Andrzej Cwirzen

• Professor
• Professor (Full) at Luleå University of Technology

Carpet fibres have demonstrated the potential to mitigate early-age cracking and improve tensile properties in concrete. However, a detailed analysis of the varied types of standard carpet fibres in reinforced concrete has been lacking. This study aims to bridge this gap by investigating the performance of concrete reinforced with widely used waste...

The growing demand for renewable energy has increased the use of offshore wind turbines, requiring sturdy infrastructure. However, environmental challenges impact not only the turbine components but also the foundations in the water. Different foundation structures exist for varying sea-bed conditions, each with material durability pros and cons. C...

Mortar sensors were fabricated as beams incorporating different amounts of carbon nanofibers (CNFs) synthesized in-situ on cement particles. Changes in electrical resistivity were measured and compared to recorded changes in compressive stress, temperature, and humidity. Sensing mechanisms and corresponding models were developed. The findings of...

Brash ice formation and accumulation occur at a faster rate in ship channels, harbours and turning areas compared to the surrounding level ice. Accurate prediction of brash ice thickness plays an important role in addressing operational challenges and optimisation of ice management strategies. This study enhances existing brash ice growth models by...

Mortar beams incorporating carbon nano-fibers (CNFs), which were synthesized in situ on Portland cement particles, were used to produce nanomodified Portland cement sensors (SmartCem sensors). SmartCem sensors exhibited an electrical response comparable to a thermistor with a temperature coefficient of resistivity of-0.0152/°C. The highest temperat...

Merchant vessels’ performance on brash ice plays an important role in navigation in fast ice conditions in Northern Baltic ports. Among many parameters, the piece size distribution and macroporosity of the brash ice influence the accuracy of the model simulations of ship performance in brash ice. These properties also govern the brash ice accumu...

This study determined how replacing sodium nitrate-based antifreeze admixture (AF) with belite-calcium sulfoaluminate (belite-CSA) cement affects the early age properties of ecological concretes based on ordinary Portland cement (OPC) and ground granulated blast-furnace slag (GGBFS). Concrete specimens were cured at −15 °C and treated in various wa...

Snow ice (SI) forms from freezing wet snow, known as slush, and contributes to the thickness of level and brash ice. However, the mechanism of snow-slush-snow ice transformation has not been extensively investigated to date, despite the difference in the freezing rate of slush in comparison with water is important for estimating the ice thickness....

Cement production contributes significantly to carbon dioxide emissions. Alkali-activated materials offer an environmentally friendly alternative due to their comparable strength, durability and low-carbon emissions while utilizing wastes and industrial by-products. Wood ash is a waste material that shows promising results as a partial replacement...

Brash ice forms when vessels navigate in level ice breaking it, and subsequently along the same track breaking the partly or fully consolidated broken ice field. The formation and growth of brash ice can be rapid and present a hazard for shipping operations, often requiring icebreaker assistance. Compared to other deformed ice structures such as pr...

The prediction of formwork pressure exerted by self-compacting concrete (SCC) remains a challenge not only to researchers but also to engineers and contractors on the construction site. This article aims to utilize shallow neural networks (SNN) and deep neural networks (DNN) using Long Short-Term Memory (LSTM) approach to develop a prediction model...

The thickness and properties of brash ice are usually compared with the properties of the surrounding level ice. The differences between these ice types are important to understand since the consolidated brash ice layer is typically assumed to have the same properties as level ice. Therefore, significant effort in the measurement campaign during th...

The concrete, which is the most common material used after water, is associated with emissions of large amounts of CO2 related to the Portland cement which is responsible for a total 5–8% of the global CO2. The manufacture of hybrid concrete elements allows the use of the cement to be optimized and minimized by replacing it with secondary cementiti...

Concrete technology is becoming more and more sustainable and ecological following more extensive and focused research. The usage of industrial waste and by-products, such as steel ground granulated blast-furnace slag (GGBFS), mine tailing, fly ash, and recycled fibers, is a very important step toward a good transition of concrete into a “green” fu...

Autogenous self-healing of post-fire damaged concrete enables structure performance auto-recovery leading to reduced repair costs, less generated waste, and lower CO2 emissions. In this paper, to improve the efficiency of this process and understand the underlying mechanism, the self-healing of 0.1 wt% MWCNT-modified and pure cement paste subjected...

Different ecological binders have been used to minimize the negative effects of cement production and use on the environment. Wood ash is one of these alternative binders, and there has been increasing research related to this topic recently. The wood ash utilized in the literature primarily originates from power plants and local bakeries, and pred...

Concrete is one of the most common building materials in the Northern Periphery and Arctic, and therefore we should pay attention to its quality while reducing its carbon footprint. The concrete industry has established many measures to limit greenhouse gas emissions from concrete, as stated in the environmental product declaration (EPD). The most...

Developing accurate and interpretable models to forecast concrete’s self-healing behavior is of interest to material engineers, scientists, and civil engineering contractors. Machine learning (ML) and artificial intelligence are powerful tools that allow constructing high-precision predictions, yet often considered “black box” methods due to their...

Despite the advantageous benefits offered by self-compacting concrete, its uses are still limited due to the high pressure exerted on the formwork. Different parameters, such as those related to concrete mix design, the properties of newly poured concrete, and placement method, have an impact on form pressure. The question remains unanswered on the...

Structural health monitoring (SHM) of road pavements is an essential task, which can help the decision-making process for timely maintenance actions. Embedded sensors are typically used to collect long-term monitoring data. However, the main drawbacks of intrusive sensors concern the risk of premature damage and the incompatibility of the sensors w...

This manuscript presents preliminary results on the cement paste potential, with and without carbon nanomaterials, to heal high-temperature cracks. Cement paste beams were subjected to thermal loading of 200°C and 400°C after 28 days of water curing. High temperature caused the formation of microcrack networks on the specimen’s surface. Self-healin...

The effects of a partial replacement of Ordinary Portland cement (OPC) with three types of calcium sulfoaluminate (CSA) cements (40 wt% and 20 wt%) were investigated. The obtained results were generally in agreement with previously published data but with few interesting exceptions. Setting times were shortened due to the formation of ettringite. T...

Concrete structures exposed to harsh environments, especially including bridges, harbor structures are often suffered from durability problems. Typical external signs include surface deterioration, cracking caused by for example sulphate attack, frost action or reinforcement corrosion. All are strongly linked to the porous microstructure of the bin...

The manufacture of elements containing two types of concrete allows for the minimization of the amount of Portland cement by matching the properties of concrete with local structural and durability requirements. The most common production method of the hybrid element is wet-on-hard and wet-on-wet. Casting wet-on-dry is the most common approach whil...

Replacement of cement with supplementary cementitious materials (SCMs) is a proven method to reduce clinker in cement and contribute to decreased CO2 emissions. Natural clays are commonly occurring materials that do not possess pozzolanic activity in their original state. Mechanochemical activation (MCA) can be an alternative and sustainable method...

Self-sensing road pavements can autonomously monitor their stress/strain and damage states without the need for embedded sensors. This kind of multifunctional pavements could be used for the realisation of autonomous structural health monitoring (SHM) systems. Moreover, it would permit to collect important traffic data for traffic-monitoring analys...

A large-scale shear apparatus has been originally developed and built to test the mechanical properties of coarse-grained material. It was used to evaluate the shear behaviour of brash ice. The brash ice blocks were collected at Luleå harbour in two separate measuring campaigns in March 2020 and March 2021. The shear cylinder was loaded with brash...

Lowering the freezing temperature of the mixing water is crucial for concrete works at subzero temperatures. In this study, formation of ice was examined for various pastes and concretes of OPC-GGBS based, while exposed to a constant temperature of −15 °C. Sodium nitrate antifreeze admixture was added as 0, 6, 10, 15, 20, 25, 30 wt% by the total bi...

Digital transformation of concrete technology is one of the current "hot topics" tackled by both academia and industry. The final goal is to fully integrate the already existing advanced concrete technologies with novel sensors, virtual reality, or Internet of things to create self-learning and highly automated platforms controlling design, product...

Frequent navigation in ice-infested waters causes brash ice formation and accelerated ice growth. Large ice accumulation in ports and vessel tracks can hamper maritime activities. Therefore, the forecast of brash ice occurrence requires accurate prediction models based on frequent and comprehensive observations and measurements. However, field and...

Brash ice forms in harbours and ship channels from frequent ship passages and the resulting freezing–breaking cycles create a unique ice formation. The brash ice accumulation over the winter season is a result of meteorological, thermodynamical and mechanical processes. A reliable brash ice growth model is an important asset when determining naviga...

Cement paste is the matrix of one of the most widely used building material in the world, i.e., concrete. Cement production is estimated to account for 8% of global CO2 emissions. Thus, the impact of cement composites on the environment is enormous. Scientists are conducting research to reduce this negative environmental effect by using materials w...

The production of ordinary Portland cement is associated with significant CO2 emissions. To limit these emissions, new binders are needed that can be efficiently substituted for cement. Alkali-activated slag composites are one such possible binder solution. The research programme presented herein focused on the creation of alkali-activated slag com...

The maximum amount of lateral formwork pressure exerted by self-compacting concrete is essential to design a technically correct, cost-effective, safe, and robust formwork. A common practice of designing formwork is primarily based on using the hydrostatic pressure. However, several studies have proven that the maximum pressure is lower, thus poten...

This book focuses on the application of carbon nanotubes and carbon nanofibers in traditional concretes based on Portland cement. Fundamental information is given related to the production technologies of carbon nanotubes and carbon nanofibers, as well as concretes and methods of incorporation. It also contains a section focusing on the possible ne...

Commonly used humidity sensors are based on metal oxides, polymers or carbon. Their sensing accuracy often deteriorates with time, especially when exposed to higher temperatures or very high humidity. An alternative solution based on the utilization of Portland cement-based mortars containing in-situ grown carbon nanofibers (CNFs) was evaluated in...

An attempt has been made to predict the ice rubble field load on Norströmsgrund lighthouse by using Cohesive Element (CE) formulation. Two sub-load events were selected to validate the numerical and material model used in simulation of interaction of the ice rubble field and lighthouse. A literature review of simulation of rubble field structure in...

The repeated passage of ships through ice-infested waters create a field of broken ice pieces. The typical size of the broken ice pieces is generally <2.0 m. This area might be referred to as a brash ice field. The movement of ships and vessels leads to the transportation and accumulation of broken ice pieces in a brash ice field. A better understa...

The construction of the future is moving in the direction of environmentally friendly materials and the use of various types of industrial byproducts and wastes. The use of blast furnace slag (BFS) for the production of concrete is one of those alternatives. In this study, pastes and concretes based on high-MgO BFS were alkali activated with 10% by...

The deposition of textile waste into landfill has reached an unsustainable level and raises serious environmental issues across the world. Transforming textile waste into fiber reinforcement in cementitious composites offers a sustainable resolution toward a circular textile economy. This article presents a comprehensive review of environmental con...

Drying shrinkage deformation due to moisture migration is a major concern in cementitious materials and can lead to a high probability of cracking, resulting in a deterioration in long-term performance and serviceability. In this paper, the primary mechanisms of drying shrinkage, mitigation strategies and the research gaps are elucidated to provide...

The global nanomaterials market, including carbon nanotubes (CNTs) and carbon nanofibers (CNFs), has drastically grown over the last few decades, and continues to attract attention from numerous industries, including the construction sector. However, their fiber-like character triggers a comparison to a well-known carcinogen: asbestos. Concrete mat...

The majority of new structures are built at least partially of concrete, a material that was developed centuries ago but only became widely used with the invention of Portland cement in the early 1800s. Sadly, concrete is often perceived as a boring gray material that is not environmentally friendly or durable. However, intensive research and devel...

Concrete has been used as a shielding material against various types of radiation for a number of decades. The production technology of concrete enables the incorporation of various types of fillers, fibers or aggregates, which can enhance its shielding properties against specific types of radiation. Typically, heavy weight fillers and aggregates,...

Global warming has triggered an intensive search for alternative sources of green energy. Wind, solar, and hydropower are already commonly used in many parts of the world. Because of the latest developments in science and technology, we are able to harvest energy from some unlikely sources, including temperature gradients, strains developing within...

Noncarbon-based nanomaterials are commonly used in a number of industrial applications, biopharmaceutical products, and in medicine. Building materials, including concrete, also use some of these nanomaterials extensively in full-scale applications. Their effects on concrete rheology, hydration processes, mechanical properties, and durability depen...

Carbon is a minor element found in the Earth’s crust, but is the basis for many compounds and materials found on this planet. From an engineering perspective, diamond, graphite, fullerenes, amorphous carbon, carbon nanotubes, carbon nanobuds, and carbon nanofibers, are the most important of the carbon-based materials. Applications of these carbon a...

The majority of sensors currently used are based on metallic components, and are usually fixed to the external surface of the concrete element or structure they are monitoring. The durability and reliability of these solutions is very low, while costs tend to be very high. The optimum solution would be to produce a concrete capable of self-monitori...

Concrete is one of the few construction materials, which has the ability to be produced directly on the building site. It is also based predominantly on locally available resources, for example, fine and coarse aggregates, and water. This often helps save on transportation time and costs, which, in the case of large structures, that is, water dams,...

Alternative cementious binders have been used in concretes for many decades. Many of them are based on industrial byproducts, which are often considered as having a zero-carbon footprint. Fly ash and blast furnace slag are certainly the most well-known examples. They can be used either as a partial or full replacement of Portland cement in normal c...

Concrete manufacturing is characterized by the production of large amounts of material, that is later transported to a building site, placed, and cured. Carbon nanotubes (CNTs) and carbon nanofibers (CNFs) can be added to concrete mixes, either as dry powders, or wet dispersions. Many production technologies remain rather primitive, and unfortunate...

Carbon nanotubes and carbon nanofibers are still relatively novel nanomaterials, with the first documented discovery dating back to the end of the 20th century. Both materials are known for their excellent physical and mechanical properties, and because of this, are attractive to various industries. The scope of current and potential future applica...

Carbon nanotubes and carbon nanofibers are relatively new materials, whose use has steadily increased in various applications over the past few decades. The electronic and pharmaceutical industries are currently the main players, but the construction industry, especially the mass production of concrete, is following closely behind. Concrete is an e...

A reduced carbon footprint and longer service life of structures are major aspects of circular economy with respect to civil engineering. The aim of the research was to evaluate the interfacial bond properties between a deteriorated normal strength concrete structure and a thin overlay made of Eco-UHPC containing 50 wt% of limestone filler. Two typ...

Winter navigation in the North Sea is expanding with respect to vessel size and traffic volume. Icebreakers create routes for ice-going vessels by breaking the level ice cover. Repeated vessel passages in the fairways and harbors initiate the formation of brash ice. The brash ice has the ability to refreeze quickly. In the current work, a field stu...

A nanomodified cement consisting of particles with in situ synthesized carbon nanofibers was developed to introduce a strong load-sensing capability of the hydrated binder matrix. The material was produced using chemical vapor deposition. The nanomodified cement contained 2.71 wt% of carbon nanofibers (CNFs). The electrical properties of the compos...

This research studies the effect of retarder, accelerator, stabilizer, air-entraining agent, and shrinkage-reducing admixture (SRA) on plastic shrinkage cracking in self-consolidating concrete (SCC). The main objective is to identify the dominant cracking cause-that is, plastic settlement or plastic shrinkage-in an SCC containing a particular admix...

This paper investigates and compares the effect of steel fibres obtained through recycling waste tyres (known as RTSF), and a commercially available hooked steel fibre (HSF), on plastic shrinkage cracking in self-compacting concrete. The volumetric deformations of the specimens, bleeding, and the mass loss have been quantified. Mixtures containing...

Most of the currently used concretes are based on ordinary Portland cement (OPC) which results in a high carbon dioxide footprint and thus has a negative environmental impact. Replacing OPCs, partially or fully by ecological binders, i.e., supplementary cementitious materials (SCMs) or alternative binders, aims to decrease the carbon dioxide footpr...

An efficient solution to increase the sustainability of building materials is to replace Portland cement with alkali-activated materials (AAM). Precursors for those systems are often based on water-cooled ground granulated blast furnace slags (GGBFS). Quenching of blast furnace slag can be done also by air but in that case, the final product is cry...

Exposure conditions are critical for the autogenous self-healing process of Portland cement based binder matrixes. However, there is still a significant lack of fundamental knowledge related to this factor. The aim of this paper was to investigate and understand the effects of various potentially applicable curing solutions on the efficiency of the...

Exposure conditions are critical for the autogenous self-healing process of Portland cement based binder matrixes. However, there is still a significant lack of fundamental knowledge related to this factor. The aim of this paper was to investigate and understand the effects of various potentially applicable curing solutions on the efficiency of the...

This study aimed to determine the effects of curing regime on shrinkage of alkali-activated concretes produced from a Swedish high-MgO blast furnace slag. Sodium carbonate (SC), sodium silicate (SS), and their combination were used as alkali activators. The studied curing procedure included heat-treatment, no heat-treatment, sealed and non-sealed c...

This study aimed to determine the effects of curing regime on shrinkage of alkali-activated concretes produced from a Swedish high-MgO blast furnace slag. Sodium carbonate (SC), sodium silicate (SS), and their combination were used as alkali activators. The studied curing procedure included heat-treatment, no heat-treatment, sealed and non-sealed c...

Mechanical activation in a planetary ball mill (BM) is an environmentally friendly process able to enhance the chemical and pozzolanic activity of natural clays. Those materials can be used as supplementary cementitious materials (SCMs) to partially replace Portland cement in concrete. The process parameters of the BM are directly related to the de...

Alkali-activated slag (AAS) based materials is one the alternative cementitious binders enabling to reduce CO2 footprint of concrete. In general, AAS concretes have good mechanical properties and excellent durability but suffer from very high drying shrinkage, which can be up to six times higher than observed in Portland cement based concretes. In...

The Arctic region is receiving an increasing attention due to the diminishing area of the permanent ice and easing access to various natural resources including especially oil, gas and rare metals. The nearest future will require building a significant number of new harbors and other structures related to sea operations and exploration. Harsh weath...

Ultra high performance concrete (UHPC) is self-compacting, reaching compressive strength over 200 MPa and flexural strength exceeding 30 MPa material. The used very low W/C ratio and high amount of Portland cement often exceeding 900 kg/m3, addition of up to 30% of silica fume produces a very dense and nearly impermeable binder matrix. In this rese...

A cement-based matrix incorporating conductive materials such as carbon nanotubes and carbon nanofibers can have self-sensing capability. Both nanomaterials are characterized by excellent physical, mechanical and electrical properties. A disadvantage is that due to their hydrophobic nature it is very difficult to ensure uniform dispersion throughou...

Waste management is emerging as one of the most troublesome and critical problems of the upcoming decades. Therefore, the utilization of industrial by-products as building materials components has been widely studied in recent years. Geopolymer concrete, with binder entirely substituted by slag or fly ash, is one of the materials, which combines po...

Plastic shrinkage cracking in concrete is mainly a physical process, in which chemical reactions between cement and water do not play a decisive role. It is commonly believed that rapid and excessive moisture loss, due to evaporation is the primary cause of the phenomenon. Once the concrete is cast, its solid particles start to settle due to gravit...

Plastic shrinkage cracking in concrete is mainly a physical process, in which chemical reactions between cement and water do not play a decisive role. It is commonly believed that rapid and excessive moisture loss due to evaporation is the primary cause of the phenomenon. This paper presents a new model to estimate the severity of plastic shrinkage...

The effects of fines and chemical composition of three types of ground granulated blast furnace slag (GGBFS) on various concrete properties were studied. Those studied were alkali activated by liquid sodium silicate (SS) and sodium carbonate (SC). Flowability, setting times, compressive strength, efflorescence, and carbonation resistance and shrink...

The effects of fines and chemical composition of three types of ground granulated blast furnace slag (GGBFS) on various concrete properties were studied. Those studied were alkali activated by liquid sodium silicate (SS) and sodium carbonate (SC). Flowability, setting times, compressive strength, efflorescence, and carbonation resistance and shrink...

It is commonly accepted that the autogenous self-healing of concrete is mainly controlled by the hydration of Portland cement and its extent depends on the availability of anhydrous particles. High-performance (HPCs) and ultra-high performance concretes (UHPCs) incorporating very high amounts of cement and having a low water-to-cement ratio reach t...

Self-healing can be defined as the ability of a material to repair inner damage without any external intervention. In the case of concrete, the process can be autogenous, based on optimized mix composition, or autonomous, when using additionally incorporated capsules containing a healing agent and/or bacteria spores. The first process uses unhydrat...

First-year ice ridges are one of the main load scenarios that off-shore structures and vessels operating in ice-covered waters have to be designed for. For simulating such load scenarios, the knowledge gap on ice mechanical properties from the consolidated part of first-year ridges has to be filled. In total 410 small-scale uniaxial compression tes...

Concrete, a well-established and well-characterized building material, is also the most used building material in the world. However, many old and new-build structures suffer from premature failures due to extensive deterioration and decreased load-bearing capacity. Consequently, structural monitoring systems are essential to ensure safe usage of c...

Mechanochemical activation can be defined as a process able to induce structural disorder through intensive grinding. In certain conditions, it may increase the chemical reactivity of the processed material. The process is extensively utilized in extractive metallurgy, synthesis of nanocomposites or pharmacology. It is also considered an environmen...

This research investigates the effect of capillary pressure and the length of the hydration dormant period on the plastic shrinkage cracking tendency of SCC by studying specimens produced with different w/c ratios, cement types and SP dosages. A relationship between the capillary pressure rate and the length of the hydration dormant period is defin...

Mortar and concrete can be divided into two phases of solids and water, where water fills the voids between the grains and also coats the surface of the particles. The current study investigates the influence of the thickness of coating water on flow spread of mortars and concrete. The article aims at correlating consistency of concrete to consiste...

Deformations of alkali-activated slag concrete (AASC) with high MgO and Al 2 O 3 content, subjected to variable curing temperature were studied. Sodium silicate and sodium carbonate were used as alkali activators. The obtained results showed development of deformations consisting of both shrinkage and expansion. Shrinkage appeared not to be affecte...

Deformations of alkali-activated slag concrete (AASC) with high MgO and Al 2 O 3 content, subjected to variable curing temperature were studied. Sodium silicate and sodium carbonate were used as alkali activators. e obtained results showed development of deformations consisting of both shrinkage and expansion. Shrinkage appeared not to be affected...

Carbon nanofibers (CNFs) were directly synthesized on Portland cement particles by chemical vapor deposition. The so-produced cements contained between 2.51–2.71 wt% of CNFs; depending on the production batch. Several mortar mixes containing between 0 and 10 wt% of the modified cement were produced and the electrical properties at various ages and...

Mortars can be studied as mixtures of solid and flowable phases. The volume of the flowable phase required for deformation depends on the solid phase surface area according to excess layer theories. This paper examines the relation between the specific surface area of constituents in mortars and their flow. The flowable phase volume was divided by...