The Experts below are selected from a list of 4836 Experts worldwide ranked by ideXlab platform
Erik Schlangen - One of the best experts on this subject based on the ideXlab platform.
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The reinforcement and healing of asphalt mastic Mixtures by rejuvenator encapsulation in alginate compartmented fibres
Smart Materials and Structures, 2016Co-Authors: Amir Tabakovic, W. Post, Oğuzhan Çopuroğlu, S J Garcia, Domingo Cantero, Erik SchlangenAbstract:? 2016 IOP Publishing Ltd.This paper explores the potential use of compartmented alginate fibres as a new method of incorporating rejuvenators into asphalt pavement Mixtures. The compartmented fibres are employed to locally distribute the rejuvenator and to overcome the problems associated with spherical capsules and hollow fibres. The work presents proof of concept of the encapsulation process which involved embedding the fibres into the asphalt mastic Mixture and the survival rate of fibres in the asphalt Mixture. To prove the effectiveness of the alginate as a rejuvenator encapsulating material and to demonstrate its ability survive asphalt production process, the fibres containing the rejuvenator were prepared and subjected to thermogravimetric analysis and uniaxial tensile test. The test results demonstrated that fibres have suitable thermal and mechanical strength to survive the asphalt Mixing and compaction process. The CT scan of an asphalt Mortar Mix containing fibres demonstrated that fibres are present in the Mix in their full length, undamaged, providing confirmation that the fibres survived the asphalt production process. In order to investigate the fibres physiological properties and ability to release the rejuvenator into cracks in the asphalt mastic, the environmental scanning electron microscope and optical microscope analysis were employed. To prove its success as an asphalt healing system, compartmented alginate fibres containing rejuvenator were embedded in asphalt mastic Mix. The three point bend tests were performed on the asphalt mastic test samples and the degree to which the samples began to self-heal in response was measured and quantified. The research findings indicate that alginate fibres present a promising new approach for the development of self-healing asphalt pavement systems.
Zbysek Pavlik - One of the best experts on this subject based on the ideXlab platform.
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diatomite powder as pozzolana active mineral adMixture in Mortar Mix composition
SPECIAL CONCRETE AND COMPOSITES 2019: 16th International Conference, 2020Co-Authors: Simon Marusiak, Milena Pavlikova, Zbysek PavlikAbstract:The aim of the study was investigate the possible use of diatomite powder as a partial replacement of Portland cement in the production of cement Mortar. Diatomite was used as 10% and 20% replacement by weight of cement while sand quantity and water dosage were kept constant. The particle size distribution of diatomite was researched on a laser diffraction principle, whereas its pozzolana activity was also studied. For the materials with diatomite as well as for control Mortar, basic structural properties, compressive and flexural strengths, freeze–thaw resistance, dynamic modulus of elasticity, sorption and desorption isotherms were measured. The diatomite use led to the decrease in porosity, and thus to the increase in mechanical resistance of the tested Mortars. On the other hand, the frost resistance of Mortars with incorporated diatomite powder was lower compared to control PC-based Mortar. The water vapor storage capacity of diatomite enriched Mortars slightly increase compared to the control Mix, but the maximum moisture storage remained low in general.
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ternary blended binder for production of a novel type of lightweight repair Mortar
Materials, 2019Co-Authors: Milena Pavlikova, Jaroslav Pokorný, Martina Záleská, Lucie Zemanova, Ondřej Jankovský, Michal Lojka, Zbysek PavlikAbstract:The goal of the paper was development and testing of a novel type of ternary blended binder based on lime hydrate, metakaolin, and biomass ash that was studied as a binding material for production of lightweight Mortar for renovation purposes. The biomass ash used as one of binder components was coming from wood chips ash combustion in a biomass heating plant. The raw ash was mechanically activated by grinding. In Mortar composition, wood chips ash and metakaolin were used as partial substitutes of lime hydrate. Silica sand of particle size fraction 0⁻2 mm was Mixed from three normalized sand fractions. For the evaluation of the effect of biomass ash and metakaolin incorporation in Mortar Mix on material properties, reference lime Mortar was tested as well. Among the basic physical characterization of biomass ash, metakaolin and lime hydrate, specific density, specific surface, and particle size distribution were assessed. Their chemical composition was measured by X-Ray fluorescence analysis (XRF), morphology was examined using scanning electron microscopy (SEM), elements mapping was performed using energy dispersive spectroscopy (EDS) analyser, and mineralogical composition was tested using X-Ray diffraction (XRD). For the developed Mortars, set of structural, mechanical, hygric, and thermal properties was assessed. The Mortars with ternary blended binder exhibited improved mechanical resistance, lower thermal conductivity, and increased water vapor permeability compared to the reference lime Mortar. Based on good functional performance of the produced Mortar, the tested biomass ash could potentially represent a novel sustainable alternative to other pozzolans commonly used in construction industry. Moreover, reuse of biomass ash in production of building materials is highly beneficial both from the environmental and economic reasons especially taking into account circular economy principles. The ternary blended binder examined in this paper can find use in both rendering and walling repair Mortars meeting the requirements of culture heritage authorities and technical standards.
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valorization of wood chips ash as an eco friendly mineral adMixture in Mortar Mix design
Waste Management, 2018Co-Authors: Milena Pavlikova, Jaroslav Pokorný, Martina Záleská, Lucie Zemanova, Ondřej Jankovský, Michal Lojka, David Sedmidubský, Zbysek PavlikAbstract:Wood chips ash coming from biomass heating plant is studied as an eco-friendly mineral adMixture in Mortar Mix design. The raw material was mechanically activated by milling in a vibratory disc mill to a degree of fineness comparable to cement. For the Mortars with ash dosage, basic physical, mechanical, hygric, and thermal properties is accessed. The Mortars with partial Portland cement replacement with wood chips ash exhibited good functional properties for all studied ash dosages. With increasing amount of the ash used, the average pore diameter decreased due to the partial filler effect of WCHA in Mortar Mix. The strength activity index was very high for all studied Mortars and gave evidence of the wood chips ash pozzolanity. The pozzolan effectiveness coefficient varied from 1.52 to 0.59, which proved the pozzolanity of the studied ash and synergic effects in the Portland cement-ash-water system. The results of leaching tests showed, the chlorides contained in ash were safely immobilized in the silicate matrix. The environmental evaluation revealed decrease in both carbon dioxide production and energy consumption by the use of wood chips ash in Mortar Mix. For the Mortar with 20% substitution of Portland cement with wood chips ash, it represents 15% of CO2 and 16% of energy, as compared with the reference Mortar Mix. As the developed Mortars possess good functional and environmental parameters the analyzed wood chips ash can be considered as an eco-efficient low-cost alternative to other pozzolans for production of blended binders.
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fine ceramic powder supplementary cementitious material for Mortar Mix design
Key Engineering Materials, 2016Co-Authors: Tereza Kulovaná, Jaroslav Pokorný, Martina Záleská, Milena Pavlikova, Zbysek PavlikAbstract:Waste ceramic powder originating from the contemporary hollow bricks production is studied as a supplementary cementitious material in Mortar composition. For the ceramic powder and cement, the measurement of chemical composition is done using XRF analysis. XRD device is used for the amorphous phase content measurement. The particle size distribution of ceramics and cement is accessed on a laser diffraction principle. Pozzolanic activity of ceramic powder was determined by the modified Chapelle test. The blended binder containing ceramic powder in an amount of 8, 16, and 24% of mass of cement is used for the preparation of Mortars which are then characterized using the measurement of basic physical properties and mechanical properties. Among the basic physical properties, bulk density, matrix density and total open porosity are measured. The mechanical resistivity of Mortars with blended binder is accessed by the compressive strength, flexural strength, and dynamic Young’s modulus measurement. Additionally, pore-size distribution of the developed Mortars is analyzed using mercury intrusion porosimetry. Experimental data shows that an application of 24% waste ceramics in the blended binder provides sufficient mechanical resistivity of the Mortar.
Lucie Fusade - One of the best experts on this subject based on the ideXlab platform.
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The effect of wood ash on the properties and durability of lime Mortar for repointing damp historic buildings
Construction and Building Materials, 2019Co-Authors: Lucie Fusade, Heather Viles, Chris Wood, Colin BurnsAbstract:Abstract Historical evidence shows that wood ash has been used in lime Mortar to help absorb moisture from masonry walls. In this study, an experimental programme was designed to assess the impact that varying the content of wood ash has on a range of properties of lime Mortar and to draw conclusions about the reasons for these impacts. Biomass wood ash was added to Mortars made with natural hydraulic lime (NHL) and air lime (AL) as an aggregate replacement at different concentrations: 0% (control Mix), 10%, 20%, 30%, 40%, 70% and 100%. Compressive strength, strength activity index, open and total porosity, pore size distribution, water absorption by capillarity, desorption, water vapour permeability, and freeze-thaw durability were assessed after 90 days. The results indicate that fine particles of wood ash induce a higher proportion of pores in the capillary range and a higher open porosity. The tight structure of lime and wood ash increases the compressive strength. The fine particles given from the wood ash could also be responsible for the potential pozzolanic activity. Furthermore, by being hygroscopic, wood ash gives lime Mortars a capacity to hold more water, resulting in a delayed capillary absorption, while retaining good desorption. The research findings imply that, used at its best potential in medium amounts (20–40%), adding wood ash in lime Mortar gives a potentially good Mortar Mix for repointing masonry joints, especially in damp environments. However, in high amounts (70–100%) some negative effects are seen, such as high drying shrinkage.
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Drying response of lime-Mortar joints in granite masonry after an intense rainfall and after repointing
Heritage Science, 2019Co-Authors: Lucie Fusade, Chris Wood, Meriel O’dowd, Heather VilesAbstract:When rain impacts a building façade, it is essential that once it has entered, it leaves by evaporation to help the building dry out. Accumulation of moisture can lead to internal dampness, mould and decay of valuable masonry by salt weathering. In a solid masonry wall where the stone is of low permeability, such as granite which is found in many historic buildings, rain water mainly enters and leaves through Mortar joints. If granite stone masonry needs repointing, the repair Mortar must allow the overall masonry to dry out. This study evaluates the drying response of various lime-based repointing Mortars Mixes in small granite stone masonry constructions (test walls) subjected to a simulated intense short rain event and then left to dry. It determines the moisture movement through Mortar joints, the influence of materials, joint types and workmanship, and whether repointing could mitigate moisture ingress and help masonry dry out. This study developed a novel experimental protocol which allowed comparison of the drying response of different Mortar types in a low-porosity stone masonry system and the effect of repointing. Five test walls were built of Cornish granite with five different lime Mortar Mixes combining NHL 3.5 (St Astier) gauged with non-hydraulic quicklime (Shap), quartz and calcitic sand and biomass wood ash as additives. Simulated intense rain was sprayed on each wall over a 3.25 h spell. Drying was monitored over a week with a microwave moisture device (MOIST350B). Measurements were done at surface and depth on both Mortar joints and granite units. Each wall was then repointed with the same Mortar Mix initially used when built and the same rain simulation was performed to evaluate differences repointing could make to the moisture dynamics. The importance of Mortar in dealing with moisture movements in the test wall and absorbing moisture from the stones was demonstrated. Gauged binder and wood ash additives decreased the capillary absorption capacity of Mortars while retaining a good drying rate. This study has also showed that after repointing water did not penetrate as deep under the same conditions. Therefore repointing reduces the threat of water ingress and shows that it could be a suitable conservation intervention to mitigate water ingress and accelerate drying.
Colin Burns - One of the best experts on this subject based on the ideXlab platform.
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The effect of wood ash on the properties and durability of lime Mortar for repointing damp historic buildings
Construction and Building Materials, 2019Co-Authors: Lucie Fusade, Heather Viles, Chris Wood, Colin BurnsAbstract:Abstract Historical evidence shows that wood ash has been used in lime Mortar to help absorb moisture from masonry walls. In this study, an experimental programme was designed to assess the impact that varying the content of wood ash has on a range of properties of lime Mortar and to draw conclusions about the reasons for these impacts. Biomass wood ash was added to Mortars made with natural hydraulic lime (NHL) and air lime (AL) as an aggregate replacement at different concentrations: 0% (control Mix), 10%, 20%, 30%, 40%, 70% and 100%. Compressive strength, strength activity index, open and total porosity, pore size distribution, water absorption by capillarity, desorption, water vapour permeability, and freeze-thaw durability were assessed after 90 days. The results indicate that fine particles of wood ash induce a higher proportion of pores in the capillary range and a higher open porosity. The tight structure of lime and wood ash increases the compressive strength. The fine particles given from the wood ash could also be responsible for the potential pozzolanic activity. Furthermore, by being hygroscopic, wood ash gives lime Mortars a capacity to hold more water, resulting in a delayed capillary absorption, while retaining good desorption. The research findings imply that, used at its best potential in medium amounts (20–40%), adding wood ash in lime Mortar gives a potentially good Mortar Mix for repointing masonry joints, especially in damp environments. However, in high amounts (70–100%) some negative effects are seen, such as high drying shrinkage.
Amir Tabakovic - One of the best experts on this subject based on the ideXlab platform.
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The reinforcement and healing of asphalt mastic Mixtures by rejuvenator encapsulation in alginate compartmented fibres
Smart Materials and Structures, 2016Co-Authors: Amir Tabakovic, W. Post, Oğuzhan Çopuroğlu, S J Garcia, Domingo Cantero, Erik SchlangenAbstract:? 2016 IOP Publishing Ltd.This paper explores the potential use of compartmented alginate fibres as a new method of incorporating rejuvenators into asphalt pavement Mixtures. The compartmented fibres are employed to locally distribute the rejuvenator and to overcome the problems associated with spherical capsules and hollow fibres. The work presents proof of concept of the encapsulation process which involved embedding the fibres into the asphalt mastic Mixture and the survival rate of fibres in the asphalt Mixture. To prove the effectiveness of the alginate as a rejuvenator encapsulating material and to demonstrate its ability survive asphalt production process, the fibres containing the rejuvenator were prepared and subjected to thermogravimetric analysis and uniaxial tensile test. The test results demonstrated that fibres have suitable thermal and mechanical strength to survive the asphalt Mixing and compaction process. The CT scan of an asphalt Mortar Mix containing fibres demonstrated that fibres are present in the Mix in their full length, undamaged, providing confirmation that the fibres survived the asphalt production process. In order to investigate the fibres physiological properties and ability to release the rejuvenator into cracks in the asphalt mastic, the environmental scanning electron microscope and optical microscope analysis were employed. To prove its success as an asphalt healing system, compartmented alginate fibres containing rejuvenator were embedded in asphalt mastic Mix. The three point bend tests were performed on the asphalt mastic test samples and the degree to which the samples began to self-heal in response was measured and quantified. The research findings indicate that alginate fibres present a promising new approach for the development of self-healing asphalt pavement systems.