This paper investigates the composition of biological self-healing agent based on its impact material characteristics concrete. A direct addition – a mixture bacterial spores and nutrients into concrete matrix has been investigated by many studies in recent decades. Under certain conditions, applied microorganisms proved to be able produce CaCO3, researchers used this biocalcification process autonomously seal microcracks Thus, bio-based could potentially heal itself lead more durable...

This paper is focused on concrete with admixture of rubber powder, generally called crumb (CRC). The inspiration was found in Arizona, where one the first CRCs has been created. However, Arizona completely different climates than Central Europe. Could we use construction applications European climate too? evaluates influence powder material characteristics and durability CRC. various contents fine coarse were compared. tested parameters slump, air content, permeability, resistance to water...

Ultra-high performance concretes (UHPC) are characterized by high tensile and compressive strength. The strength is achieved providing well-graded grain-size distribution curve utilization of microfillers. dense structure UHPC provides low permeability, which increases resistance high-performance concrete to aggressive chemical solutions or freeze-thaw cycling. Both these features positively affect the possibilities for outdoor structures. paper presents first findings comprehensive research...

Despite limited knowledge on the proliferation of bacteria incorporated in concretes as a self-healing agent, there are efforts to standardize such technology. Proper mathematical models could potentially assist design composites and enable harness bacterially-induced calcite precipitation (BICP) more efficiently. Here, we employed Monod's model reproduce experimentally measured growth curves for Bacillus pseudofirmus, strain resistant alkaline environment present cementitious composites....

The paper describes an experimental program focused on the research of high performance concrete with partial replacement cement by fly ash. Four mixtures were investigated: reference mixture and 10 %, 20 % 30 weight replaced In first stage, effect was observed. second phase aimed at influence homogenization process for selected 30% properties. analysis macroscopic properties followed compressive strength, elastic modulus depth penetration water under pressure. Microscopic concentrated study...

Mechanical parameters of cementitious composites are primarily determined by the composition cement matrix. In case high performance concrete (HPC), high-quality compounds and increased amounts exploited to obtain best possible properties material. As these components expensive, aim is use them with maximum efficiency. With optimized procedure homogenization compounds, can be improved without changing mix. Several mixing procedures were applied a selected HPC Compressive flexural strength...

The paper presents the results of static and dynamic modulus elasticity measurements that were conducted on high-performance concretes with partial replacement cement by supplementary cementitious materials (SCM). Metakaolin, microsilica fly ash used as SCM, levels 10 %, 20 % 30 weight. tests cylindrical samples 100 mm in diameter 200 height. Dynamic was measured at age 1, 3, 7, 14, 21 28 days use non-destructive ultrasound pulse method. Static determined destructive compression test....

The mechanical properties of a cementitious composite are strongly affected by interfacial transition zone (ITZ) between the matrix and aggregates, mainly its strength thickness. A micromechanical model based on Mori-Tanaka scheme coupled with an estimation deviatoric stress in ITZ was developed for evaluation effect selected secondary materials (SCMs – silica fume, fly ash metakaolin) high-strength concrete (HSC). validated means comparison predicted thickness direct measurements performed...

The paper presents experimental study of load-deflection behavior anchorage areas in the steel-concrete composite structure under extreme longitudinal shear load. Such a situation has to be considered for example containments nuclear power plants lined with steel plate on inside. For two studied arrangements elements, no tears liner were observed. Failure occurred either concrete or elements. Load-deflection diagrams applicable further numerical analyses obtained.

Containment is the last barrier protecting environment from contamination in case of serious accident nuclear power plant. Steel liner often used to guarantee leaktightness concrete containment and therefore design must be done with utmost care. Several methods are practice anchor plate wall, differing layout type anchorage elements used. The system ensure full connection buckling tearing have prevented. objective research was determine behavior typical details steel subjected axial shear...

Over the past decades, efficiency of silicate-based surface treatment agents, in other words, sealers, concrete systems has been widely investigated. The technology protects cementitious against penetration undesirable substances. Nevertheless, understanding several aspects concerning sealers is not entirely clear. This paper studies action mechanism selected silicates such as potassium, sodium, lithium water glasses, and colloidal silica. effectiveness used terms absorption reduction,...

Abstract The degradation processes in surface layers of cementitious composites can be mitigated either by optimizing the material or applying protection. In this paper, effect lithium silicate (LS) sealer is investigated. Water absorbance studied on standard cement mortar; frost resistance and porosity are examined two types concrete (C30/37 C50/60). results indicate that LS impregnation improves water only slightly case short exposure to water; was reduced 15–25% immediately after sealer,...

Abstract The subject of the research is a concrete with partial replacement cement an increased amount ground granulated blast furnace slag to reduce heat release for structures Akkuyu Nuclear Power Plant (Iskenderun, Turkey). was tested release, compressive strength and shrinkage. Several mixes by from «Iskenderun Demir ve Çelik A.Ş.» were used testing. reduced up 50 % loss not more than 36 %. This result increase in content mixed binder (cement + slag) decrease content. optimal 25 There...

Increased requirements on environmentally friendly construction process of road structures with emphasis economical savings and durability roadways lead to search for new material solutions pavements. Roller-compacted concrete (RCC) is an ordinary poured compacted machines typically used placement asphalt pavement layers. Its main advantage relatively good ratio between mechanical properties overall costs during construction, operation maintenance phases. After extensive literature review...