1,102 research outputs found

    Effects of advera® warm mix additive on the rheological properties of unaged and short term aged asphalt binders

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    The performance of asphalt pavement is mainly governed by the properties of the binder. Many asphalt pavement distress are pronounced to be related to the rheological properties of asphalt binder. The oxidation changes the structure and composition of asphalt binder resulting stiffer and brittle of asphalt. This paper described SuperpaveTM binder that was used to characterize the rheological properties of PG64 asphalt binders blended with various Advera® contents subjected to unaged and short term aged. Rotational viscometer (RV) and Dynamic Shear Rheometer (DSR) were conducted to measure binder properties at higher and intermediate temperature respectively. The results indicated that, the addition of Advera® in the asphalt binder exhibited change in binder rheology which influenced rutting parameteryKeywords: Advera®; Aging; Viscosity; Rotational viscometer; Dynamic shear rheometer

    Physical Characterization of Modified Asphalt Binder with Differing Fly Ash Geopolymer Contents

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    Nowadays, the use of waste material product has gained popularity in the production of asphalt mixes and becomes a cost-effective method of pavement construction that can decrease the consumption of natural resources and to reduce environmental pollution. This research aimed to investigate the possibility of using waste and by-product material namely fly ash geopolymer additive to influence the physical properties of asphalt binder. An experimental matrix of laboratory testing was conducted to study the properties of the 60/70 and 80/100 asphalt binder with modified binder containing 3%, 5%, 7%, 9% and 11% of fly ash geopolymer additive. The physical properties of the binders were determined using the penetration, softening, penetration index, ductility, and rotational viscosity respectively. The results indicated that, the fly ash geopolymer modified binder had improved the physical properties over base binder. The thermal susceptibility also improved by referring to the Penetration Index value. Overall research conclusions are that geopolymer application resulted in a potential enhancement of some of the properties of the asphalt binder and increase the performance of asphalt binder in the pavement application

    Physical Characterization of Modified Asphalt Binder with Differing Fly Ash Geopolymer Contents

    Get PDF
    Nowadays, the use of waste material product has gained popularity in the production of asphalt mixes and becomes a cost-effective method of pavement construction that can decrease the consumption of natural resources and to reduce environmental pollution. This research aimed to investigate the possibility of using waste and by-product material namely fly ash geopolymer additive to influence the physical properties of asphalt binder. An experimental matrix of laboratory testing was conducted to study the properties of the 60/70 and 80/100 asphalt binder with modified binder containing 3%, 5%, 7%, 9% and 11% of fly ash geopolymer additive. The physical properties of the binders were determined using the penetration, softening, penetration index, ductility, and rotational viscosity respectively. The results indicated that, the fly ash geopolymer modified binder had improved the physical properties over base binder. The thermal susceptibility also improved by referring to the Penetration Index value. Overall research conclusions are that geopolymer application resulted in a potential enhancement of some of the properties of the asphalt binder and increase the performance of asphalt binder in the pavement application

    Dynamic Creep Performance of Hot Mix Asphalt Mixture Incorporating Fibre

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    Permanent deformation is one of the distress that develops gradually as the number of load applications increases and appears as longitudinal depressions in the wheel paths and small upheavals to the sides. For this reason, numerous studies conducted on modification asphalt binder or mixture by various fibre. This paper presents the evaluation of creep modulus and permanent deformation of modified asphalt mixture with fibres. In order to envisage the modified asphalt mixture, Forta-fi, Kenaf and PET was blended to estimate the creep properties and rut depth value at different loading pattern. Superpave mix design method was employed with NMAS 12.5mm to obtain the optimum bitumen content established at 4% air void. In the respect, bitumen 60/70 penetration grade with 0.5% of Forta-Fi, 0.1% Kenaf fibre and 0.5% PET by weight of asphalt mixture were prepared. Dynamic Creep Test was performed in accordance to the EN 12697-25:2005 guidelines using the Universal Testing Machine (UTM). As the result, the minimum value of permanent deformation was found at 0.5% of PET. Based on these studies, adding a minimum percent of PET in the asphalt mixture shows a better resistance to rutting deformation and enable a better understanding of the properties in modified asphalt mixtures

    Dynamic Creep Performance of Hot Mix Asphalt Mixture Incorporating Fibre

    Get PDF
    Permanent deformation is one of the distress that develops gradually as the number of load applications increases and appears as longitudinal depressions in the wheel paths and small upheavals to the sides. For this reason, numerous studies conducted on modification asphalt binder or mixture by various fibre. This paper presents the evaluation of creep modulus and permanent deformation of modified asphalt mixture with fibres. In order to envisage the modified asphalt mixture, Forta-fi, Kenaf and PET was blended to estimate the creep properties and rut depth value at different loading pattern. Superpave mix design method was employed with NMAS 12.5mm to obtain the optimum bitumen content established at 4% air void. In the respect, bitumen 60/70 penetration grade with 0.5% of Forta-Fi, 0.1% Kenaf fibre and 0.5% PET by weight of asphalt mixture were prepared. Dynamic Creep Test was performed in accordance to the EN 12697-25:2005 guidelines using the Universal Testing Machine (UTM). As the result, the minimum value of permanent deformation was found at 0.5% of PET. Based on these studies, adding a minimum percent of PET in the asphalt mixture shows a better resistance to rutting deformation and enable a better understanding of the properties in modified asphalt mixtures

    Development of the Guernsey Community Participation and Leisure Assessment – Revised (GCPLA-R).

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    A sufficiently psychometrically robust measure of community and leisure participation of adults with intellectual disabilities was not in existence, despite research identifying this as an important outcome and a key contributor to quality of life. The current study aimed to update the Guernsey Community Participation and Leisure Assessment (GCPLA). Adults with intellectual disabilities, carers and experts were consulted in creating a revised pool of 46 items. These were then tested and data from 326 adults with intellectual disabilities were analysed for their component structure and psychometric properties. Principal Component analysis discovered a stable set of components describing seven different clusters. This revised measure (the GCPLA-R) was demonstrated to have satisfactory reliability, and scores were related to challenging behaviour and adaptive behaviour in theoretically consistent ways and were correlated with scores on comparable measures

    Development of an MFL Coil Sensor for Testing Pipes in Extreme Temperature Conditions

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    This paper aims to design a coil sensor for corrosion monitoring of industrial pipes that could detect variations in thickness using the MFL (Magnetic Flux Leakage) technique. An MFL coil sensor is designed and tested with pipe sample thicknesses of 2, 4, 6, and 8 mm based on the magnetic field effect of ferrite cores. Moreover, a measurement setup for analysing pipe samples up to a temperature of 200° Celsius is suggested. Experimental results reveal that the MFL coil sensor can fulfil the requirements for MFL testing of pipes in high temperature conditions, and that the precision of MFL monitoring of pipes to detect corrosion at high temperatures can be improved significantly

    Evaluation of Nigerian public housing performance using occupants’ experience and satisfaction

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    There is misconception of occupants’ satisfaction and experience in building performance evaluation due to inadequacy of in-depth studies on each, which resulted to insufficiency of facts about their structure, determinant variables, effects of socioeconomic attributes and conditions under which they are connected. Objective of the study were to identify the building performance levels and differences between occupants’ satisfaction and experience, effects of socioeconomic attributes on them and propose a framework to evaluate public housing performance using occupants’ satisfaction and experience. Building Use Studies (BUS) Methodology, UK questionnaire was adapted and used on a license agreement. Systematic random sampling was used to collect data from 300 occupants of four (4) public housing estates in Gombe metropolis Nigeria. Two independent factors of tangible and intangible building features were conceptualised. Exploratory factor analysis (EFA) was used in the pilot survey to identify the factorability of the variables. The Confirmatory factor analysis (CFA) in AMOS software was used to validate the constructs and develop two structural equation models (SEM) based on occupants satisfaction and experience. The models were subjected to multi CFA moderation method to determine the effects of socioeconomic attributes of the occupants. The results indicated differences in performance of features based on occupants’ satisfaction and experience. The SEM moderation results showed that education and income moderates occupants’ satisfaction, while they does not moderates occupants’ experience. Therefore, the study concluded with emphasis on the importance of occupants experience as an objective measure of building performance against occupants’ satisfaction’s subjectivity. Based on that, a framework to evaluate public housing performance using occupants’ satisfaction and experience was proposed
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