In recent years, cold atmospheric pressure plasma (CAPP) technology has received substantial attention due to its valuable properties including operational simplicity, low running cost, and environmental friendliness. Several different gases (air, nitrogen, helium, argon) techniques (corona discharge, dielectric barrier jet) can be used generate at temperature. Plasma treatment is routinely in materials science modify the surface (e.g., wettability, chemical composition, adhesion) of a wide...

Poor adhesion of synthetic macro fibers to a cementitious matrix limits their reinforcing capacity when used in fiber-reinforced composites (FRCCs). As remedy this problem, high concentrations must be incorporated into such mixtures, which makes dispersion fresh mixtures difficult achieve. Several strategies have been adopted improve bonding between and matrix, but most them cause deterioration fiber properties. In previous studies, plasma treatment polymer strengthening the fiber-matrix...

Adhesion between bitumen and aggregates has a major impact on the performance of asphalt mixes. In order to avoid stripping consequent premature failure pavement, methods assess adhesion have been developed standardised. These methods, such as frequently applied rolling bottle test defined in EN 1269-11, are based visual inspection specimens subjective evaluation. This shortcoming can be eliminated by employing image analysis that accurately consistently identifies portion aggregate covered...

This article is focused on the mechanical testing of cement-based samples containing a micronized waste marble powder used as replacement standard binders. Tested materials consisted cement CEM I 42.5 R (Radotín, Czech Republic) and three different amounts marbles (25, 50 70 wt. %). Standard bending compressive tests prismatic having dimensions equal to 40 × 160 mm were done in order reveal an influence amount flexural strength, respectively. Moreover, dynamic modulus elasticity shear...

The presented study was focused on the influence of micronized recycled a concrete sleeper mechanical properties fine-grained concrete, specifically dynamic modulus elasticity. tested material consisted cement CEM I 42.5R (Radotín), crushed bricks fraction 2-5 mm, 0-4 mm sand and 0-0.125 mm. Individual samples differed in quantity finely ground (milled at Ltd. Lavaris, Libčice – Czech Republic). Cement replaced by an amount 30, 50 70 weight percent. Testing performed beams dimensions 40 ×...

This article deals with utilization of recycled concrete in form high-speed milled powder into cement based materials. Recycled that is used as microfiller and replacement. contains results mechanical properties the pastes different amount powder. The compressive strength, flexural dynamic Young's share moduli are observed during 409 days. According to can be assumed replacement under 30 wt. % total amount. Especially strength comparable reference sample. But there some abnormalities long...

The paper deals with comparison of chosen mechanical properties cement composites reinforced by carbon microfibers. There are tested three mixtures, which different in their composition. Each sample was destructive methods to determine and physical properties. main object experiments verification an influence individual components concrete mixture on cohesion a surface fibers. Evaluation results use the best for experimental testing like change is second this paper.

The surface treatment of polypropylene microfibers by plasma processing in oxygen and argon was studied with the motivation to increase their cohesion cement matrix. By treatment, it is possible modify mechanically, chemically or a combination both. were modified using reactive ion etching system. plasma. wettability measured Packed Cell method. Furthermore, weight before after modification measured. Finally, examined scanning electron microscopy. Almost all modifications microfiber surfaces...

Asphalt mixtures often fail due to a low adhesion of bituminous binder mineral aggregate, which leads surface coarse damages like potholes and fatigue cracking. To avoid this phenomenon, different types promoters may be admixed into but new question about their effectiveness arises. This paper presents two semi-automatic methods, reliably replace the subjective assessment. Both them use digital image asphalt as an input. The first is based on gray level thresholding, while second one...

This work deals with determination of location micro fibers positions in fiber-reinforced concrete. The digital images sectioned cement-paste samples dimension equal to 40 × mm were used as an information source about the monofilaments positions. Properly acquired image high resolution allows determinate number cross sections and relate theirs coordinates any point. Optical microscope Carl Zeiss Axio Zoom.V16 camera software allowing individual shots composition examined surface was obtain...

This article presents the mechanical properties of composite materials based on recycled which differ in their composition – type materials. Dynamic modulus elasticity was monitored during first 28 days since manufacture by use non-destructive testing (resonance method). Flexural strength and compressive were determined for old specimens. The aim this to determine influence amount material resulting properties. Mixtures with 3 different microground (recycled concrete, marble powder silica...

Presented article deals with the influence of PET fiber production on bending strength cement-based composite when incorporated into fresh mortar, and comparison results 3-point 4-point test. Cement paste samples were reinforced 2 wt. % primary or recycled fibers. The test was performed prismatic dimension 40 × 160 mm. It found that fibers, compared to ones, exhibit a decrease in strength. In case tests, fibers exhibited higher than reference without any However, had lower ones. suggest...

This article discusses the possibility of recycling concrete waste using high-speed milling method. The resulting is micronize old concrete. Used was created by crushing concrete, which served as a structural for construction supporting column. Two level process used to recycle main use partial replacement commonly binder and microfillers in For this reason, properties particle size distribution, dynamic modulus elasticity, flexural strength compressive were observed. aim replace much cement...

Asphalt mixtures often fail due to poor interaction between mineral aggregate and bituminous binder. Therefore, many efforts are being made on adhesion improvement the two materials. In this work, paving grade bitumen 50/70 was doped with types of promoters. composed crushed Brant coated by binder were exposed stripping water. Then, they subjected visual digital image analysis aiming quantify residual bitumen-coated areas. Besides, cylindrical samples bonded together a thin film After...