Rihards Gailitis

Verified email at rtu.lv

Department of Structural Engineering / Faculty of Civil Engineering
Institute of Structural Engineering and Reconstruction / Riga Technical University



                                               

https://researchid.co/rihards

2018 – 2020 Latvian Council of Science Fund (LZP-2018/2-0249) „Long-term properties of innovative cement composites in various stress-strain conditions”; researcher

EDUCATION

2018 – present PhD in Construction Materials and Technology, Structural Engineering, Faculty of Civil Engineering, Riga Technical University, Riga, Latvia
2017 – 2018 Professional Master's degree in Civil Engineering, Riga Technical University, Riga, Latvia
2012 – 2017 Professional Bachelor's degree in Civil Engineering and Civil Engineer's qualification, Riga Technical University, Riga, Latvia

RESEARCH INTERESTS

Alkali activated cement composites, geopolymer composites, cement composites, creep and shrinkage strains, long - term deformations, Image analysis of polished and thin sections, polished section analysis using SEM

13

Scopus Publications

65

Scholar Citations

6

Scholar h-index

3

Scholar i10-index

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.

  • Tensile creep of cement and concrete composites: Monitoring by means of 2D-digital image correlation
    Andina Sprince, Tomass Kozlovskis, Rihards Gailitis, Juozas Valivonis, Kinga Korniejenko, and Arnaud Castel

    Applied Sciences (Switzerland), eISSN: 20763417, Published: September 2021 MDPI AG
    Creep and shrinkage of Cement and Concrete Composites (CCC) are significant properties that need to be considered to use these materials in practice. Many previous scientific studies revealed CCC creep characteristics under sustained compression and shrinkage, using traditional test methods from design standards. Because of the complexity of experimental procedures, CCC creep in tension has not been studied as close. Furthermore, there is no unified standard that proposes applicable testing methods or specific testing apparatus. This study examines the suitability of 2D—Digital Image Correlation (DIC) to observe the creep deformations of specimens under tension. Ordinary Portland cement (OPC) mortar with 1% polyvinyl alcohol (PVA) fibres has been investigated in the research. Compact tension (CT) specimens 150 × 150 × 12 mm (with a notch) were used. Creep deformations under sustained uniaxial tension (applied loading corresponding to 60% of the ultimate strength) were measured. DIC images were captured using an entry/mid-level DSLR camera. Results show that DIC is suitable for studying uniaxial tensile creep of cement and concrete composites. Deformation of specimens in tension was similar to that measured using the conventional method (using surface-attached gauges).

  • Foamed geopolymer composites with the addition of glass wool waste
    Barbara Kozub, Patrycja Bazan, Rihards Gailitis, Kinga Korniejenko, and Dariusz Mierzwiński

    Materials, eISSN: 19961944, Published: September 2021 MDPI AG
    This study examines foamed geopolymer composites based on fly ash from the Skawina coal-fired power plant in Poland. The paper presents the effect of adding 3% and 5% by weight of glass wool waste on selected properties of foamed geopolymers. The scope of the tests carried out included density measurements, compressive and bending strength tests, measurements of the heat conduction coefficient, and the results of measurements of changes in thermal radiation in samples subjected to a temperature of 800 °C. The obtained results indicate that glass wool waste can be successfully used to lower the density and heat conduction coefficient of foamed geopolymer composites with a fly ash matrix. In addition, the results of changes in thermal radiation in the samples subjected to the temperature of 800 °C showed a positive effect of the addition of glass wool waste. Moreover, the introduction of the addition of glass wool waste made it possible to increase the compressive strength of the examined foamed geopolymers. For the material modified with 3% by weight of mineral wool, the increase in compressive strength was about 10%, and the increase in fibers in the amount of 5% by weight resulted in an increase of 20% concerning the base material. The obtained results seem promising for future applications. Such materials can be used in technical constructions as thermal insulation materials.


  • Long-term properties of cement mortar under compression, tension, and 3-point bending
    N. Vatin, A. Sprince, R. Gailitis, L. Pakrastins and T. Kozlovskis

    Magazine of Civil Engineering, eISSN: 27128172, Volume: 105, Published: 2021
    Cement composite long-term property assessment usually is limited to the compression strain state due to the difficulty of performing long-term tests in tension and 3-point bending. This paper shows the difference in long-term properties in compression, tension, and 3-point bending for plain ordinary Portland cement mortar (OPC). The obtained results were compared to reinforced specimen results to determine whether the PVA refibres improve the long-term properties of OPC mortar in various stress-strain conditions. Cylinders, compact tension specimens (CT), and beams – plates were prepared to evaluate material properties and the role of fibre reinforcement in these different stress states. Additionally, to conventional surface-attached strain gauges, 2D-DIC was employed to observe the creep strain of specimens in tension. This paper aim to determine long-term property differences in compression, tension and 3-point bending and, also, to see if low amount PVA fibre incorporation improve long-term properties in previously stated stress-strain states. It was determined that the usage of 1 % of PVA fibres increases creep strains in compression on average by 15 % and reduced by 7 % in tension. It reduces shrinkage strain by 18 % in compression and 8 % in tension. The long-term deflection for the PVA fibre-reinforced specimens are, on average by 55 % higher than for plain OPC mortar specimens in 3-point bending.

  • Plain and PVA fibre-reinforced geopolymer compact tension specimen critical area surface composition assessment
    Rihards Gailītis, Andina Sprince, Leonids Pakrastins, Patrycja Bazan, and Kinga Koniejenko

    Vide. Tehnologija. Resursi - Environment, Technology, Resources, ISSN: 16915402, Pages: 72-77, Published: 2021 Rezekne Academy of Technologies
    For more than 40 years, low calcium alkali-activated cement composite, or in other words, geopolymer, has been around. In recent years there has been increased interest in this material and its properties. It is mainly due to the claim that geopolymer is the cement of the future. This claim is based on environmental factors. For instance, the CO2 emissions for geopolymer binder can be up to 6 less than for Portland cement binder. Most of the researches regarding geopolymer composite properties examine only mechanical and long-term properties in compression. There has been a lack of long-term tests in tension due to difficulties in performing them. As the tensile stresses are an essential part of structure assessment, it is necessary to evaluate new material properties as thoroughly as possible. Due to the nature of geopolymer specimen hardening (polymerisation), there is a difference in modulus of elasticity development and shrinkage caused by binding that could have factors that regular Portland cement specimens do not.This article aims to evaluate the surface composition of plain and 1% PVA reinforced geopolymer compact tension specimens that have been subjected to creep and shrinkage tests. Specimen cross-section images were acquired using the scanning electron microscope (SEM). Using the quantitative image analysis method, amounts of cross-section composition elements are determined. Furthermore, the amount of cracks is determined and compared between plain and PVA fiber-reinforced specimens.It has been determined that even though 1% of PVA fibre-reinforced specimens have lower tensile strength, their creep and shrinkage strains are lower, and the number of microcracks at the notch base of the specimen. Still, it has to be acknowledged that the amount of air voids in all analysed specimens is relatively high.  

  • Plain Geopolymer Concrete Cross-Section Surface Analysis After Creep and Shrinkage Tests in Compression and Tension
    Rihards Gailitis, Andina Sprince, Leonids Pakrastins, Kinga Korniejenko, and Tomass Kozlovskis

    RILEM Bookseries, ISSN: 22110844, eISSN: 22110852, Pages: 13-24, Published: 2021 Springer International Publishing

  • Comparison of the long-term properties of foamed concrete and geopolymer concrete in compression
    Rihards Gailitis, Kinga Korniejenko, Andina Sprince, and Leonids Pakrastins

    AIP Conference Proceedings, ISSN: 0094243X, eISSN: 15517616, Volume: 2239, Published: 22 May 2020 AIP Publishing

  • Long-Term Deformation Properties of a Carbon-Fiber-Reinforced Alkali-Activated Cement Composite
    R. Gailitis, J. Sliseris, K. Korniejenko, J. Mikuła, M. Łach, L. Pakrastins, and A. Sprince

    Mechanics of Composite Materials, ISSN: 01915665, eISSN: 15738922, Pages: 85-92, Published: 1 March 2020 Springer Science and Business Media LLC

  • Long-Term Parameters of New Cement Composites
    Andina Sprince, Leonids Pakrastins, and Rihards Gailitis

    RILEM Bookseries, ISSN: 22110844, eISSN: 22110852, Pages: 85-94, Published: 2020 Springer International Publishing

  • Mechanical Properties of Geopolymer Concretes Reinforced with Waste Steel Fibers
    R Gailitis, K Korniejenko, M Łach, J Sliseris, J Morán, E Rodriguez, and J Mikuła

    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

  • 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.

RECENT SCHOLAR PUBLICATIONS

  • Creep and Shrinkage Behaviour of Disintegrated and Non-Disintegrated Cement Mortar
    R Gailitis, B Figiela, K Abelkalns, A Sprince, G Sahmenko, M Choinska, ...
    Materials 14 (24), 7510 2021

  • Tribo-Mechanical Behavior of Geopolymer Composites with Wasted Flax Fibers
    P Bazan, B Kozub, K Korniejenko, R Gailitis, A Sprince
    IOP Conference Series: Materials Science and Engineering 1190 (1), 012030 2021

  • Tensile creep of cement and concrete composites: Monitoring by means of 2D-digital image correlation
    A Sprince, T Kozlovskis, R Gailitis, J Valivonis, K Korniejenko, A Castel
    Applied Sciences 11 (18), 8334 2021

  • Foamed geopolymer composites with the addition of glass wool waste
    B Kozub, P Bazan, R Gailitis, K Korniejenko, D Mierzwiński
    Materials 14 (17), 4978 2021

  • Long-term properties of different fiber reinforcement effect on fly ash-based geopolymer composite
    R Gailitis, A Sprince, T Kozlovskis, L Radina, L Pakrastins, N Vatin
    Crystals 11 (7), 760 2021

  • Plain and PVA Fibre-Reinforced Geopolymer Compact Tension Specimen Critical Area Surface Composition Assessment
    R Gailitis, A Sprince, L Pakrastins, P Bazan, K Korniejenko
    ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International 2021

  • Plain Geopolymer Concrete Cross-Section Surface Analysis After Creep and Shrinkage Tests in Compression and Tension
    R Gailitis, A Sprince, L Pakrastins, K Korniejenko, T Kozlovskis
    International RILEM Conference on Early-age and Long-term Cracking in RC 2021

  • Long-term properties of cement mortar under compression, tension, and 3-point bending
    T Kozlovskis, N Vatin, A Sprince, R Gailitis, L Pakrastins
    Magazine of Civil Engineering 105 (5), 10511-10511 2021

  • Mechanical properties of hybrid cotton and steel fiber reinforced fly-ash based geopolymer composites
    A Bąk, B Figiela, M Łach, R Gailitis, WT Lin, K Korniejenko
    2021

  • Long-term properties of cement mortar under compression, tension, and 3-point bending
    S Andina, G Rihards, P Leonids, K Tomass, V Nikolai
    Magazine of Civil Engineering, 10511 2021

  • Mierzwi nski, D
    B Kozub, P Bazan, R Gailitis, K Korniejenko
    Korniejenko, K. Fly-ash-based geopolymers reinforced by melamine fibers 2021

  • Reinforced and plain geopolymer concrete specimen cross-section composition influence on creep strains
    R Gailitis, A Sprince, L Pakrastins, K Korniejenko, T Kozlovskis
    2021

  • Comparison of the long-term properties of foamed concrete and geopolymer concrete in compression
    R Gailitis, K Korniejenko, A Sprince, L Pakrastins
    AIP Conference Proceedings 2239 (1), 020012 2020

  • Long-Term Deformation Properties of a Carbon-Fiber-Reinforced Alkali-Activated Cement Composite
    R Gailitis, J Sliseris, K Korniejenko, J Mikuła, M Łach, L Pakrastins, ...
    Mechanics of Composite Materials 56 (1), 85-92 2020

  • Long-term parameters of new cement composites
    A Sprince, L Pakrastins, R Gailitis
    International Conference on Application of Superabsorbent Polymers & Other 2019

  • Mechanical properties of geopolymer concretes reinforced with waste steel fibers
    R Gailitis, K Korniejenko, M Łach, J Sliseris, J Morn, E Rodriguez, ...
    IOP Conference Series: Materials Science and Engineering 660 (1), 012007 2019

  • Drying Shrinkage Deformation Comparison Between Foam Concrete, Geopolymer Concrete, Disintegrated, and Non-disintegrated Cement Mortar
    R Gailitis, A Sprince, L Pakrastins, G Sahmenko, T Kozlovskis
    IOP Conference Series: Materials Science and Engineering 660 (1), 012036 2019

  • Comparison of the Long-Term Properties in Compression of Different Size Foamed Concrete
    R Gailītis, A Sprince, L Pakrastins, G Shakhmenko, T Kozlovskis
    ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International 2019

  • Long-term properties of foamed concrete
    R Gailitis, A Sprince, L Pakrastins, G Shakhmenko, T Kozlovskis, ...
    2019

  • Research on creep of high performance foamed concrete cylinders in compression
    E Namsone, R Gailitis, L Pakrastins, G Sahmenko, E Namsone
    8th International Conference on Safety and Durability of Structures, 18 2018

MOST CITED SCHOLAR PUBLICATIONS

  • Mierzwi nski, D
    B Kozub, P Bazan, R Gailitis, K Korniejenko
    Korniejenko, K. Fly-ash-based geopolymers reinforced by melamine fibers 2021
    Citations: 13

  • Long-term parameters of new cement composites
    A Sprince, L Pakrastins, R Gailitis
    International Conference on Application of Superabsorbent Polymers & Other 2019
    Citations: 11

  • Foamed geopolymer composites with the addition of glass wool waste
    B Kozub, P Bazan, R Gailitis, K Korniejenko, D Mierzwiński
    Materials 14 (17), 4978 2021
    Citations: 10

  • Long-Term Deformation Properties of a Carbon-Fiber-Reinforced Alkali-Activated Cement Composite
    R Gailitis, J Sliseris, K Korniejenko, J Mikuła, M Łach, L Pakrastins, ...
    Mechanics of Composite Materials 56 (1), 85-92 2020
    Citations: 9

  • Long-term properties of different fiber reinforcement effect on fly ash-based geopolymer composite
    R Gailitis, A Sprince, T Kozlovskis, L Radina, L Pakrastins, N Vatin
    Crystals 11 (7), 760 2021
    Citations: 7

  • Comparison of the long-term properties of foamed concrete and geopolymer concrete in compression
    R Gailitis, K Korniejenko, A Sprince, L Pakrastins
    AIP Conference Proceedings 2239 (1), 020012 2020
    Citations: 7

  • Drying Shrinkage Deformation Comparison Between Foam Concrete, Geopolymer Concrete, Disintegrated, and Non-disintegrated Cement Mortar
    R Gailitis, A Sprince, L Pakrastins, G Sahmenko, T Kozlovskis
    IOP Conference Series: Materials Science and Engineering 660 (1), 012036 2019
    Citations: 4

  • Mechanical properties of geopolymer concretes reinforced with waste steel fibers
    R Gailitis, K Korniejenko, M Łach, J Sliseris, J Morn, E Rodriguez, ...
    IOP Conference Series: Materials Science and Engineering 660 (1), 012007 2019
    Citations: 2

  • Tribo-Mechanical Behavior of Geopolymer Composites with Wasted Flax Fibers
    P Bazan, B Kozub, K Korniejenko, R Gailitis, A Sprince
    IOP Conference Series: Materials Science and Engineering 1190 (1), 012030 2021
    Citations: 1

  • Comparison of the Long-Term Properties in Compression of Different Size Foamed Concrete
    R Gailītis, A Sprince, L Pakrastins, G Shakhmenko, T Kozlovskis
    ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International 2019
    Citations: 1

GRANT DETAILS

2018 – 2020 Latvian Council of Science Fund (LZP-2018/2-0249) „Long-term properties of innovative cement composites in various stress-strain conditions”; senior researcher, chief executor