Diana Bajare

Diana Bajare
Riga Technical University | RTU · Institute of Materials and Structures

PhD

About

134
Publications
55,726
Reads
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1,902
Citations
Additional affiliations
May 2014 - present
Riga Technical University
Position
  • Professor (Full)
May 2014 - present
Riga Technical University
Position
  • Professor (Full)
September 2006 - May 2014
Riga Technical University
Position
  • Asoc.prof.

Publications

Publications (134)
Article
The waste amount coming from construction and demolition (CDW) has significant volume and potential to provide the backbone of a secondary material bank. Up to now, little attention is paid to waste gypsum recycling from CDW while a shift in global attitude toward waste management brings motivation to use CDW gypsum as secondary raw material. The p...
Article
Full-text available
Hempcrete is a very promising bio-based insulating material with a minor or even negative CO2 footprint and low thermal conductivity. To utilize it efficiently, it must be possible to make predictions regarding hempcrete hygrothermal performance and whether it is up to the modern standards—this requires a verified material model for use in numerica...
Article
Full-text available
European regulations states that the construction industry must encourage the rational and prudent use of non-renewable natural resources, as well as and increase the use of reusable resources and promote the use of renewable natural resources in production. Bio-composites based on natural aggregates such as hemp shives are widely studied and used...
Conference Paper
Hemp concrete is a well-known bio-based building material, but due to its relatively low compressive strength is mainly used as an insulation material with a load-bearing wooden frame. There are possibilities to expand hemp concrete application in construction by substituting traditional lime with magnesium cement. Magnesium oxychloride cement is a...
Article
Full-text available
Carbon dioxide (CO2) emissions associated with Portland cement (PC) production is ranked as the highest among the construction materials and it is estimated that 8% of the worlds CO2 discharges is due to PC production. As an average, the production of PC clinker including calcination process generates 0.81 kg of carbon dioxide per one kg of cement....
Article
Full-text available
According to European regulations, the construction industry supports and strives to save non-renewable natural resources, increases the share of reusable resources in production and attempts to use renewable natural resources as much as possible by creating alternative building materials, such as bio-composites. Various building materials containi...
Article
The present research investigated bio-based construction material based on hemp shives and gypsum. Low-density material was developed with densities of 200, 300, and 400 kg/m³. Simple yet robust production technology was used. For the first time, a binder for biocomposites obtained from phosphogypsum was used and properties were compared to commerc...
Conference Paper
The paper presents a method of calculation of thermal conductivity of bio-based building composites by applying numerical approach which based on the real morphology of sample and the solution of heat conduction equation in the micro-scale. The real microstructure of composite sample was obtained from the X-ray micro tomography (microCT). Then the...
Presentation
Full-text available
Short presentation with videos from our newly founded 3D printing laboratory and printing the first samples of hempcrete with lime binder
Poster
Full-text available
Development of manufacturing technology of novel building products with layered structure and made of ecological fibres high performance composites containing agricultural waste (hemp shives) with improved thermal properties by using microencapsulated phase change materials (PCM). Wall panel made of hemp shives ecological fibre composites. HEMP4NZE...
Article
Full-text available
Self-healing concrete has the potential to optimise traditional design approaches; however, commercial uptake requires the ability to harmonize against standardized frameworks. Within EU SARCOS COST Action, different interlaboratory tests were executed on different self-healing techniques. This paper reports on the evaluation of the effectiveness o...
Article
Full-text available
Amajor problem in the field of adsorbents is that binders (kaolin clay, bentonite) introduced to bind zeolites and ensure the needed mechanical strength, are not able to sorb gases like CO2 and N2, and decrease the overall adsorption capacity. To solve this problem, one of the pathways is to introduce a binder able to sorb such gases. Thus, in this...
Article
Full-text available
Fluid catalytic cracking (FCC) catalysts, used in the petroleum industry, are sources of zeolitic by-products. These by-products are often used as sorbents for the removal of ammonium ions from wastewater. After a period of use, the zeolitic by-product loses its sorption properties and is no longer effective. The problem is the use of zeolitic by-p...
Article
Full-text available
This work is devoted to developing an energy-efficient solution for the external wall and evaluating its environmental impact. Several types of innovative single-layer and sandwich-type wall solutions were analysed and compared. Different constructive and thermal insulation materials were used, including traditional wall materials such as AAC (auto...
Article
Biocomposite building materials with mineral binders are becoming more topical recently because they can address growing environmental concerns regarding carbon footprints and resource depletion better than traditional building materials. However, these new materials also pose new challenges. There have been issues with the compatibility of plant-o...
Article
Full-text available
The construction industry is one of the largest emitters of CO 2 because the production of traditional building materials is highly energy-intensive and uses considerable amounts of raw materials. This research aims to decrease the negative environmental impact of the construction industry by providing biocomposites with a low environmental impact...
Article
Full-text available
Due to the increase of water consumption, water treatment systems become more actual and innovative materials for water treatment are welcomed. Traditionally, alkalizing agents, such as lime or caustic soda, have been employed to increase the pH levels, which induce chemical clarification of wastewater. Some innovative ideas of using low-calcium, a...
Article
Full-text available
This study aimed to determine the impact of the initial temperature of the paste (from 5 °C to 35 °C) and the addition of water, which reflects a decrease in the molarity of activation solutions (AS) by diluting 10 M NaOH with distillate water, on the rheological properties of geopolymer pastes. Additionally, this resulted in changes to the physica...
Article
Alkali activated binders (AAB) are potential alternative to ordinary Portland cement. The AAB is produced by activating the source of amorphous SiO2 and Al2O3 with alkali solutions (NaOH, Na2SiO3·nH2O, KOH or etc.). As a result of alkali activation the N-A-S-H gel is forming as binding phase in the structure. Influence of different SiO2/Na2O ratio...
Article
Full-text available
The potential of phosphogypsum (PG) as secondary raw material in construction industry is high if compared to other raw materials from the point of view of availability, total energy consumption, and CO2 emissions created during material processing. This work investigates a green hydraulic ternary system binder based on waste phosphogypsum (PG) for...
Article
Full-text available
Development and commercialization of self-healing concrete is hampered due to a lack of standardized test methods. Six inter-laboratory testing programs are being executed by the EU COST action SARCOS, each focusing on test methods for a specific self-healing technique. This paper reports on the comparison of tests for mortar and concrete specimens...
Article
Full-text available
Novel mycelium-based biocomposites (MBB) were obtained from local agricultural (hemp shives) and forestry (wood chips) by-products which were bounded together with natural growth of fungal mycelium. As a result, hemp mycocomposites (HMC) and wood mycocomposites (WMC) were manufactured. Mechanical, water absorption and biodegradation properties of M...
Article
Full-text available
The concrete industry is eagerly pursuing the economic advantages of concrete and the improvement of its long-term properties. One of the most effective approaches to improve concrete properties is associated with replacing part of the Portland cement with pozzolanic additives. Although commercial pozzolans like silica fume have proven to be effect...
Article
Full-text available
To decrease the environmental impact of the construction industry, energy-efficient insulation materials with low embodied production energy are needed. Lime-hemp concrete is traditionally recognized as such a material; however, the drawbacks of this type of material are associated with low strength gain, high initial moisture content, and limited...
Poster
Full-text available
Construction is one of the industries with the highest level of CO2 emissions, and it also has a negative effect on other environmental impact categories. This research aims to decrease the negative environmental impact of the construction industry by proposing alternative building materials that have lower environmental impacts due to their bio-ba...
Chapter
Dolomite is the widespread sedimentary rock that finds a wide application in building industry and road engineering. During the treatment of dolomite rocks, a huge amount of fine fractions (0…8 mm) are produced and classified as by-products due to the limited range of applications. For example, nowadays more than 400 000–450 000 t dolomite by-produ...
Article
Full-text available
This work reports and describes a novel alkali-activated metakaolin as a potential binder material for the granulation of zeolites, which are widely used as CO2 adsorbents. The alkali-activated binders are zeolite-like materials, resulting in good material compatibility with zeolite-based adsorbents. A major problem during the granulation of zeolit...
Article
Full-text available
Building materials contribute a significant amount of CO 2 to overall greenhouse gas emissions and this environmental impact should be reduced to improve the sustainability of the construction industry. Although new and low-carbon materials are emerging, the majority of materials used are still traditionally produced and are highly carbon intensive...
Article
Full-text available
Technological, physical and mechanical properties of mineral binders are often defined by the amount of water add to the binder known as W/B ratio. The role of water is contributed to the workability of fresh paste, hydration processes, porosity, mechanical performance and durability of the material. Present research summarizes the relationship bet...
Article
Full-text available
A typical phenomenon in concrete structures is crack formation. Shrinkage cracks may appear in early stage of concrete. In late age cracks may appear due to process of serviceability and external weather conditions. Larger cracks interfere structural integrity, micro-cracks may result in durability problems as increase of water absorption, which re...
Article
Full-text available
Global warming being increasingly discussed, solutions for reducing emission greenhouse gases become more important in all industry sectors. The total energy consumed in the construction sector contribute up to 1/3 from all greenhouse gases emissions. Large part of it comes from the cement production – 5 % of the total global emissions. The foam co...
Conference Paper
Full-text available
Bio-based building materials (3BMs) are one of the solutions for how the construction industry can mitigate its negative environmental impact because of energy consumed in material production and due to the insufficient thermal insulation of buildings, as, in general, these materials sequester CO2 in them and have low thermal conductivity. One of t...
Article
In this study, and for the first time, the possibility of using bulk type waste-based granulated alkali-activated materials (AAM) for inducing heavy metals extraction by precipitation and adsorption was evaluated. Waste metakaolin and aluminium scrap recycling waste proved to be suitable precursors to create AAM. Results indicate that both methods...
Article
Full-text available
The growing interest of using industrial waste as recycled raw materials for the production of new, innovative materials is associated with effective use of natural resources and circular (zero-waste) economy. The research object is waste stream materials coming from chemical and processing industries, such as aluminum scrap recycling waste, chamot...
Article
The construction industry (and buildings) is one of the largest energy consuming and CO 2 emitting sectors in the world. To counter this, more lightweight structures are being used and energy saving applications are being developed. Phase change materials (PCM) are materials that can be considered to tackle these new challenges. It has been proven...
Conference Paper
Full-text available
The hemp-lime concrete as a self-bearing thermal insulation material has a low thermal conductivity and neutral CO2 emissions. However, the strength limitation of lime binder is an issue to use this material as a load-bearing material. Magnesium oxychloride binders are of considerably higher strength level and better bio-compatibility compared to t...
Article
Over the past years, the installations of Shallow Geothermal Energy (SGE) systems are increasing throughout Europe, and it is indicating that a specific and detailed legal framework is necessary. Towards this direction, this paper consists of an overview of legislation issues on SGE at European level, based on concise reviews from fourteen countrie...
Article
Dihydrate phosphogypsum (PG) from phosphate fertilizer production plant was considered as secondary raw material to produce gypsum binder. XRD was used to characterize mineral composition of raw material before and after heat treatment, as well as for hardened samples. Technological properties of obtained binder were determined regarding to the deh...
Article
Full-text available
Reduction of the CO2 emissions in the atmosphere is one of the goals set forth by the European Union, hence various directives have been adopted, such as the European directive 2012/27/EU on energy efficiency, i.e. ensuring from 2019 the construction of the near-zero energy buildings (nZEB). The construction segment plays a very important part in s...
Article
Full-text available
Over the last years there has been an increase in demand for construction materials that fulfil the high-level energy efficiency requirements while ensuring reduced impact on environment compared to the traditionally used materials. The hemp-lime concrete as a self-bearing thermal insulation material with low thermal conductivity and neutral CO2 em...
Article
Full-text available
The properties of lightweight geopolymer materials (GM) based on refractory technogenic aluminosilicate wastes were studied. The effect of the ratio of the oxides SiO2 and Al2O3 in the compositions of GM on the physical and mechanical properties of GM was investigated. It was found that SiO2/Al2O3 reduction in the GM composition results in higher d...
Article
To counter the negative environmental impact, particularly greenhouse gas emission generated by the construction industry, many low-impact materials are being produced and researched having neutral CO2 emissions and low thermal conductivity. One of these materials is lime-hemp concrete, a self-bearing bio-based insulation material with low thermal...
Article
Full-text available
The increasing concern for safety and sustainability of structures is calling for the development of smart self‐healing materials and preventive repair methods. The appearance of small cracks (<300 µm in width) in concrete is almost unavoidable, not necessarily causing a risk of collapse for the structure, but surely impairing its functionality, ac...
Article
Full-text available
In the present paper an attempt was made to evaluate reliability and efficiency of two freeze-thaw testing methods by testing high strength concrete (HSC) with two different supplementary cementitious materials as a partial substitute to cement in binary blend. Silica fume (SF) or metakaolin containing by-product (MKW) was used replacing with them...
Article
Full-text available
Alkali activated materials (AAM) based on calcined metakaolin or illite clay together with waste by-products, such as waste glass or aluminium scrap recycling waste, were tested as value-added materials for pH stabilization in biogas technology where decrease of pH should be avoided. Porous materials with ability to slowly leach alkalis in the wate...
Article
As the role that the society plays in energy and use of resources is of importance, what is vital is early education, as it is one of the pillars significantly influencing the planning of a “cleaner future” energywise, especially through utilizing energy-specific education techniques. Up to this point, it has been suggested that younger students te...
Article
Full-text available
The cement and concrete industries are continuously searching for new effective microfillers which could be obtained with relatively low cost, are wide spread and which improves most important concrete properties – strength and durability. Traditionally fine sand is used as inert mineral filler to the concrete mixture to make material structure com...
Article
Full-text available
The aim of this research is to estimate the effect of pozzolanic substitutes on the temperature generated by the hydration and on the final strength of concrete. Differential thermal analyses (DTA) were conducted. Ternary cementitious systems with different ratios of Portland cement, silica fume and calcined illite clay were investigated. The resul...
Chapter
The cementitious materials and ceramic industries are frequently looked as targets for the recycling and valorization of several wastes, residues, and by-products, generated from a wide variety of industries. In general, only technical (and chemical) aspects are covered on each attempt for recycling a waste in a particular product, while radiologic...
Article
Full-text available
The concrete industry is searching continuously for new effective mineral additives to improve the concrete properties. Replacing cement with the pozzolanic additives in most cases has resulted not only in positive impact on the environment but also has improved strength and durability of the concrete. Effective pozzolanic additives can be obtained...
Article
Full-text available
The usage of phase change materials (PCMs) is a way to store excess energy produced during the hot time of the day and release it during the night thereby reducing the overheating problem. While, in Latvian climate conditions overheating is not a big issue in traditional buildings since it happens only a couple of weeks per year air conditioners mu...
Article
Full-text available
The development of new materials to store thermal energy in a passive building system is a must to improve the thermal efficiency by thermal-regulating the indoor temperatures. This fact will deal with the reduction of the gap between energy supply and energy demand to achieve thermal comfort in building indoors. The aim of this work was to test pr...
Article
Full-text available
This study researches compressive strength and durability of the high strength self-compacting concrete (SCC) impacted at early stage by the curing conditions. The mixture compositions of metakaolin containing waste and cenospheres as partial cement replacement (15 wt%) were compared to reference SCC with 100% cement. The specimens prepared in adva...
Article
Full-text available
Alkali-activated materials (AAM) exhibit remarkable high-temperature resistance which makes them perspective materials for high-temperature applications, for instance as fire protecting and insulating materials in industrial furnaces. Series of experiments were carried out to develop optimum mix proportions of AAM based on chamotte with quartz sand...
Article
The primary object of the present research was to investigate the porous low calcium alkali activated material (AAM). Traditionally Na+ ions for alkali activation solution ensure highly alkaline media which enhances the dissolution of amorphous phase in the raw materials forming solid cementitious material with sodium aluminosilicate hydrate (N-A-S...
Conference Paper
Full-text available
The major CO2 emitting countries have concluded an agreement aimed at reducing the CO2 emissions at the Paris Climate Conference 2015. However, the emission levels are still on the rise. As the building material industry is one of the largest producers of CO2, it should find solutions to limit these emissions, such as development of new materials w...
Article
h i g h l i g h t s Industrial by-products as precursor of lightweight alkali activated materials. Highly porous lightweight building materials were obtained with a density from 380 to 470 kg/m 3. Steel plant waste retards pore formation providing homogeneous pore distribution; Alkali activation of raw materials shift the crystalline phase to an am...
Article
This study focuses on the properties of porous alkali activated materials (AAM) involving the reactive phases of the raw materials. Two types of calcined clays (illite – IC and metakaolin – WMK) and aluminium scrap recycling waste (ASRW) were considered as precursors for alkali activation. The porous AAM were obtained using ASRW with a different ma...
Article
The use of wastes for developing of new materials is a sustainable approach. In current study filter media produced from industrial waste was tested for an ability to decrease high concentration of zinc in standard solution and industrial wastewater. The geopolymer production requires mixing of post-industrial waste with naturally occurred aluminos...