCC) mixtures can exhibit the so-called "top-bar effect" which impacts bond and anchorage. Several instances of conflicting results have nevertheless been published regarding interfacial bond between self-compacting concrete and steel reinforcement. The scope of this paper is to present an expe...

The classification of a concrete mixture as self-compacting (SCC) is performed by a series of empirical characterization tests that have been designed to assess not only the flowability of the mixture but also its segregation resistance and filling abil-ity. The objective of the present work is to correlate the rheological parameters of SCC matrix,...

Maintaining the health and reliability of our infrastructure is of strategic importance. The current state of the UK infrastructure, and the associated huge costs of inspection, maintenance, repair and eventual replacement, is not sustainable and is no longer environmentally viable. The design of infrastructure, mainly concrete, remains traditional...

Using mineral additives and admixtures as self-healing agents in cement-based composites has been extensively researched. However, if the minerals are added directly to the cementitious matrix without any protection, they could immediately react, leading to a decrease in self-healing efficiency with further associated side-effects on the mechanical...

This study investigates the impact of expansive minerals, namely magnesium oxide, bentonite clay, and quicklime on the early age autogenous self-healing capacity of Portland cement (PC) paste. Individual mineral dosage in PC was studied comprehensively together with several multiple mineral combinations. The study also covers a brief state of the a...

Materials for Life (M4L) was a 3 year, EPSRC funded, research project carried out by the Universities of Cardiff, Bath and Cambridge to investigate the development of self-healing cementitious construction materials. This paper describes the UK's first site trial of self-healing concrete, which was the culmination of that project. The trial compris...

This paper investigates the influence of the type and amount of recycled metallic waste on the physical and mechanical properties of cement-based mortars. The physical and mechanical properties of cement mortars, containing four different amounts of metallic waste (ranged 4 to 16% by cement weight), were evaluated by measuring the bulk density, tot...

Microcapsules, with sodium silicate solution as core, were produced using complex coacervation in a double, oil-in-water-in oil, emulsion system. The shell material was a gelatin-acacia gum crosslinked coacervate and the produced microcapsules had diameters ranging from 300 μm to 700 μm. The shell material designed with switchable mechanical proper...

Concrete, a composite material consisting of aggregates bound together with cement paste, is the most widely used construction material. The production of cement alone accounts for a significant amount of global carbon-dioxide emissions and there is a real need to reduce cement consumption whilst creating more durable materials and structures. Curr...

This study investigated a technique of impregnating potential self-healing agents into lightweight aggregates (LWA) and the self-healing performance of concrete mixed with the impregnated LWA. Lightweight aggregates with a diameter range of 4–8 mm were impregnated with a sodium silicate solution as a potential self-healing agent. Concrete specimens...

Spherical polymeric microcapsules, carrying liquid sodium silicate, were used for autonomic self-healing of mortars. Microcapsules were added at varying volume fractions (Vf), with respect to the cement volume, from as low as 4% up to 32% and their effect on fresh, mechanical and self-healing properties was investigated. For this purpose a series o...

2016 The Author(s)This study investigated a technique of impregnating potential self-healing agents into lightweight aggregates (LWA) and the self-healing performance of concrete mixed with the impregnated LWA. Lightweight aggregates with a diameter range of 4–8 mm were impregnated with a sodium silicate solution as a potential self-healing agent....

This study presents the application of encapsulated expansive powder minerals (magnesium oxide, bentonite and quicklime) for self-healing of cement-based mortars. A system of concentric glass macrocapsules was used to envelope the expansive minerals (outer capsule) and water (inner capsule). Mortar samples containing concentric macrocapsules with d...

Self-healing is inherent in cementitious materials such as concrete. This is largely caused by the continued hydration of cement as well as the formation of calcium carbonate. This autogenic self-healing can be improved through the addition of microencapsulated silica minerals that disperse throughout the cementitious matrix. When cracks propagate...

Cement-based materials possess inherent autogenous self-healing capability allowing them to seal, and potentially heal, microcracks. This can be improved through the addition of microencapsulated healing agents for autonomic self-healing. The fundamental principle of this self-healing mechanism is that when cracks propagate in the cementitious matr...

The Materials for Life (M4L) project team have developed multi‐scale self-healing systems for cementitious materials using a range of interdisciplinary technologies. The three-year EPSRC funded project, which began in July 2013, is a collaboration between Cardiff University, University of Cambridge and University of Bath. The project has investigat...

This study presents the application of encapsulated expansive powder minerals (magnesium oxide, bentonite and quicklime) for self-healing of cement-based mortars. A system of concentric glass macrocapsules was used to envelope the expansive minerals (outer capsule) and water (inner capsule). Mortar samples containing concentric macrocapsules with d...

Several different healing agents and mechanisms have been put forward for use in autonomous healing of small cracks in cementitious composites. While the existing research on this topic focuses mainly on the use of polymeric materials as encapsulated healing agents, this study aims at assessing the efficiency of inorganic silica precursors as poten...

A specification that defines required results, criteria by which performance will be judged, and methods of evaluation, without requirements for how the results are to be obtained.

Spherical polymeric microcapsules, carrying liquid sodium silicate, were used for autonomic self-healing of mortars. Microcapsules were added at varying volume fractions (V$_f$), with respect to the cement volume, from as low as 4% up to 32% and their effect on fresh, mechanical and self-healing properties was investigated. For this purpose a serie...

This study presents the encapsulation of mineral compounds as healing materials for cement-based composites. Three liquid (sodium silicate, colloidal silica and tetraethyl orthosilicate) and one powdered (magnesium oxide) minerals were encapsulated in thin walled soda glass capsules. Load regain was obtained for samples healed under three different...

This study presents the encapsulation of mineral compounds as healing materials for cement-based composites. Three liquid (sodium silicate, colloidal silica and tetraethyl orthosilicate) and one powdered (magnesium oxide) minerals were encapsulated in thin walled soda glass capsules. Load regain was obtained for samples healed under three different...

Capsule based self-healing is an effective method to obtain autonomic healing in concrete, releasing healing agent to seal cracks and in some cases, obtaining partial regain in mechanical properties. Currently, the production of microcapsules containing liquid healing agent is achieved via emulsification and interfacial polymerization, even though...

The Materials for Life (M4L)[1] project team are developing a multi‐scale system using a range of interdisciplinary technologies to promote and enable self‐healing in cementitious materials. The three-year UK Research Council funded project, which began in July 2013, is a collaboration between Cardiff University, University of Cambridge and Univers...

An intrinsic self-sustained recovery system is proposed based on the inclusion of repair agents within a concrete matrix. Three different microencapsulation protocols for the encapsulation of an acrylic-based repair material are being investigated. Polyurethane (PU), urea-formaldehyde (UF) and tetraethylorthosilicate (TEOS) based shell microcapsule...

The research work focused on the determination of guidelines for the production of an UHPFRCC, and the experimental investigation of the mechanical properties of the produced material. The aim of the specific study is to present the results of an extended work on the development of an UHPFRCC with the use of materials available in Cyprus. The funda...

One of the major advances in concrete technology in the last twenty years has been the development of self-compacting concrete (SCC). SCC is characterised by high level of flow and it has the ability to fill formworks and consolidate under its own weight. In its fresh state, SCC consists of a continuously changing dispersion of cement paste and agg...

The present study aims to compare steel-to-concrete bond properties of Self-Compacting Concrete (SCC) mixtures, produced in two laboratories of the European Union (EU) on the basis of similar compositions incorporating silica fume. The similarity of the reference mixtures, in terms of bond, has been achieved by comparing the bond behavior between m...

The demand for improved properties of the construction materials increase with time and the related design and construction codes are adapted in an analogous manner. UHPFRCCs represent a class of cement composites which have superior characteristics in terms of material properties. Their mechanical and fracture behaviour is substantially enhanced c...

The present study intends to evaluate the sensitivity of self-compacting concrete (SCC) mixtures, cast in two different laboratories of the European Union, with a focus on rheological parameters, mechanical characteristics and durability properties. Six SCC mixtures with different water-to-binder ratios and silica fume levels of cement replacement...

Although self compacting concrete (SCC) is currently used in many countries, there is a fundamental lack of the intrinsic durability of the material itself. This article presents the outcomes from a research program on principal indicators that define the durability of SCC (sorptivity, porosity and chloride ion permeability) and compares these indi...

The research work focused on the determination of guidelines for the production of an UHPFRCC, and the experimental investigation of the quality and the behaviour of this material in a highly demanding application, such as the impact resistance of structures. Specifically, the aim of this study is to present the results of an extended work on the d...

Self Compacting Concrete (SCC) offers a wide variety of advantages during casting. Considering the worldwide uniformity of guidelines concerning the composition and casting instructions for the production of fresh SCC, there is a need to explore the reproducibility of similar self-compacting concrete batches between different countries. In the pres...

The aim of the specific study is to present the results of an extended work on the development of an UHPFRCC with the use of materials available in Cyprus. The fundamental idea for the development of this high performance material is the enhancement of the microstructure of the final product. The incorporation in the mix of extremely fine, pozzolan...

Research has shown that high slump concrete mixtures can exhibit bond problems especially at the top-cast bars due to blocking of bleed water underneath the reinforcement. As far as self-consolidating concrete is concerned there are many conflicting results in the literature regarding its bond to reinforcement. The scope of this paper is to present...

The true specific fracture energy of any type of concrete G F is the most useful material parameter in the analysis of cracked concrete structures. It has been observed that a size-independent specific fracture energy G F of concrete could be obtained by testing very few three point bend (TPB) or wedge splitting (WS) specimens of the same dimension...

A series of tests on filigree slab joints was performed with the aim of assessing whether such joints can be reliably used in the construction of two-way spanning reinforced concrete slabs. The test results were compared with code requirements. Adequate joint performance is shown to be achievable when the joints are appropriately detailed. Further...

A class of ultra-high-performance fibre-reinforced cementitious composites (UHPFRCC) has been developed at Cardiff university and registered under the trade name CARDIFRC. The method of its production and its mechanical and fracture properties were reported previously in a series of papers in Magazine of Concrete Research. Here the results of recen...

This study investigates the effect of thermal cycling on the performance of concrete beams retrofitted with CARDIFRC, a new class of high performance fiber-reinforced cement-based material that is compatible with concrete. Twenty four beams were subjected to 24 h thermal cycles between 25 and 90°C. One third of the beams were reinforced either in f...

The fundamental principle behind the development of SCC has been the nanoscale tailoring of cementitious matrices. Although self-compacting concrete (SCC) is currently used in many countries, there is a fundamental lack of the intrinsic durability of the material itself. The scope of the current paper is to present the outcomes of a research study...