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Extrusion-based three-dimensional concrete printing (3DCP) produces a periodic layer structure that renders the printed material inherently anisotropic. Quantifying this anisotropy non-destructively is essential for in-situ quality assurance. In this study, impact-echo (IE) signals were acquired on 52 laboratory-produced 3D-printed mortar prisms in two layer orientations: K (layers perpendicular to the test surface) and R (layers parallel to the test surface). Three IE wave types per specimen - longitudinal (FL), ...

Non-destructive testing (NDT) of 3D-printed concrete is challenging due to complex geometries and layer-dependent material heterogeneity. Photogrammetry captures surface geometry, but its outputs cannot be directly linked to NDT values. This study presents a workflow that integrates photogrammetric models with rebound hammer measurements and applies radial basis function (RBF) interpolation to visualize near-surface strength. Each measurement point is matched to its 3D coordinates on the mesh, enabling consistent ...

Different forms and combinations of degradation attacks cause the damage of concrete and reinforced concrete structures. Among the most usual belong ingress of chlorides and carbonation that influence the quality of the concrete and also affect its ability to protect reinforcement. The resistance of concrete against the mentioned attacks is given also by other surrounding conditions, like temperature, mechanical load, etc. In this paper, experimental findings are presented focused on the investigation of the effec...

Durability and reliability of concrete structures is influenced by different forms and combinations of attacks such as environmental, mechanical, chemical and/or electrochemical. Among them the damage due to reinforcement corrosion is a rather crucial one and rather often is governed by the presence of chlorides on the surface of the steel. To assess and/or predict this complex effect causing a specific type of concrete damages, both the experimental and modelling methods have to be utilized. As a part of large ex...

With the development of concrete technology, the polypropylene fibers have been extensively used in concrete structures for property and durability enhancement. The polypropylene fibers have significantly low cost compared to steel, the use of macro polypropylene fiber could achieve a similar level of reinforcement in concrete at a half price of using steel. The article focuses on the influence of polypropylene fibres of concrete properities. The aim is to compare the basic material properties of concretes with th...

The leading material property of concrete that has the greatest influence on its service life and therefore sustainability depends primarily on the method of loading of the structure and the characteristics of the environment in which it is supposed to fulfill its function. The motivation of this study is the prediction of chloride ingress in time into the concrete specimens using a 1D analytical model implemented in probabilistic software FReET-D. This estimation is directly used for prediction of the time necess...

The diagnosis of existing structures determines the current state of the selected object. In order to diagnose structures as accurately as possible, it is necessary to choose reliable and effective survey methods, which are used to achieve objective and reliable results. When choosing destructive physical analysis, which includes, for example, concrete cores, accurate and appropriate results are obtained. However, the disadvantage of these methods is that they result in irreversible damage to the structure. For th...

Among its activities, the construction industry has a significant impact on the environment. In recent years, therefore, emphasis has been placed on the sustainability of building structures and materials, and ways and means are being sought to achieve this. Specifically, it is about reducing emissions and using the waste produced by recycling materials, e.g. aggregate. The motivation for using recycled aggregates is also to reduce dependence on natural resources, which are declining. The article deals with the as...

The structural design of concrete structures needs to result in qualities ensuring structural safety and serviceability, together with durability, robustness, sustainability and resilience. Due to this, the effects of mechanical load, environmental load and even social coherence need to be reflected and included in the formulation of limit states. This is a complex matter involving the time factor, service life, degradation effects, modelling, probability analyses, limit states, costs and other phenomena, and it i...

Concrete is one of the most important and useful materials in the construction sector, which, unfortunately, has an adverse impact on the environment. It is evident that correct procedures for designing concrete structures need to be created. The sustainability approach is a key conceptual principle to be considered in cement and concrete production all around the world because about 7 % of global CO2 emissions are produced by cement manufacturing. An indicator expressing quality, with regard to sustainability, is...