Keywords: durability

Mechanical and durability performance of concrete incorporating waste glass powder and ldpe in saline environments

https://doi.org/10.58224/2618-7183-2026-9-3-8
Abstract
The depletion of natural sand reserves and the accumulation of plastic and glass waste necessitate sustainable alternatives for concrete production, particularly for infrastructure in aggressive environments such as the Dead Sea region. This study evaluates the mechanical and durability performance of concrete incorporating waste glass powder and Low-Density Polyethylene (LDPE) granules as partial replacements for fine and Coarse aggregates. Experimental mixes included a control sample and variations with 10% glass powder combined with 5%, 10%, and 15% LDPE, subjected to standard curing and 3-month immersion in a 5% NaCl + 5% Na₂SO₄ saline solution. Mechanical properties were assessed through compressive and tensile strength tests, ultrasonic pulse velocity, and strain gauge measurements, complemented by microstructural analysis using SEM and XRF, and numerical validation via ABAQUS Concrete Damage Plasticity (CDP) simulations. Results indicated that the mix containing 10% GP and 5% LDPE showed optimal performance, reached a compressive strength of 46.63 MPa , compared to 42.47 MPa for the control. Notably, after saline exposure, this optimal mix showed a 47.49% strength increase, whereas the control suffered a 13.72% reduction, attributed to the pozzolanic reaction of GP and the hydrophobic barrier effect of LDPE. Microstructural analysis confirmed reduced efflorescence (salt crystallization) and ettringite formation in modified samples, while simulations (Abaqus) validated superior stress redistribution capabilities. These findings demonstrate that combining waste glass and LDPE enhances concrete ductility and resistance to chloride and sulfate attack, offering a viable sustainable solution for infrastructure in corrosive marine environments.
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Salt spray corrosion test, hardness test, and abrasion test of nanomodified phosphate coatings

https://doi.org/10.58224/2618-7183-2026-9-1-3
Abstract
The development of new rust converter formulations is a relevant issue that contributes to increasing the competitive edge of domestic products and sustainable development of various branches of the economy. The aim of the study is to determine the corrosion resistance of various phosphate films on the metal surface when exposed to salt spray, as well as to determine hardness and resistance to abrasion (scratching).
Materials and methods: Metal rods are coated with a film using a special surface treatment with orthophosphoricacid-based rust converters. The study introduces a new experimental rust converter formulation containing a Lewis acid (or its salts) and dispersed nanopowders of oxide and other inorganic/organic complexes.
Results: Tests revealed that full-scale corrosion of metal rods treated with the experimental formulations began after 9 and 10 days, while untreated rods were showing signs of corrosion as early as on the second day. These films also demonstrated a hardness of 490 HV (modified scale of a TEMP-4 hardness tester) and withstood a maximum indenter load of 4.1 kg (measured with PROMTPP-1518) based on ISO 1518 method (scratching with a needle).
Conclusions: Based on the test results, it was concluded that the modified phosphate films exhibit high hardness and resistance to needle scratching according to ISO 1518 method, and also exhibit increased corrosion resistance to salt spray. However, the demonstrated resistance is insufficient for exposure to a salt spray chamber for 42 days.
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The production technology of high-performance ceramic stones based on the products of processing of coal dumps

https://doi.org/10.58224/2618-7183-2024-7-4-4
Abstract
The aim of the research was to study the main properties of coal dumps processing products, their impact on the quality of finished products and the development of a technology for manufacturing process of ceramic stones with high efficiency. Structural features and chemical-mineralogical composition of coal dumps processing products have been studied, their pre-fired and firing ceramic properties have been studied. The raw mass compositions were chosen based on this, along with testing of laboratory samples. The impact of different technological factors on the properties of the final products has been identified and established. The material composition and technological properties of fine, fine and medium fraction materials are shown. A basic classification of the products derived from processing of waste heaps has been conducted based on grain composition, coal component content, and mineralogical and petrographic characteristics. The optimal formulations for raw material mixtures and the manufacturing process for producing large ceramic bricks with an average density below 800 kg/m3 are described. The impact of grinding degree of the waste heap processing products and the firing temperature on the strength of the samples have been established. The incorporation of finely dispersed products from waste heap processing decreases the density and strength of the samples. It is suggested to use semi-rigid extrusion technology for molding these products. Utilizing processed coal waste materials in wall ceramics production will aid in their disposal and enhance the environmental conditions in the area. This research was conducted in Russia at Don State Technical University in Rostov-on-Don. In creating a technology for producing ceramic blocks from screenings of waste heap processing in Eastern Donbass, minimal production costs and high profitability of production are envisaged.
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