title: Recycling of waste glass as aggregate in cement-based materials

authors: Harrison, Edward

abstract: Glass is a common material made from natural resources such as sand. Although much of the waste glass is recycled to make new glass products, a large proportion is still being sent to landfill. Glass is a useful resource that is non-biodegradable, occupying valuable landfill space. To combat the waste glass that is heading to landfill, alternative recycling forms need to be investigated. The construction industry is one of the largest CO₂ emitters in the world, producing up to 8% of the global CO₂ to produce cement. The use of sand largely depletes natural resources for the creation of mortars or concretes. This review explores the possibilities of incorporating waste glass into cement-based materials. It was found waste glass is unsuitable as a raw material replacement to produce clinker and as a coarse aggregate, due to a liquid state being produced in the kiln and the smooth surface area, respectively. Promising results were found when incorporating fine particles of glass in cement-based materials due to the favourable pozzolanic reaction which benefits the mechanical properties. It was found that 20% of cement can be replaced with waste glass of 20 μm without detrimental effects on the mechanical properties. Replacements higher than 30% can cause negative impacts as insufficient amounts of CaCO₃ remain to react with the silica from the glass, known as the dilution effect. As the fine aggregate replacement for waste glass increases over 20%, the mechanical properties decrease proportionally; however, up to 20% has similar results to traditionally mixes.

text: Recycling of waste glass as aggregate in cement-based materials Glass is a common material made from natural resources such as sand. Although much of the waste glass is recycled to make new glass products, a large proportion is still being sent to landfill. Glass is a useful resource that is non-biodegradable, occupying valuable landfill space. To combat the waste glass that is heading to landfill, alternative recycling forms need to be investigated. The construction industry is one of the largest CO₂ emitters in the world, producing up to 8% of the global CO₂ to produce cement. The use of sand largely depletes natural resources for the creation of mortars or concretes. This review explores the possibilities of incorporating waste glass into cement-based materials. It was found waste glass is unsuitable as a raw material replacement to produce clinker and as a coarse aggregate, due to a liquid state being produced in the kiln and the smooth surface area, respectively. Promising results were found when incorporating fine particles of glass in cement-based materials due to the favourable pozzolanic reaction which benefits the mechanical properties. It was found that 20% of cement can be replaced with waste glass of 20 μm without detrimental effects on the mechanical properties. Replacements higher than 30% can cause negative impacts as insufficient amounts of CaCO₃ remain to react with the silica from the glass, known as the dilution effect. As the fine aggregate replacement for waste glass increases over 20%, the mechanical properties decrease proportionally; however, up to 20% has similar results to traditionally mixes.

year: 2020

title: Whose future? Whose choosing?: Counselling in a context of (im)possible choice.

authors: Kotzé, Elmarie

subjects: school counselling

abstract: Critically reflexive practice is at the heart of counselling, and even more so when clients come face to face with (im)possible choices. As counsellor educators, the authors show counselling practice at the edge of uncertainty. This article features a counselling context in a secondary school. It describes a fictional situation where action is called for in the midst of undecidability, at an impasse in the life of a young woman client. The article explores the aporia that confront the young woman and the counsellor, in the context of education, career, families, cultures and communities. The authors show that these explorations produced transformational questions for their teaching practice as counsellor educators.

text: Whose future? Whose choosing?: Counselling in a context of (im)possible choice. Critically reflexive practice is at the heart of counselling, and even more so when clients come face to face with (im)possible choices. As counsellor educators, the authors show counselling practice at the edge of uncertainty. This article features a counselling context in a secondary school. It describes a fictional situation where action is called for in the midst of undecidability, at an impasse in the life of a young woman client. The article explores the aporia that confront the young woman and the counsellor, in the context of education, career, families, cultures and communities. The authors show that these explorations produced transformational questions for their teaching practice as counsellor educators.

year: 2011

title: Wāhine Māori entrepreneurs and business growth: The power of social and cultural capital

authors: MacDonald, Tui

subjects: Māori enterprise

abstract: This paper examines how social and cultural capital support wāhine Māori entrepreneurs as founders to grow their businesses. The findings are based on the first of three rounds of interviews with 10 wāhine Māori entrepreneurs in Aotearoa New Zealand who have or are undergoing business growth. The results extend on previous Indigenous entrepreneurship research 
showing the benefits of social and cultural capital. This research highlights how wāhine Māori entrepreneurs can pursue business growth while maintaining their community and cultural identity. 
This topic has been selected as part of a broader doctoral study examining wāhine Māori entrepreneurs 
and business growth, which focuses on the cultural, social, and economic enablers and challenges.

text: Wāhine Māori entrepreneurs and business growth: The power of social and cultural capital This paper examines how social and cultural capital support wāhine Māori entrepreneurs as founders to grow their businesses. The findings are based on the first of three rounds of interviews with 10 wāhine Māori entrepreneurs in Aotearoa New Zealand who have or are undergoing business growth. The results extend on previous Indigenous entrepreneurship research 
showing the benefits of social and cultural capital. This research highlights how wāhine Māori entrepreneurs can pursue business growth while maintaining their community and cultural identity. 
This topic has been selected as part of a broader doctoral study examining wāhine Māori entrepreneurs 
and business growth, which focuses on the cultural, social, and economic enablers and challenges.

year: 2024