<abstract xmlns="http://www.w3.org/1999/xhtml">

The paper aims to present the basic properties of cold mixes in terms of the type of binding agent. In the theoretical part of the article, a description of the technology for producing cold recycled mixtures and the types of road binders used in cold mixtures was presented. The research part presents the experimental design, and gives an overview of the research methodology used to assess the impact of the type of binding agent. Mixes differing in type and binder content were designed. During the laboratory work, mixtures were prepared with cement binder (CBGM), cement-modified polymer binder (CBGM+P), mineral-cement-emulsion modified with polymer binder (BE-RCM+P), and mineral-cement mixtures with foamed bitumen modified with polymer binder (FB-RCM+P). The project aimed to produce cold mixtures with variations in the type and amount of binder used. The mixtures were prepared using cold mix technology. The effect of the binder on the cold mix properties was studied. During the research, the following properties were examined: void content (Vm), indirect tensile strength (ITS), resistance to water damage (TSR), stiffness modulus using the IT-CY method and an axial compressive strength. On the basis of the research carried out, an analysis was made. Among other things, the polymer modification was found to have a positive effect on the void content of the mix. The research carried out in this way made it possible to show the influence of the binder on the properties of cold mixes.
</abstract>

Influence of the Binder on the Properties of Cold Mixtures

<abstract xmlns="http://www.w3.org/1999/xhtml">

Friction stir welding (FSW) is a modern technology for joining various metals, which has already undergone many laboratory tests, but still requires the development of numerical models. Author of the paper decided to summarize the current state of scientific knowledge regarding the modelling of the FSW process using the finite element method (FEM) and showed the main directions of development of numerical research on this process. Very advanced models are a combination of solid mechanics and fluid dynamics, but they often require expanding the computing environment with its own subroutines, as well as calibration and validation of some material parameter and constants occurring e.g. in the heat generation and heat flow laws. The Author of the paper proposed his own, simplified model, based on the computational solid mechanics and Lagrangian formulation. The model turned out to be an effective tool to reproduce stress and temperature fields during the FSW process.
</abstract>

Numerical Analysis of Stress and Temperature in the Friction Stir Welding (FSW) Process of Steel

<abstract xmlns="http://www.w3.org/1999/xhtml">

The sway of tall buildings in the wind is a fascinating and crucial consideration for professionals in the structural, environmental, and architectural fields. Previous research has related wind pressure to building load and natural ventilation, but few studies have looked at how building dimensions impact wind pressure. This study examined wind pressure coefficient distributions within and around several rectangular-shaped high-rise buildings using experimental and computational fluid dynamics approaches. The height-to-width ratio and height-to-thickness (length) ratio significantly affected the wind characteristics of buildings. The windward side with a narrower width experienced higher wind pressure, while the larger leeward side experienced a more negative wind effect. Wind pressure coefficient distribution varies with decrease in the side ratio. However, the side ratio of the building had little influence on positive wind pressure at wind incidence angle of 0°, which was a surprising finding. Pressure coefficients were evaluated and compared with standards by measuring fluctuating wind pressures at pressure points on all surfaces of models, and then calculating the mean, maximum, minimum, and r.m.s. values of these coefficients.
</abstract>

CFD and Experimental Investigation of the Impact of Dimensional Modifications on Wind Pressure Coefficient Distribution

<abstract xmlns="http://www.w3.org/1999/xhtml">

The article presents the influence of pumice, trass and chalcedonite powder on rheological properties of cement pastes. Cement was being replaced both of additions 10% or 20% by mass and combination of pumice or trass and chalcedonite powder in the amount 5% or 10% of each of them. The main purpose of the publication was to assess the effects of chalcedonite powder with selected mineral additions in terms of rheological properties and compare them with the results obtained for pastes modified with only one of the additions. In each case, the additive or combination of additives introduced into the paste reduced the flow, compared to the result of paste without additive(s). Rheological properties varied depending on type and amount of additive(s).
</abstract>

Rheological Properties of Cement Pastes Modified with Pumice, Trass and Chalcedonite Powder

<abstract xmlns="http://www.w3.org/1999/xhtml">

Joint sealants produced on the basis of modified bitumen are an effective mean for protection of expansion joints on bridges and for repair of cracks in various road surfaces. A comparative study was performed to evaluate seven hot-applied joint sealants obtained commercially and three joint sealants produced in laboratory conditions with different contents of highly modified asphalt binder (40 to 100%). The basic properties of the joint sealants and asphalt binders were evaluated, including penetration, softening point, breaking point and elastic recovery. Additionally, Fourier infrared spectroscopy (FTIR) method was used to evaluate the chemical composition of the asphalt binders. The variability of the basic properties of joint sealants was estimated in the range from -77.1% to 43.6% in relation to the base asphalt binder. It has been established that the addition of crumb rubber, hydrated lime and rapeseed oil may be viable in controlling the parameters of the joint sealants.
</abstract>

The Comparative Studies of the Properties of Joint Sealants Produced by Manufacturers and in Laboratory Conditions with the Use of Highly Modified Bitumen

<abstract xmlns="http://www.w3.org/1999/xhtml">

In cold-formed thin-walled cross-sections, complex phenomena, related to local and distortional buckling of slender walls containing edge fold stiffeners, occur. In order to determine the design resistance of such a cross-section in the post-buckling range, it is necessary to determine the critical stress of local buckling for individual walls. On this basis, the corresponding effective widths are determined. Subsequently, the distortional buckling effect is taken into account, typically by reducing the thickness of the substitute cross-section of the stiffener.
The paper presents approximation formulas of plate buckling coefficients (k*) that are used to calculate critical local buckling stress for technically crucial stress distributions. The full range of variation of the index of elastic fixity of the longitudinal edge of the thin-walled cross-section was considered. The coefficients were determined for a more accurate, relative to Eurocode 3, computational model. Both the effect of reciprocal elastic restraint of component walls of the cross-section and the effect of longitudinal stress variation, which occurs in transversely bent beams, were taken into account.
</abstract>

Local Buckling of One-Side Elastically Restrained Thin-Walled Cross-Section Wall Under Longitudinal Stress Variation

<abstract xmlns="http://www.w3.org/1999/xhtml">

An important factor threatening global security is climate change and its impact on changing rainfall patterns and seasonal temperature variability. For this reason, farmers and crop scientists are striving to detect plant stress as soon as possible and introduce preventive measures so that key decisions in maintaining plant health are made in a timely way. Currently, multispectral images acquired from UAVs (Unmanned Aerial Vehicles) make it possible to provide objective and reliable information related to the state of agro-ecosystems, the dynamics of changes occurring on them and the monitoring of natural resources in a rapid and non-contact method. In the present study, the suitability of low-altitude multispectral imaging for proper stress detection in plants was assessed. The botanical garden in Kielce, a site with a high biodiversity of plant specimens, was chosen as the testing ground. In this study, four spectral indexes maps were analysed in the form of: NDVI (Normalized Difference Vegetation Index), NDRE (Normalized Difference Red-Edge Index), GNDVI (Green Normalized Difference Vegetation Index) and the less frequently used PSRI (Plant Senescence Reflectance Index) for the assessment of plant health. PSRI values > 0.50 clearly identified areas of high stress, in contrast to the other spectral indices analysed in this study. The study confirmed the suitability of the PSRI for conducting monitoring activities in areas with varying crop characteristics in an efficient and rapid approach.
</abstract>

Assessment of the Suitability of Spectral Indices for Detecting Areas of Increased Stress among Plants – A Case Study of the Botanical Garden in Kielce

<abstract xmlns="http://www.w3.org/1999/xhtml">

The objective of this study is to assess the threat of contaminating groundwater originating from the first exploitative aquifer level in the municipality of Bodzentyn within the Świętokrzyskie Voivodship. The analysis included 23 representative groundwater intakes from MHP 816 Bodzentyn sheet. The various potential sources of groundwater contamination were identified. The intrinsic vulnerability of the first aquifer to contamination and the water recharge area were determined. In the results intakes potentially threatened by anthropogenic pollution were indicated. Providing information on the potential risks of groundwater contamination will help better plan environmental and decision-making activities in this area. The results can serve as a basis for policy development, land use and sustainable resource management in the municipality of Bodzentyn.
</abstract>

Groundwater Contamination Risk Assessment in the First Exploitable Aquifer Stratum within Bodzentyn Municipality, Świętokrzyskie Voivodeship

AHEAD OF PRINT

Volume 16 (2024): Issue 1 (March 2024)

Volume 15 (2023): Issue 4 (December 2023)

Volume 15 (2023): Issue 3 (September 2023)

Volume 15 (2023): Issue 2 (June 2023)

Volume 15 (2023): Issue 1 (March 2023)

Volume 14 (2022): Issue 4 (December 2022)

Volume 14 (2022): Issue 3 (September 2022)

Volume 14 (2022): Issue 2 (June 2022)

Volume 14 (2022): Issue 1 (March 2022)

Volume 13 (2021): Issue 4 (December 2021)

Volume 13 (2021): Issue 3 (September 2021)

Volume 13 (2021): Issue 2 (June 2021)

Volume 13 (2021): Issue 1 (March 2021)

Volume 12 (2020): Issue 4 (December 2020)

Volume 12 (2020): Issue 3 (September 2020)

Volume 12 (2020): Issue 2 (June 2020)

Volume 12 (2020): Issue 1 (March 2020)

Structure and Environment

ABOUT THE JOURNAL   Structure and Environment, a quarterly journal, has been published by the Kielce University of Technology since 2009.  It uses Editorial Manager for online submission and manuscript tracking https://www.editorialmanager.com/sae/default1.aspx. It is recommended to provide ORCID codes for each co-author. Papers are published in English and are assigned digital object identifier DOI:10.30540/sae.  Structure and Environment is an Open Access journal that allows unrestricted and free-of-charge access to its content at www.sae.tu.kielce.pl and www.sciendo.com./journal/SAE.  Peer-review process:   The editor appoints two reviewers whose names are hidden from the authors.  Manuscript evaluations are assigned one of four outcomes:　Accept, Minor Revisions, Major Revisions, and Reject. Manuscripts with Minor Revision" do not require a second review. Manuscripts receiving a Major Revision evaluation must be subjected to a second review. If the author(s) failed to make satisfactory changes, the manuscript is rejected Rejected manuscripts are given no further consideration.  The editor decides whether the paper fulfill all requirements i.e. formal and scientific.  As soon as the publication appears in electronic forms on the Internet there is no possibility to change the content of the article.   The authors do not bear any publication costs.　   In 2023, Structure and Environment was entered into the Polish Ministry of Education and Science Journals list with a score of 70 points. Committed to ensuring the high quality of our publications.  The content of the quarterly is indexed by more 10 ten bibliographic databases and made available in the collection of peer-reviewed interdisciplinary scientific articles, e-Publikacje Nauki Polskiej.　  Format of the journal – electronic forme- ISSN: 2657 – 6902  ISSN: 2081 - 1500DOI: 10.30540/sae/  Journal Metrics:  Index Copernicus Value (IVC) 2022 = 100  The Polish Ministry of Education and Science 2021 = 70 pts   Archiving  Sciendo archives the contents of this journal in Portico - digital long-term preservation service of scholarly books, journals and collections.  Plagiarism Policy  The editorial board is participating in a growing community of Similarity Check System's users in order to ensure that the content published is original and trustworthy. Similarity Check is a medium that allows for comprehensive manuscripts screening, aimed to eliminate plagiarism and provide a high standard and quality peer-review process. 