Additive manufacturing reshapes concrete construction, yet routine strength verification of printed elements still depends on destructive core sampling. This study evaluates whether standard 70 mm cubes—corrected by a single factor—can provide an equally reliable measure of in situ compressive strength. Five Portland-cement mixes, with and without ash-slag techno-mineral filler, were extruded into wall blocks on a laboratory 3D printer. For each mix, the compressive strengths of the cubes and ∅ 28 mm drilled cores were measured at 7, 14 and 28 days. The core strengths were consistently lower than the cube strengths, but their ratios remained remarkably stable: the transition coefficient clustered between 0.82 and 0.85 (mean 0.83). Ordinary least-squares regression of the pooled data produced the linear relation ${\widehat{R}}_{core}$ [MPa] = 0.97 ${\widehat{R}}_{cube}$ − 4.9, limiting the prediction error to less than 2 MPa (under 3% across the 40–300 MPa range) and outperforming more complex machine-learning models. Mixtures containing up to 30% ash-slag filler maintained structural-grade strength while reducing clinker demand, underscoring their sustainability potential. The results deliver a simple, evidence-based protocol for non-destructive strength assessment of 3D-printed concrete and provide quantitative groundwork for future standardisation of quality-control practices in additive construction.

This paper presents a review of both the research and practice regarding the latest available information on bitumen modified using polymers, among which special attention is paid to polyethylene (PE) and polypropylene (PP), both widely used to significantly improve the properties of bitumen. In this literature review, the authors concentrate on the chemical composition of modified bitumen, assessing the various approaches utilized in improving its engineering properties in paving, as well as looking at traditional additives and polymers. The latter have been shown to greatly enhance the performance characteristics and properties of bitumen. The viscoelastic behavior of polymer-modified bitumen (PMB) depends on various factors, including initial polymer structure and concentration, mixing temperature and technique, as a well as species of bitumen and its resistance to factors such as solvents and temperature fluctuations. Though an assertion can be made that both traditional additives and polymers have the potential to improve specific properties of bitumen, PMB appears to provide significant increases to the ability of the composite material to withstand a broader range of climatic conditions.