The annual intensive exploitation of natural resources results in the generation of substantial amounts of waste, with construction being the primary contributor. This sector is accountable for nearly half of all non-renewable resources consumed by humanity and for producing over one million construction and demolition (C&D) wastes annually. An alternative approach to managing construction and demolition wastes involves recycling and reclaiming materials on-site for environmental remediation purposes. The research aimed to explore the potential use of concrete waste as a reactive material for groundwater remediation contaminated with heavy metals (Cu, Zn) and chlorides. Concrete C&D waste was gathered from demolition sites in Warsaw, crushed to the appropriate size, and subjected to preliminary tests to assess its physical and chemical properties, including granulometric analysis, absorbability, specific surface area, and sorption capacity. Additionally, surface modification of selected concrete wastes was performed to enhance their ability to retain contaminants, alongside batch tests (kinetic and chemical equilibrium reaction) using both raw and modified materials. The kinetic studies indicated that the pseudo-second order model best fit the test results (determination coefficient ��2 value in the range of 0.72–0.99), while the chemical equilibrium studies revealed that the Langmuir, Freundlich, and Redlich–Peterson models were suitable (��2 in the range of 0.70–0.90). The findings demonstrated that C&D waste holds promise as an adsorbent material for environmental protection and remediation purposes.

The walls of steel grain silos are susceptible to buckling. The reason for this undesirable phenomenon is the vertical impact of grain stored in the silo on the walls, most often made of corrugated sheet metal with horizontal corrugations. External, vertical stiffeners make a wall strengthened and together with corrugated sheet metals create orthogonal shell structure. The procedures included in the applicable standards make it possible to estimate the buckling load capacity of the wall of a silo constructed in this way. The paper presents an example of the analysis of the buckling load capacity of the wall of a steel silo with a capacity of 700 m3. Two of the methods recommended in applicable standards were used. Numerical simulations were also performed to determine the critical level of load intensity. The analyses carried out allowed conclusions to be drawn regarding the buckling load capacity of the wall of the analysed silo.

The additive manufacturing process unique characteristics lead to the formation of structures with varying mechanical properties in different directions. However, current topology optimization methods often assume material isotropy, overlooking the anisotropy additive manufacturing materials. Hence, we propose a topology optimization method that accounts for additive manufacturing material anisotropy. We establish a local coordinate system to describe material anisotropy and integrate it into the SIMP variable density method, deriving the corresponding interpolation formula. The Kuhn–Tucker condition optimization criterion is applied to solve the problem, and an optimization program is developed. The method’s feasibility and effectiveness are validated through numerical examples, and we extensively discuss the impact of material anisotropy and printing direction on topology optimization results. Research demonstrates that our proposed method is adept at solving both isotropic and anisotropic topology optimization problems. Moreover, the material degree of anisotropy and printing direction significantly influence topology optimization outcomes. Accounting for material anisotropy, the maximum principal stress difference in optimization results obtained under different printing directions can reach 52.26%.

The construction industry is increasingly exploring alternatives to natural aggregates, driven by sustainability concerns and landfill waste reduction. Blast furnace slag, a byproduct of steel manufacturing, exemplifies this shift, serving as a substitute aggregate or concrete additive. This transition supports the circular economy principle, where yesterday’s waste transforms into today’s resources. Key to this practice is the precise determination of material parameters, which vary depending on their origin. Among these, the filtration coefficient is critical, affecting the performance of anthropogenic aggregates in construction and infrastructure. It indicates how well materials transmit water, a factor vital for structural integrity. Machine Learning (ML) presents a promising tool for estimating such parameters efficiently. This paper explores various ML techniques for predicting the filtration coefficient, comparing their effectiveness and examining the impact of the physical properties of aggregates on model accuracy. Through this approach, the paper aims to identify the most suitable methods for parameter estimation, which could enhance the durability and stability of constructions that utilize recycled materials. This research not only contributes to the field of civil engineering but also advances sustainable practices within the industry.

Construction quality, durability and service life of China Railway Track System III (CRTS III) is influenced by the performance of the self-compacting concrete (SCC) used for filling layer. In this paper, the effect of unit water consumption, sand ratio and water reducer components on working performance of SCC filling layer is studied by laboratory and field tests. Appropriate mix proportion parameters are obtained. The results indicate that unit water consumption can significantly improve the in-service performance of SCC. However, it is essential to consider both the dosage of water-reducing agents and the unit water consumption to ensure the stability of the mixture. Sand ratio of SCC is between 49% and 52% used for filling layer, which have excellent flowability and stability. It is recommended that the content of the defoamer should be 3/1 000, and the content of the air-entraining agent should be 5/1000. These research results will play an important role in improving the construction quality of SCC filling layer.

The paper analyses the effect of wind load on the dynamic responses of two domes. This is not a standard design situation, therefore static analysis alone is not sufficient. The main objective of this paper is to compare the results obtained from the application of dynamic equilibrium equations and those obtained from static analysis. The authors wanted to determine the sensitivity of the domes to the wind load. Inertial forces and dynamic equilibrium equations were taken into account in the calculations. The integration of the equations of motion was performed using the unconditionally stable version of Newmark’s method. Numerical calculations were performed using the author’s MES3D program. Two patterns and two heights of single-layer steel domes were considered, i.e. a low Schwedler dome and a high geodesic dome. The structural stability and damping capacity of the domes were compared. The analysis includes a modal study to determine the natural frequencies and their corresponding vibration modes. Then, the displacements and accelerations of the keystone of both domes were assessed.

To solve the problem of conflicting objectives in project management in the construction industry and comply with China’s energy-saving and carbon reduction policies in the construction industry, this study introduces carbon emission conditions into a multi-objective model and designs an optimization model for project duration cost quality resources. On the basis of the mixed shuffled frog leaping algorithm, this study applies an improved encoding method, a target anchoring mixed initialization operator based on heuristic information, a design constraint handling operator, discrete jumping optimization rules, and local mining of individuals in external memory for mixing and optimization, to obtain the final multi-objective optimization solution method. The research results indicated that after the performance dimension was improved, the research method could still maintain stable and superior performance. The average fitness values of the f1 function and f2 function correspond to 1.81 · 101 and 1.81 · 101, respectively. In practical engineering project management applications, compared with the mainstream mixed frog leaping algorithm based on multi-population improved firefly algorithm, the research method obtained a total project duration that was 20 days less and a total cost that was $13125 less. Only the quality level and resource balance index were slightly inferior, with decibels of 0.93% and 49. The results indicate that the research method can quickly and effectively solve multiple solutions, enhance the competitiveness of enterprises in the construction industry, and promote the green development of the construction industry.

This study comprises measurements of root systems of European hornbeam in forests located near Winiary, in the vicinity of Gdów (Wiśnickie Foothills, Poland) and near the town of Kanice (Moravia, Czech Republic). Field research included root measurements using the trench wall method conducted at a distance of approximately 1 m from the tree trunks. Tensile strength of the roots collected from both study sites and the geotechnical properties of the soil were determined in the laboratory. Based on the results of field measurements and laboratory tests, the root reinforcement was calculated using selected fibre bundle models. This study was aimed to compare root systems and mechanical properties of roots of the European hornbeam from the two sites and to compare the root reinforcement results obtained using different bundle models, taking into account different approaches to load distribution. The paper also discusses the impact of the tensile strength-strain characteristics of roots and their orientation relative to the direction of slip plane (zone) on the root reinforcement. The results of laboratory tests showed that tensile strength and elasticity of roots collected from both sites are very similar. Calculations showed that the values of root reinforcement computed using fiber bundle models are even 2.5 times smaller than those obtained from the classic Wu–Waldron model. On the other hand, the calculation results between fiber bundle models can differ by more than 2 times. It was also shown that the force-strain relationship used for calculation of root reinforcement has a significant impact on the results of the analyses, and the use of a bilinear force-strain relationship provides the results higher by approximately 10–13%.

Recently, geopolymers, a type of inorganic non-metallic cementitious materials, have attracted considerable attention as an alternative to ordinary Portland cement (OPC) and as an effective pathway to mitigate energy consumption and minimize CO2 emissions. The paper proposes a method of geopolymer design to achieve best mechanical properties of the developed material from the civil engineering perspective. Using a ternary plot, the authors selected specific proportions of geopolymer ingredients which predetermine such properties as high workability, high compressive and flexural strength. In the first stage of the research, a mixture of sand, fly ash, and alkaline activators were used to initiate the polymerization process which allowed to form specimens designated for further tests. The promising properties of geopolymers and the lack of access to OPC on the Moon have led to the consideration of using geopolymers as a building material in the construction of future extraterrestrial bases. In the second stage, simulant of the Moon regolith was utilized. The achieved results justify the claim that the proposed formulation method of geopolymers, designed for civil engineering applications, is useful both for terrestrial and extraterrestrial applications.

Abstract: To study the uniaxial compression performance of rock masses with regular dentate discontinuities, uniaxial compression tests and Particle Flow Code (PFC) numerical simulation are conducted on cement mortar specimens, and the combined effects of dip angle ��, undulation angle ��, and the number of undulating structures n of cracks on the compressive strength and crack propagation in the specimens are studied. The experimental and numerical simulation results showed that when n and �� remain unchanged, the uniaxial compressive strength of the specimens peaks at a �� of 90◦. When �� and �� remain unchanged, the compressive strength of the specimens with regular dentate discontinuities decreases with an increase in n. When n and �� remain unchanged, the compressive strength of the rock mass specimens containing dentate discontinuity decreases with an increase in ��. Almost all of the new cracks in the specimens initiate at the tip of the prefabricated cracks, and the failure characteristics of the specimens are mainly tensile fractures accompanied by a few shear fractures. When �� and n remain unchanged, and �� is 45◦–135◦, the cracks in the dentate discontinuous rock mass propagate straight along the end of the prefabricated crack and finally vertically. In addition, when �� and n remain unchanged, the crack propagation of rock mass with �� ≤ 60◦ is abundant. Moreover, when �� and �� remain unchanged and �� < 4, the crack propagation is abundant, and shear cracks are initiated at the edge of the specimens far from the prefabricated crack.