The self-compacting concrete proved to be the most revolutionary achievement of the engineering in the last 25 years. Its numerous advantages encourage an expanding research of this composite. One of the aspects of the research is its properties modification by an addition of fibres as a dispersed reinforcement. In the technology of the self-compacting concrete this problem is still not sufficiently solved. The technology of the self-compacting concrete is a difficult subject due to a large “sensitivity” of the composite on any qualitative and quantitative variation of mix components. An increase of a fibre content in a volume of the self-compacting concrete enhances properties of a hardened composite and on the other hand deteriorates its properties during the forming stage. The paper presents results of experiments on an influence of polypropylene fibres on selected properties of the self-compacting concrete. It is concluded, that a small addition of the fibres does not evoke any change in rheological properties of the concrete mix. Only a small disturbation of self-deaeration was observed leading to a small increase of concrete porosity and water absorption. The fibres decreased the concrete shrinkage, increased water tightness and did not cause any decrease of compressive strength.

Durability of engineering structures depends on the structure itself and environmental conditions. Aggressive substances can penetrate concrete matrix causing chemical degradation of material skeleton. At the same time the material is exposed to mechanical exertion which contributes to additional deterioration. This work attempts to analyze chemo-mechanical degradation of concrete from phenomenological point of view using numerical simulation. Diffusion of corrosive species was determined through local diffusion parameters and balance equations with sources and outflows prescribed by stoichiometry of chemical equations and reaction extent constant. Degradation of concrete was described with use of an additive scalar damage parameter adopting adequate evolution equations. The cellular automata method used is shown to be an effective calculation method. Contour lines of species concentration and partial damage parameter values were obtained using numerical simulation of the processes in 2D space. As expected, progressive degradation of concrete decreased bearing capacity of the RC section. Numerical simulation of residual cross-section strength was obtained by use of short-time destructive loading tests.

Metakaolin (ASTRA MK 40) is a puzzolanic addition for concrete. Most commonly used as a partial Portland-cement replacement. This thesis is based on Portlandcomposite cement CEM II/B-M (V-LL) 32.5R. Concrete with added metakaolin has been made in three batches – replacing 5, 10 and 15% of cement weight. The material has been tested thoroughly. After measures have been taken the metakaolin decreases absorbility of concrete, increases flexural and compressive strength in 28 day. It turns out concrete strenghtened with metakaolin is not frost resistant.

The paper presents results of compressive strength examination and loss of compressive strength after 34 freezing-thawing cycles for concrete with 75% volumetric quantity of recycled concrete aggregate in whole aggregate composition. Recycled aggregate was prepared by crushing of parent concrete produced earlier in a laboratory. Results show that high quality of recycled concrete comparable to the quality of similar concretes made from natural aggregate can be achieved. However, better results are obtained when carbonated aggregate is used. Final compressive strength of concrete with such type of aggregate was higher at the level of 16–23% comparing to series with unmodified recycled aggregate. Freeze-thaw resistance, expressed as the compressive strength loss, was also better in series of concrete with carbonated aggregate. That type of concrete showed only 13–21% loss in compressive strength in contrast to 26–44% obtained for series with unmodified concrete aggregate.

The work deals with the problem of dynamics of bodies made of smart materials in which a characteristic, deterministic and microstructural construction has an influence on the macroscopic properties of the entire system. In particular, the subject of the analysis is the annular plate made of a material with functionally graded properties (FGM). On the microstructural level the structure is constructed from two materials. In the circular direction the structure is periodic. In the radial direction the averaged properties of the structure are functionally variable. The study examined the issue of forced damped vibration. The starting point of discussion is the equation of motion of a thin plate based on Kirchhoff theory. Recently, the outcome of the modeling has been obtained as a partial differential equation for the unknown slowly varying function w⁰. This equation, as opposed to output equations of motion with discontinuous and highly oscillating coefficients, has smooth slowly varying coefficients. Hence, they can be solved easily by numerical methods because of its slowly varying coefficient. Moreover, the study shows the exemplary solutions of model equations for the asymptotic model. There is determined the form of the first symmetrical mode shapes for a sample set task parameters and selected the initial-boundary conditions.

The article treats about the problems connected with thermomodernization of buildings, especially its cost effectiveness associated with the technical condition of the object. For the technical evaluation it was used methodology in the preparation of energy certification of buildings and energy audits of buildings.

The work is treating about the results of the survey of the fly ash to clay and his influence selected on physical and mechanical qualities of get composite. The survey were done on samples where contents of the fly ash in the attitude to the clay hesitated from 10–30%. Samples were subjected to examinations of determining the contraction of the drying, determining the density and mass, the compressive strength and the resistance to cutting. Final results of the survey obtained that the rise in the content of the fly ash is having a positive effect to physical qualities, negatively on mechanical qualities. Examined physical and mechanical qualities should take into account at design and structural buildings works associated with raising of buildings from clay.

This paper is dedicated to the critical condition of steel structure connections of the recently built industrial hall. It presents results of connection analysis for steal columns dedicated to metal-glass fasade.

This paper contains the criteria of layer identification in subsoil structures. First of all, the definition of geotechnical layer and basic method for its identification has been explain for better understanding the presented problem. Next, the categories of geotechnical layers considering the geological and the geotechnical criteria were described. Finally the boundaries of layers were proposed for Warsaw University of Life Sciences (WULS) Campus and Stegny experimental field in Warsaw. This was obtained from CPT and DMT interpretation test results.

Fines content differentiates the behavior of soils which from classification point of view are between cohesive and cohesionless and therefore are perceived as the transistional soils and difficult to describe. The paper presents test results of 5 granular soils of various fines content ranging from 10 to 97%. Consolidation and compressibility characteristics were considered. Analysis of test results made possible formulation of conclusions concerning tendencies in change of compressibility characteristics with fines content change.