title: Feasibility Study of Reclaimed Asphalt Pavements (RAP) as Recycled Aggregates Used in Rigid Pavement Construction.

authors: Rout, M. K. Diptikanta

subjects: RAP

abstract: Reclaimed Asphalt Pavement (RAP) as recycled aggregates is a relatively new construction process of rigid pavements due to the scarcity and degradation of natural aggregates. This study aims at the sequential characterization of RAP aggregate to obtain optimized proportions for strength. For this purpose, RAP aggregates were used for the replacement of natural aggregates (NA) in the concrete mix which was achieved by varying from 0-100%. Furthermore, zirconia silica fume (ZSF) was used as a partial replacement of the cement in the concrete mix, replacing Ordinary Portland Cement (OPC). Experimental studies have shown that the incorporation of washed RAP (WRAP) slightly reduces the compressive strength of concrete by 2.7-37.35% as compared to the reference control concrete mix. Although the 7-days, 28-days and 56-day compressive strength of WRAP recycled aggregate-based concrete is slightly better than the 7-days, 28-days and 56-day compressive strength of dirty RAP (DRAP) recycled aggregate-based concrete. A similar trend was observed in the flexural strength and split tensile strength of WRAP recycled aggregate-based. Overall, the results show that 40% WRAP recycled aggregates with 10% ZSF as a replacement for cement outperform DRAP aggregates in concrete mixes. According to the ANOVA results, the combination of ZSF and WRAP aggregates met the cement concrete pavement strength standard, thereby contributing to sustainable development. Reclaimed Asphalt Concrete Pavements (RACP) are now seen as a potential and long-term answer to the present environmental and economic crisis.

text: Feasibility Study of Reclaimed Asphalt Pavements (RAP) as Recycled Aggregates Used in Rigid Pavement Construction. Reclaimed Asphalt Pavement (RAP) as recycled aggregates is a relatively new construction process of rigid pavements due to the scarcity and degradation of natural aggregates. This study aims at the sequential characterization of RAP aggregate to obtain optimized proportions for strength. For this purpose, RAP aggregates were used for the replacement of natural aggregates (NA) in the concrete mix which was achieved by varying from 0-100%. Furthermore, zirconia silica fume (ZSF) was used as a partial replacement of the cement in the concrete mix, replacing Ordinary Portland Cement (OPC). Experimental studies have shown that the incorporation of washed RAP (WRAP) slightly reduces the compressive strength of concrete by 2.7-37.35% as compared to the reference control concrete mix. Although the 7-days, 28-days and 56-day compressive strength of WRAP recycled aggregate-based concrete is slightly better than the 7-days, 28-days and 56-day compressive strength of dirty RAP (DRAP) recycled aggregate-based concrete. A similar trend was observed in the flexural strength and split tensile strength of WRAP recycled aggregate-based. Overall, the results show that 40% WRAP recycled aggregates with 10% ZSF as a replacement for cement outperform DRAP aggregates in concrete mixes. According to the ANOVA results, the combination of ZSF and WRAP aggregates met the cement concrete pavement strength standard, thereby contributing to sustainable development. Reclaimed Asphalt Concrete Pavements (RACP) are now seen as a potential and long-term answer to the present environmental and economic crisis.

year: 2023-02-10

title: Sociocultural theory and the teaching of process writing: The scaffolding of learning in a university context

authors: Barnard, Roger

subjects: education

abstract: This paper considers how independent and interdependent learning can be fostered through a process approach to the teaching of writing. It does so by presenting the theoretical rational which underlies a university academic skills programme. Drawing on reports of this programme which have been published elsewhere (e.g., Brine & Campbell, 2002), it is a case study illustrating how scaffolding can be effected by teachers and students. The paper begins by briefly reviewing three central concepts of sociocultural theory: the zone of proximal development, scaffolding, and appropriation. Attention is then turned to a consideration of writing as a collaborative process rather than as a product of solitary endeavour. Details are provided about a university course which applies sociocultural concepts to the adoption of a process approach to EAP writing. Attention is then given to the ways by which six principles of scaffolding (Van Lier, 1996) are applied throughout the course. Firstly, various forms of tutor scaffolding are outlined, and then a short sample of transcript data illustrates how students on this course can work collaboratively to co-construct texts and scaffold each other's learning. The paper concludes with a brief discussion of the broader pedagogical implications of sociocultural theory to the teaching of writing.

text: Sociocultural theory and the teaching of process writing: The scaffolding of learning in a university context This paper considers how independent and interdependent learning can be fostered through a process approach to the teaching of writing. It does so by presenting the theoretical rational which underlies a university academic skills programme. Drawing on reports of this programme which have been published elsewhere (e.g., Brine & Campbell, 2002), it is a case study illustrating how scaffolding can be effected by teachers and students. The paper begins by briefly reviewing three central concepts of sociocultural theory: the zone of proximal development, scaffolding, and appropriation. Attention is then turned to a consideration of writing as a collaborative process rather than as a product of solitary endeavour. Details are provided about a university course which applies sociocultural concepts to the adoption of a process approach to EAP writing. Attention is then given to the ways by which six principles of scaffolding (Van Lier, 1996) are applied throughout the course. Firstly, various forms of tutor scaffolding are outlined, and then a short sample of transcript data illustrates how students on this course can work collaboratively to co-construct texts and scaffold each other's learning. The paper concludes with a brief discussion of the broader pedagogical implications of sociocultural theory to the teaching of writing.

year: 2005-01-01

title: Te kōrero kāpehu whenua planning for Te Whakatōhea kai (food) security

authors: Davis, Shannon

abstract: Oral presentation from the Adaptation Futures Conference held at Te Pae Christchurch Convention Centre, Ōtautahi Christchurch.

text: Te kōrero kāpehu whenua planning for Te Whakatōhea kai (food) security Oral presentation from the Adaptation Futures Conference held at Te Pae Christchurch Convention Centre, Ōtautahi Christchurch.

year: 2025