This paper outlines effect of the mix composition on mechanical properties high-strength concrete based aggregate size like in Reactive Powder Concrete (RPC) but without fiber reinforcement.The main purpose which guided authors choosing proportion water and superplasticizer (SP) was to achieve a similar consistency test slump for various mix.Test results 3 groups superplasticizers, designated as D -with chemical base -acrylic polymer, V -polycarboxylate ether, P -modified polycarboxylates,...

The paper presents experimental studies on the influence of a simultaneous, appropriately proportioned combination microsilica and fly ash additives physical mechanical properties ultra-high-performance concretes (UHPCs). Concrete mixtures with addition in amount 6.7–14.7% 8.3–26.7% were analyzed, assuming constant content cement, water superplasticizer. Experimental carried out regarding consistency fresh concrete compressive strength, flexural tensile splitting secant modulus elasticity,...

The main purpose of the study was to propose a modification Larrard’s formula for both design and compressive-strength evaluation ultra-high-performance concrete. proposed consisted introduction new parameters into original that allowed it consider amount binders fine-grained aggregates, reinforcing fibers, specimen shape size, curing time, reinterpretation water/cement ratio. verified based on comparative analysis with results our own experimental studies taken from literature. A very good...

In this work, we present an analysis of natural fine aggregates’ influence on the properties ultra-high-strength concrete. The reference concrete mix was made sand with addition fly ash and microsilica. It assumed to obtain a very high strength without fibers special curing conditions, ensuring required workability corresponding consistency class S3. modified by replacing granite basalt aggregate in same fractions. Five series mixes CEM I 52.5R cement were tested. Experimental investigations...

The reduction of carbon dioxide emissions, introduced by the European Union, opened possibility conducting experimental works on a new generation materials—ecological and environmentally friendly ones. Such materials include those which combine raw natural resources with waste subject to disposal. objective performed investigations was an assessment influence fly ashes selected parameters building materials. paper proposes method enrichment clay ash, would lead neutralization heavy metals in...

Abstract The paper presents integrated effects of concrete samples size and fibers amount on compressive strength high‐ ultra‐high concretes based reactive powders. Ready to use the self ‐ compacting mix high‐performance concrete, was applied. main aim work determine correlation coefficients for cubic including ratio. article results experimental tests 3 sizes samples, i.e. 40, 100, 150 mm, with application steel ratio 0%, 2%, 4% each sample size. Concrete air content cone flow test studies...

Pedunculate oak (Quercus robur.L) is a European tree species highly sensitive to drought.If declining symptoms appear they are often detectable at the crown (such as dieback) enabling monitoring using aerial images and remote sensing methods.Here, we analyzed impact of short long-term drought on oaks located in western Poland, between years 2014 2017.We used both leaf nitrogen (N) phosphorus (P) concentrations measured laboratory, collected range 460-880 nm machine learning techniques...

In order to improve the performance of cement mortar (Portland cement), it was enriched with triclosan, hypochlorous acid, silver nanoparticles and graphene oxide. Cement is used, among other things, fill gaps between tiles building porcelain stoneware. A number structural, mechanical biological tests were carried out. The structural included microscopic analysis contact angle, reflectance IR spectra, while involved static bending compression testing. These showed that additions oxide acid...

The purpose of this work was to develop a substitute material model for the analysis reinforced concrete structures. This paper presents proposals solve problem limited calculation time, both perform simulation models and effective numerical or analytical analyses structural elements in order achieve results consistent with experimental results. Achieving aim is conditional upon determination parameters, taking into account type structure, system reinforcement, static strength-deformation...

Work issues concern the safety of construction in relation to hazards arising from explosion explosive charge located inside building. The algorithms proposed paper for determining parameters overpressure wave resulting detonation clustered charges, determine basis numerical simulation analyzes. Determination maximum value peak pressure on forehead an internal is presented reflected analysis. Changeability time action describes phase only. analysis load caused by was carried out under...

Abstract This paper outlines a method of determining the deformation and strength parameters for hypothetical, homogeneous, substitute material which approximates properties heterogeneous materials in reinforced concrete elements. The model creates reference model, static - were modified on basis homogenizing function with homogenization coefficient assumed as effective reinforcement ratio structural results comparative analysis numerical models using hypothetical experimental statically...

The aim of the study is to assess usefulness using granite aggregate make very-high-strength concrete. paper presents a comparative analysis results that are obtained for three types concrete mixtures. main components analysed concretes sand or aggregates and cement CEM I 52,5 with addition microsilica fly ash. first, basic mixture made as aggregate. assumption obtain compressive strength not lower than 100 MPa in normal conditions curing water. Furthermore, fractions up 2 mm semi-liquid...

The focus of this work is on comparison the compression strength cementitious - limestone composite samples made according to different recipes. study includes results own experimental research high performance composites as well an analytical calculations mixture proportioning and designed compressive strength. Mixture based formulas Funk Dinger was determined. In following step modified Larrard designed. Three test with dimensions 100 x mm were for each recipe B1, B2, B3. Information...

Abstract The study was conducted to perform a comparative analysis of the mechanical properties wood samples derived from oaks in Krotoszyn Plateau, which depend on health state trees. Strength parameters oak were calculated for selected diseased and healthy trees (according Roloff classification). by modified method described standard Polish Norm PN EN 408+ A1: 2012. For testing, prior selection showed that more compared with those did not fulfil requirements. According used, average...

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The paper presents the method of determining impact an external explosion on construction barriers, taking into account angle shock wave. For presented two variants analysis, i.e. for load placed at a distance 5 and 10 m from barrier, initial pressure reflected wave, duration overpressure course variability over time were determined. assumed parameters barrier blast load, values determined, incidence reflection. Additionally, comparative analysis proposed with other methods available in...