Genādijs Šahmenko

Verified email at rtu.lv

Faculty of Civil Engineering
Riga Technical University



                       

https://researchid.co/genadijs

EDUCATION

2005 Doctor’s degree of engineering sciences, Riga Technical University, ISCED 2011 – 8.lev.;
1994 Master’s degree of engineering sciences, Riga Technical University, ISCED 2011 – 7.level;
1991 Bachelor’s degree engineering sciences, Riga Technical University, ISCED 2011 – 6.level;

RESEARCH INTERESTS

High Performance Concrete, Cement Composite, Concrete non-destructive testing, Eco-materials, Hemp concrete

57

Scopus Publications

Scopus Publications

  • Creep and shrinkage behaviour of disintegrated and non-disintegrated cement mortar
    Rihards Gailitis, Beata Figiela, Kalvis Abelkalns, Andina Sprince, Genadijs Sahmenko, Marta Choinska, and Martin Duarte Guigou

    Materials, eISSN: 19961944, Published: December-2 2021 MDPI AG
    One way to prevent cement from ending up in landfills after its shelf life is to regain its activity and reuse it as a binder. As has been discovered, milling by planetary ball mill is not effective. Grinding by collision is considered a more efficient way to refine brittle material and, in the case of cement, to regain its activity. There has been considerable research regarding the partial replacement of cement using disintegrated cement in mortar or concrete in the past few decades. This article determines and compares the creep and shrinkage properties of cement mortar specimens made from old disintegrated, old non-disintegrated, and new non-disintegrated Portland cement. The tests show that the creep strains for old disintegrated and old non-disintegrated cement mortars are close, within a 2% margin of each other. However, the creep strains for new non-disintegrated cement mortar are 30% lower. Shrinkage for old disintegrated and non-disintegrated cement mortar is 20% lower than for new non-disintegrated cement mortar. The research shows that disintegration is a viable procedure to make old cement suitable for structural application from a long-term property standpoint. Additionally, it increases cement mortar compressive strength by 49% if the cement is disintegrated together with sand.

  • Recycling of rice husks ash for the preparation of resistant, lightweight and environment-friendly fired bricks
    Construction and Building Materials, ISSN: 09500618, Volume: 302, Published: 4 October 2021

  • Modification of the structure and properties of lightweight cement composite with pva fibers
    Donatas Sikarskas, Valentin Antonovič, Jurgita Malaiškienė, Renata Boris, Rimvydas Stonys, and Genadijs Šahmenko

    Materials, eISSN: 19961944, Published: October-2 2021 MDPI AG
    This study addresses the application of polyvinyl alcohol (PVA) fibers to improve the performance of lightweight cement composites with pozzolans. Blended cement mixes based on expanded glass granules were modified with PVA fibers (Type A: Ø40 µm, L = 8 mm and Type B: Ø200 µm, L = 12 mm). The following research methods were used to analyse the effect of the fibers on the structure of cement matrix and physical-mechanical properties of lightweight composite: SEM, XRD, DTG, calorimetry tests, and standard test methods of physical and mechanical properties. Results from the tests showed that a denser layer of hydrates was formed around the PVA fiber and the amounts of portlandite, CSH, and CASH formed in the specimens with PVA were found to be higher. PVA fibers of Type A accelerated hydration of the cement paste, slightly increased the compressive strength of the lightweight composite, but had no significant effect on the values of density, ultrasonic pulse velocity and flexural strength. The shrinkage of cement composite was significantly reduced using both types of PVA fiber and both types of PVA fibers increased the fracture energy of lightweight cement composite with expanded granules.

  • Alternative non-destructive method for strength testing of structural concrete
    Modests Elemba, Videvuds-Arijs Lapsa, Genadijs Šahmenko, and Aleksandrs Korjakins

    Journal of Physics: Conference Series, ISSN: 17426588, eISSN: 17426596, Volume: 1889, Published: 18 May 2021 IOP Publishing
    This work proposes an original and active method for non-destructive testing of concrete and can also be used for other building materials. The proposed method includes the successive steps of: drilling holes into samples of building material with use of rotation or percussion drilling machine and simultaneously determining the power consumption necessary for drilling; strength determination of building material by destructive failure of samples; obtaining a positive empiric correlation between the power consumption necessary for drilling and determined strength values of material; control during drilling the holes in structure material being tested and simultaneously determining the power consumption necessary for drilling; determining the actual strength of structure material being tested by use of correlation between power consumption and material strength values derived in testing process. The application of the method makes strength determination of building materials simpler and faster and also increases the accuracy of testing.

  • Properties of magnesium oxychloride and magnesium oxysulphate cement composites
    Elvija Namsone, Genadijs Sahmenko, and Aleksandrs Korjakins

    Key Engineering Materials, ISSN: 10139826, eISSN: 16629795, Volume: 903 KEM, Pages: 208-213, Published: 2021 Trans Tech Publications, Ltd.
    Increasing energy consumption is forcing the building sector to seek and use building materials and products that would be environmentally friendly. As one such material should be noted magnesium based cements, which production requires much lower calcination temperature than the traditional Portland cement. During the experimental research part of this work, two types of magnesia cement were produced (using magnesium chloride and magnesium sulphate brine solutions) and physical, mechanical properties of obtained cement composites were determined.

  • Sustainable Wall Solutions Using Foam Concrete and Hemp Composites
    G. Šahmenko, M. Sinka, Eva Namsone, A. Korjakins and D. Bajare

    Environmental and Climate Technologies, eISSN: 22558837, Pages: 917-930, Published: 1 January 2021
    Abstract 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 (autoclaved aerated concrete) and normal concrete. Advanced materials, such as high-performance foamed concrete (HPFC) and natural biofibre composites, have been evaluated as an alternative solution. Ultra-light foam concrete was applied as an alternative for polymer-based insulation. The next development was sandwich three-layer wall constructions consisting of foam concrete and natural biofibre composites. A prototype of a wall panel was elaborated with outer layers of high-density bio-composite and a middle layer of high porosity hemp composite. Basic properties of sandwich blocks, such as density and thermal conductivity, were evaluated and compared. The environmental impact of the studied wall systems was analysed using a life-cycle assessment (LCA) to assess carbon dioxide emissions during the production phase of the material. The results show that replacing traditional insulation with bio-based materials has greatly reduced the negative environmental impact of the wall elements. A combination of natural fibre bio-composite and mineral insulating foam makes it possible to obtain an eco-friendly and sustainable sandwich-type wall system.

  • Production of magnesium binder composites using local raw materials and technogenic products
    Elvija Namsone, Genadijs Sahmenko, and Aleksandrs Korjakins

    Vide. Tehnologija. Resursi - Environment, Technology, Resources, ISSN: 16915402, Pages: 236-241, Published: 2021 Rezekne Academy of Technologies
    Building sector is known as one of the biggest polluters, causing environmental pollution and carbon dioxide emissions, most of which are generated during the production process of building materials. Therefore, researchers and manufacturers have become increasingly interested in environmentally friendly materials with low energy consumption. Magnesium based cements are being studied as an alternative to a widespread material as Portland cement, thus reducing the temperature required for calcination. During this research, magnesium binder-based composites using two types of magnesium (local dolomite waste material and caustic magnesia) were produced. Within the framework of this study, several regimes of thermal treatment were used to produce low carbon dioxide and environmentally friendly magnesium binder composites. Physical, mechanical and thermal properties of obtained specimens were tested. 

  • Development of high-strength foamed concrete compositions
    Eva Namsone, Genadijs Sahmenko, Elvija Namsone, and Aleksandrs Korjakins

    Solid State Phenomena, ISSN: 10120394, eISSN: 16629779, Volume: 320 SSP, Pages: 186-190, Published: 2021 Trans Tech Publications, Ltd.
    Unlike traditional materials, the development of high-performance foamed concrete with a compressive strength of up to 20 MPa and a density of up to 1400 kg/m3 allows the use of foamed concrete as a constructive material with additional functions including good thermal insulation properties, sound insulation and capillary porosity needed to ensure hydrothermal conditions. Unlike autoclaved aerated concrete, foamed concrete can also be used in monolithic construction.The studies of high strength foamed concrete were performed by using mostly local mineral components and mixing technology by using planetary activator which provides a fundamentally new mixing mode that combines intensive mixing, foaming and activation of components. To realize the experimental part of the research, turbulence type foamed concrete mixer SPBU-LUKS was used.

  • Mechanical and thermal properties of magnesia binder based on natural and technogenic raw materials
    Elvija Namsone, Genadijs Sahmenko, Irina Shvetsova, and Aleksandrs Korjakins

    Solid State Phenomena, ISSN: 10120394, eISSN: 16629779, Volume: 320 SSP, Pages: 181-185, Published: 2021 Trans Tech Publications, Ltd.
    Because of low calcination temperature, magnesia binders are attributed as low-CO2 emission materials that can benefit the environment by reducing the energy consumption of building sector. Portland cement in different areas of construction can be replaced by magnesia binder which do not require autoclave treatment for hardening, it has low thermal conductivity and high strength properties. Magnesium-based materials are characterized by decorativeness and ecological compatibility.The experimental part of this research is based on the preparation of magnesia binders by adding raw materials and calcinated products and caustic magnesia. The aim of this study was to obtain low-CO2 emission and eco-friendly material using local dolomite waste materials, comparing physical, mechanical, thermal properties of magnesium binders.

  • Fast setting binders for application in 3d printing of bio-based building materials
    Maris Sinka, Jelizaveta Zorica, Diana Bajare, Genadijs Sahmenko, and Aleksandrs Korjakins

    Sustainability (Switzerland), eISSN: 20711050, Pages: 1-12, Published: 1 November 2020 MDPI AG
    The construction industry is one of the largest emitters of CO2 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 due to their bio-based components and efficient use of the materials through 3D printing. Agricultural waste products—hemp shives—are used in these materials as a filler together with three different types of fast-setting binders—magnesium, calcium sulphoaluminate (CSA) and those that are gypsum-based. The study determines the setting time and compressive strength of these binders, as well as the formation of biocomposites of different densities for different applications; extrusion tests and preliminary life cycle assessment (LCA) are also performed. Results show that biocomposites with hemp shives and fast setting binders have a possible application in 3D printing due to their shape stability and buildability, as well as relatively high compressive strength, which allows for load-bearing use at high densities and thermal insulation use at low densities, although printability at low binder content remains a significant challenge. Preliminary LCA results show that CSA and gypsum binders have the lowest environmental impact from the binders considered.

  • Magnesium-based binders and its materials
    Elvija Namsone, Irina Shvetsova, Genadijs Sahmenko, and Aleksandrs Korjakins

    Key Engineering Materials, ISSN: 10139826, eISSN: 16629795, Volume: 850 KEM, Pages: 305-310, Published: 2020 Trans Tech Publications, Ltd.
    The experimental research work is dedicated to magnesium-based binders. Two types of magnesium oxide were added in the compositions of binders – caustic magnesia and raw materials and calcinated products. Dolomite waste material (dolomite powder) from three quarries (two in Latvia, one in Russia) was tested. Magnesium-based binders are described as low-CO2 emission materials, helping to reduce the energy consumption in building sector. The aim of this study is to investigate the possibility to obtain eco-friendly, low-CO2 emission binding material from local dolomite waste materials and research the physical, mechanical and thermal properties of obtained samples.

  • Production of foamed concrete in a planetary ball mill
    Eva Namsone, Genadijs Sahmenko, Elvija Namsone, and Aleksandrs Korjakins

    Key Engineering Materials, ISSN: 10139826, eISSN: 16629795, Volume: 850 KEM, Pages: 311-315, Published: 2020 Trans Tech Publications, Ltd.
    Nowadays, the type of foamed concrete performs a group of cemented composite materials that can compete with conventionally used autoclaved aerated concrete. Improving microstructure of the foamed concrete by inventive mixing technology allows to homogenizate the mix of foamed concrete. This original research is applied to inspection on mixing technology of foamed concrete by using a planetary ball mill. The objective of this paper is to clarify the correlation between physical-mechanical properties and intensive mixing time.

  • High-performance concrete using dolomite by-products
    G. Sahmenko, A. Korjakins, and D. Bajare

    RILEM Bookseries, ISSN: 22110844, eISSN: 22110852, Pages: 99-103, Published: 2020 Springer International Publishing
    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-products are deposited in a single quarry and the annual increase of this material is 50 000 t.

  • Durability characterisation of glass fibre reinforced concrete by resistance to freezing and thawing
    Rimvydas Moceikis, Asta Kičaitė, Genadijs Sahmenko, and Aušra Selsekienė

    Journal of Sustainable Architecture and Civil Engineering, ISSN: 20299990, eISSN: 23352000, Pages: 98-109, Published: 2020 Kaunas University of Technology (KTU)
    Resistance to freezing and thawing of glass fibre reinforced concrete (GRC) modified with silica fume and metakaolin was tested according to scaling at freezing test method with de-icing salt after 112 cycles. Surface mass loss was obtained, flexural strain energies calculated from load- deformation curves and ductile/ brittle behavior of GRC composite explained. SEM micrograph analysis was used to identify possible flaws on the surface of filaments and fiber-matrix contact zone due to freeze-thaw influence.

  • Numerical Comparison of HPFRC and HPC Ribbed Slabs
    K Buka-Vaivade, J Sliseris, D Serdjuks, G Sahmenko, and L Pakrastins

    IOP Conference Series: Materials Science and Engineering, ISSN: 17578981, eISSN: 1757899X, Volume: 660, Published: 5 December 2019 IOP Publishing

  • Investigations on the foam concrete production techniques suitable for 3D-printing with foam concrete
    V Markin, G Sahmenko, V N Nerella, M Näther, and V Mechtcherine

    IOP Conference Series: Materials Science and Engineering, ISSN: 17578981, eISSN: 1757899X, Volume: 660, Published: 5 December 2019 IOP Publishing

  • Properties of thin wall cement composites reinforced with AR glass, carbon and PVA fibres
    R Moceikis, A Kičaitė, G Sahmenko, and A Korjakins

    IOP Conference Series: Materials Science and Engineering, ISSN: 17578981, eISSN: 1757899X, Volume: 660, Published: 5 December 2019 IOP Publishing

  • Drying Shrinkage Deformation Comparison between Foam Concrete, Geopolymer Concrete, Disintegrated, and Non-disintegrated Cement Mortar
    R Gailitis, A Sprince, L Pakrastins, G Sahmenko, and T Kozlovskis

    IOP Conference Series: Materials Science and Engineering, ISSN: 17578981, eISSN: 1757899X, Volume: 660, Published: 5 December 2019 IOP Publishing

  • Life Cycle Assessment of Foam Concrete Production in Latvia
    Zinta Zimele, Maris Sinka, Aleksandrs Korjakins, Diana Bajare, and Genadijs Sahmenko

    Environmental and Climate Technologies, eISSN: 22558837, Pages: 70-84, Published: 1 December 2019 Walter de Gruyter GmbH
    Abstract 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 concrete is lightweight concrete with good thermal properties and ability to reduce CO2 emissions by reducing the use of cement due to its low density. The aim of this study is to determine impact on the environment with the use of Life Cycle Assessment (LCA) with focus on Global Warming Potential (GWP) for two different compressive strength foam concrete mixtures produced in Latvia by unique intensive mixing technology – turbulence with cavitation effect. Afterwards, the selected foam concrete mixtures are compared with alternative materials with similar compressive strength – aerated concrete and hollow ceramic blocks. The foam concrete mixture having 12.5 MPa compressive strength showed higher CO2 emissions than hallow ceramic block. The majority of CO2 emissions comes from the Portland cement, which is a key element in its composition. On the other hand, the foam concrete mixture having 2.4 MPa compressive strength showed higher CO2 emissions than aerated concrete block. The majority of CO2 emissions are due to foam glass granules, which is the main element contributing to the increased insulation properties of the material. Comparison of each foam concrete with analogue building material by compressive strength shows that the chosen foam concrete mixtures produce greater GWP than alternative materials. This research allows to identify the environmental impacts of different foam concrete mixture components and to improve these mixtures to achieve similar properties with less impact, for example, by replacing foam glass granules with granules made from recycled glass or replacing cement with flay ash, silica fume or recycled glass powder.

  • Research on properties of composites based on magnesium binders
    Elvija Namsone, Genadijs Sahmenko, Endija Namsone, Eva Namsone, and Aleksandrs Korjakins

    Vide. Tehnologija. Resursi - Environment, Technology, Resources, ISSN: 16915402, Pages: 192-197, Published: 2019 Rezekne Academy of Technologies
    The research is devoted to composites based on magnesium binders, which is very perspective building material in the modern construction industry. Magnesium based binders have better compatibility with organic fillers comparing to traditionally lime binder cement [1]. In this investigation two magnesium-based binders are used, such as magnesium chloride and magnesium sulphate. The aim of this study is to investigate the physical, mechanical and durability properties of composites based on magnesium binders, such as density, compressive strength, thermal conductivity and capillary water absorption, and to obtain magnesium binder that could be used to produce foamed concrete. This can be done by improving the composition of the mixture. In this framework properties of magnesium binders are analysed and how these binders can affect to the properties of magnesium based composites.

  • Comparison of the long-term properties in compression of different size foamed concrete
    Rihards Gailītis, Andina Sprince, Leonids Pakrastins, Genadijs Shakhmenko, and Tomass Kozlovskis

    Vide. Tehnologija. Resursi - Environment, Technology, Resources, ISSN: 16915402, Pages: 41-44, Published: 2019 Rezekne Academy of Technologies
    Foamed concrete has been used as a building material since the early 1920s. In the beginning, it was used as an insulation material with very low density. Since then there have been attempts to make this material more load-bearing and structural. In the present-day foamed concrete is being used in soil reinforcement, manufacturing of building blocks and other sorts of construction materials. [1] The aim of this article is to determine long-term properties and strength of foamed concrete specimens as well as compare the results between two differently sized foamed concrete specimens. The size of creep and shrinkage specimens were Ø46x190 mm and Ø75x180 mm. The creep properties of the specimens were determined by loading them with 20% of the ultimate stress value. [2] The compressive strength, creep and specific creep of specimens were determined as well as specimen size factor to creep deformations.

  • Comparative life cycle assessment of magnesium binders as an alternative for hemp concrete
    Maris Sinka, Philip Van den Heede, Nele De Belie, Diana Bajare, Genadijs Sahmenko, and Aleksandrs Korjakins

    Resources, Conservation and Recycling, ISSN: 09213449, eISSN: 18790658, Volume: 133, Pages: 288-299, Published: June 2018 Elsevier BV
    Abstract 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 conductivity and good CO2 uptake but with weak mechanical properties. In this study alternative magnesium binders are proposed to substitute the traditionally used lime binder in hemp concrete, comparing the environmental impact of these binder composites. To make the comparison, experimental mixtures with both traditionally used and alternative binder composites were produced and their mechanical and thermal properties tested. The magnesium binders showed promising results as these composites were approximately two times stronger, having similar density and thermal conductivity. Afterwards the Life Cycle Assessment (LCA) was carried out to evaluate and compare the environmental impact of all tested composites. Lime based binder composites achieved negative CO2 emissions, varying from −46.5 to −68.6 kg CO2/m3. Alternative binder, magnesium phosphate cement, demonstrated significantly greater environmental impact than all other binders due to its hardener, potassium phosphate, which is highly energy and resource intensive. Magnesium oxychloride cement showed promising results with bio-based filler, as their combined environmental impact was lower in most categories compared to lime-hemp concrete, and negative CO2 emissions of −37.38 kg CO2/m3 were achieved. These negative CO2 emissions were achieved with biogenic CO2 uptake from hemp growth and low binder content, thus achieving low thermal conductivity of 0.062 W/m2*K at 214 kg/m3 density.

  • Research on properties of high performance foamed concrete
    Eva Namsone, Genadijs Sahmenko, Elvija Namsone, and Aleksandrs Korjakins

    Key Engineering Materials, ISSN: 10139826, eISSN: 16629795, Volume: 788 KEM, Pages: 13-22, Published: 2018 Trans Tech Publications, Ltd.
    The research is devoted to foamed concrete, which is a very perspective material in the modern construction industry. Foamed concrete is lightweight concrete and is in accordance with compressive strength and the use of it: constructive, constructive-insulating and lightweight foamed concrete.

  • Bio-based construction panels for low carbon development
    Maris Sinka, Aleksandrs Korjakins, Diana Bajare, Zinta Zimele, and Genadijs Sahmenko

    Energy Procedia, ISSN: 18766102, Volume: 147, Pages: 220-226, Published: 2018 Elsevier BV
    Abstract 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 emissions is one of such materials that can ensure it. However due to its limited strength the use of this material is problematic in projects of industrial scale. Magnesium oxychloride binders are of considerably higher strength level and better bio-compatibility compared to the lime-based binders, hence in this research the former were used in combination with a hemp filler to produce composite materials to be used in production of construction panels for industrial scale. These panels consist of an outer and inner border layer and a middle thermal insulation layer, that can be provided by magnesium-hemp concrete with varied amount of the binder added. To evaluate impact on environment of such panels, the Life cycle assessment was performed, analyzing amount of CO2 produced by them and comparing it to the traditionally used materials with similar thermal transmittance properties. Results of the research showcase that the magnesium-hemp concrete can be used in production of bio-based construction panels because strength of their outer layers can reach up to 1.2 MPa at 450 kg/m3 density and that of the inner layer – 0.06 W/m·K at 200 kg/m3 density. It was proved in the research that the magnesium-hemp panel represents reduced impact on environment because a panel, 370 mm thick, that ensures the U value of 0.18, emits 12.7 kg/CO2 eq. m2, that is 5 times less compared to the traditionally used materials.

  • Effect of various additives and aeration on the properties of lightweight concrete
    Genadijs Sahmenko, Eva Namsone, Kristaps Rubenis, Arita Dubnika, and Guntars Niparts

    Key Engineering Materials, ISSN: 10139826, eISSN: 16629795, Volume: 762, Pages: 351-355, Published: 2018 Trans Tech Publications, Ltd.
    In the present study the effect of various additives (silica sand, silica fume, zeolite and cenospheres) as well as the aeration on the properties (consistency, density, compressive and bending strength) of lightweight concrete was studied. Density, compressive and bending strength of the lightweight concrete were substantially reduced by replacing silica sand with censopheres or by adding air entraining agent to the grout used for the preparation of the samples. Silica fume and zeolite admixture improved mechanical properties of the samples. Specific compressive strength of the cenospheres containing samples is comparable or even higher than the ones made of the mixes without the cenospheres.

GRANT DETAILS

Participation at the Latvian Council of Science funding project “Long-term properties of innovative cement composites in various stress-strain conditions” (No. lzp-2018/2-0249")

INDUSTRY EXPERIENCE

Development production technology in paving brick plant, foam concrete plant. Work in testing laboratory.

SOCIAL, ECONOMIC, or ACADEMIC BENEFITS

2008. Member of Latvian Concrete Society (LCA), from 2017. chairman of the board of LCA. duties: the advancement of science in the concrete industry, development of recommendation for new specification, standards and lows in the field of concrete industry.
2016. Member of American Concrete Institute (ACI) Committee 523 – Cellular Concrete.