This paper investigates the potential use of coked sands, a byproduct of the thermal processing (pyrolysis) of oil sands, in asphalt concrete mixtures. After pyrolysis extracts the oil from the oil sand, the remaining mineral part becomes coked and changes color to black as solid waste, resulting in a coating of biochar. The coked sand’s X-ray phase analysis (XRD) shows peaks at 4.2564, 3.6749, 3.3768, 3.2380, 3.1903, 2.4581, 2.2800, and 2.2365. Quartz, aluminosilicates, metal oxides, and possibly even carbonates make up the sand’s mineral makeup, as indicated by these peaks. One way to use them is in road construction. In this study, we substituted sand screenings with coked sand in amounts of 5%, 7%, and 10% to examine its impact on the composition of asphalt concrete. This study used 5% paving bitumen (BND 70/100) as a binder for asphalt mineral materials of varying sizes. It concludes that using coked sand to produce asphalt concrete can save 5–10% of sand screenings. The test results showed that adding 5% and 7% of coked sand increases the compressive strength at 50 °C by 8% and 31%, respectively. Adding 10% of coked sand does not increase the strength and actually makes it weaker. The results of the asphalt concrete samples meet type B grade 1 standards of ST RK 1225-2019.

Three-dimensional subsurface mapping is increasingly used to turn ground investigation evidence into continuous 3D models of soil layers and geotechnical properties that support decisions in ground characterization. This review summarizes the current state of 3D mapping for geotechnical purposes using a citation-guided selection based on Litmaps, resulting in a curated set of 27 studies. The literature is organized into a taxonomy aligned with the Litmaps clustering and grouped into six approach families: implicit or potential-field structural modeling, voxel models and voxel workflows, uncertainty-oriented stochastic and inversion or segmentation approaches, automation and urban-scale pipelines, geophysics-driven 3D modeling, and interoperability and engineering delivery. The comparative analysis shows that practical outcomes depend not only on the final model type but also on workflow design, including data harmonization, modeling rules, and update procedures. Credibility depends on validation methods matched to the target variable and on uncertainty outputs that show where the model is strongly supported by data and where it relies on extrapolation. The review also highlights model comparability as a key operational issue, since mismatches between neighboring models can arise from inconsistent conceptual rules, discretization differences, uneven data density, and asymmetric auxiliary constraints. The paper concludes with an applicability framework, including a decision flow and compact criteria, to guide selection, evaluation, and reporting of decision-grade 3D subsurface mapping products for geotechnical ground characterization.

This study develops and assesses a hydrophobized fly ash mineral powder as a filler for dense fine-graded asphalt mixtures in Kazakhstan. Fly ash from a local TPP was dry co-milled with a stearate-based modifier to yield a free-flowing, hydrophobic powder that meets the national limits for moisture, porosity, and gradation. SEM shows cenospheres and broken shells partially armored by adherent fines, suggesting an increased micro-roughness and potential sites for binder–filler bonding. Three mixes were produced: a carbonate reference and two fly ash variants, all designed at the same optimum binder content. Compared with the reference, fly ash fillers delivered a markedly higher compressive strength (up to about five times at 20 °C), improved adhesion, and high internal friction, while the mixture density rutting resistance was essentially unchanged. Water resistance indices remained high and stable despite only modest changes in water saturation, and crack resistance improved, especially for the dry ash mixture. The convergence of microstructural, physicochemical, and mechanical results shows that surface-engineered fly ash from a Kazakhstani TPP can technically replace natural carbonate filler while enhancing durability-critical performance and supporting the more resource-efficient use of industrial by-products in pavements.