Includes bibliographical references (leaves 96-100). / Concern for environmental degradation has been a motivating factor in the efforts to reuse or recycle construction and demolition waste. The intention is not only to reduce environmental desecration, but also to recycle the construction and demolition waste into potential building materials to be reused elsewhere. This study investigated the supply and demand of recycled construction materials in the Western Cape, and aimed to determine the perception held by important stakeholders about these materials. A qualitative analysis of the case study results revealed that poor waste management plans implemented on construction and demolition sites have affected the quality, supply and price of recycled materials. In addition to this it was also revealed that the negative perceptions regarding recycled materials were the major barriers to creating an established secondary market. Inadequate knowledge and experience were major contributors to resistance to change of perceptions. A case study was conducted on Malans Quarries Recyclers in order to determine the supply of raw materials (construction and demolition waste) reaching the recycling plant; the supply of recycled materials to the end user (consumer); and the recycling process that takes place. A sample of fifteen respondents from a variety of large, medium and small construction contractors, as well as consultants and civil engineering companies, completed a questionnaire to determine the demand for and perceptions about these materials. The qualitative analysis of the results of the questionnaires showed that the majority of respondents still preferred to use primary materials over recycled materials. However, it appears that the gap between respondents who prefer to use primary materials, and those who utilize recycled materials, has narrowed in comparison to results obtained in previous studies. It seems that there may be more usage of recycled materials in the future. The results also revealed that tax cuts, could be a good economic incentive to encourage the use of recycled material. The questionnaire results also revealed that the majority of the respondents believed that landfill taxes where not effective in discouraging the illegal dumping of waste, and that the lack advertisements, and difficulties in obtaining recycled materials played a crucial role in the under-use of recycled materials.

Long term durability is a major concern for wide-scale use of recycled aggregate materials in civil engineering construction. The purpose of this study is to provide an insight into the damaging effects of combined wet-dry cycles and repeated mechanical loading in a recycled aggregate concrete (RAC) base course material made from recycled crushed concrete aggregate and cement. A coordinated experimental program followed by a mechanistic pavement modeling and life cycle analysis was conducted as part of this research study. This laboratory investigation was divided into three phases each consisting of both wet-dry exposed specimens (WD), and control or non wet-dry exposed specimens (NWD). Phase I experiments involved monotonic loading tests under compression and flexure to evaluate the strength properties. Phase II involved testing a total of 108 cylindrical specimens in cyclic compressive loading at three different stress ratios. After each regime of cyclic loading, residual compressive strengths were determined. In addition, the load-deformation hysteresis loops and the accumulated plastic deformation were continuously monitored through all loading cycles. Phase III included a flexural fatigue test program on 39 beam specimens, and fracture testing program on 6 notched beam specimens, each one having 19-mm initial notch. Traditional SR-N curves, relating the Stress Ratio (SR) with the number of cycles to failure (N or Nf), were developed. Fatigue crack growth rate and changes in Stress Intensity Factors were obtained to determine Paris Law constants and fracture toughness. A mechanistic analysis of a typical highway pavement incorporating RAC base was performed with KENPAVE program, followed by a Life Cycle Analysis (LCA) using the GaBi software. It was found that the specimens subjected to wet-dry cycles suffered significantly higher damage expressed in terms of accumulated plastic deformation, and loss of residual compressive strength, modulus, fatigue endurance limit, and design life, compared to specimens not exposed to wet-dry cycles. Although such degradation in material properties are important considerations in pavement design, a concurrent Life Cycle Analysis demonstrated that recycled aggregate concrete base course still holds promise as an alternative construction material from environmental stand point. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

A urbanização acelerada e o rápido adensamento das cidades de médio e grande porte são fatores que vêm contribuindo para o aumento da quantidade de Resíduos da Construção Civil (RCC) nas cidades brasileiras. A problemática aumenta não somente pelo fato destes constituírem a maior fração em massa dos resíduos gerados nas cidades, mas também pela imprudência ou desconhecimento dos profissionais responsáveis que acompanham as obras. Como consequência ocorre a disposição inadequada dos RCC em locais clandestinos, terrenos baldios, praças, ruas ou encostas de rios. O descarte irregular destes é uma das principais causas da degradação do meio ambiente, com potencial de afetar a qualidade de vida da população, comprometer os recursos naturais e os ecossistemas. Nesse ínterim, este trabalho tem por objetivo investigar como os resíduos vem sendo gerenciados pelos profissionais que atuam com Arquitetura de Interiores no município de Caxias do Sul. A natureza do projeto de pesquisa classifica-se como exploratória, cujos dados primários são de natureza qualitativa, enquanto uma pesquisa posterior é feita para quantificar os dados iniciais obtidos, ambas as etapas envolvendo a elaboração de questionários. Assim, o processo de levantamento de dados necessários à realização da análise desse trabalho, sustentou-se por meio de uma entrevista de profundidade, seguida de uma pesquisa Survey, construída na forma estruturada e aplicada via computador. Ambas direcionadas à uma amostra de Arquitetos e Urbanistas que atuam no município. Os resultados obtidos da Pesquisa de Profundidade sugerem que os profissionais reconhecem a importância do meio ambiente para o bem-estar da sociedade como um todo, porém desconhecem sobre aspectos ligados à gestão, gerenciamento e atribuições legais relacionadas aos RCC. A análise dos resultados da pesquisa Survey reforça essa informação inicial, mapeando dados que mostram o baixo aproveitamento de resíduos na própria obra, a falta de segregação de resíduos, a prática de aterramento de RCC e a deposição irregular em terrenos baldios. Estes dados são fortes indicadores de que o segmento está operando em inconformidade com a legislação brasileira, carecendo de atenção, fiscalização e ações de educação ambiental. Tais medidas se fazem necessárias para se combater a degradação das áreas urbanas e se obter uma consequente melhoria da qualidade de vida da sociedade. / Submitted by Paula Leal (pffleal@ucs.br) on 2017-12-14T11:01:45Z No. of bitstreams: 1 Dissertação Nadime Rissi.pdf: 7217805 bytes, checksum: 8d21c6a81eac13f14a258211c3eca295 (MD5) / Made available in DSpace on 2017-12-14T11:01:45Z (GMT). No. of bitstreams: 1 Dissertação Nadime Rissi.pdf: 7217805 bytes, checksum: 8d21c6a81eac13f14a258211c3eca295 (MD5) Previous issue date: 2017 / The fast urbanization and intensification of medium and large-size cities have increased the quantity of Construction and Demolition Waste (CDW) in Brazilian cities. The problem is not only because the largest waste fraction of CDW generated by cities, but also by imprudence or lack of knowledge of professionals that monitor construction works. The inappropriate placement of CDW occurs in illegal sites, wastelands, squares, streets or river slopes. The irregular disposal of CDW is one of the main causes of the environment degradation since it has the potential to affect the quality of life of the population, compromising natural resources and ecosystems. This study aims to investigate how wastes are being treated by professionals working with interior design in Caxias do Sul. The nature of the research project is explanatory, whose primary data are qualitative while a later research is done to quantify the initial data, involving the preparation of surveys in both stages. Hence, the data collection process required to perform the analysis started with an in-depth interview following by a survey research, which was structurally developed and applied via computer. Both processes were applied to a sample of architectures and planners from Caxias do Sul. The in-depth interview results suggest that professionals recognize the importance of the environment to the welfare of society, but ignoring aspects of operation, management and legal responsibilities to the CDW. The survey analysis enhances the initial information, mapping data that shows low achievement of wastes in civil constructions, lack of waste segmentation, practice of CDW grounding and irregular disposal of CDW in wastelands. These findings are strong evidences that the segment is not in accordance with the Brazilian law, lacking attention, inspection and environmental education. These actions are needed to tackle the degradation of urban areas and achieve improvements in society’s life quality.

Thesis (MTech (Built Environment))--Peninsula Technikon, 2001 / The construction industry globally, contributes between 18% and 24% of the GDP, and because of its labour intensive characteristics, contributes handsomely to total employment, forming important backward and forward linkages with the rest of the economy. Nevertheless, the extent and sophistication of these linkages crucially depend on the relative development of the construction industry relative to the overall economy. In the developing countries, these linkages are not very strong because of the use of informal materials, which is not commercialised and whose opportunity costs are often zero, and the huge imports of construction materials used in the modem sector of the economy. However, whether in the developed or developing economies, the construction industry is a major contributor to economic growth and development by providing the necessary infrastructure that facilitates production, consumption and recreational activities. In fulfilling these activities, the construction industry generates huge wastes of which only a tiny proportion are recycled and reused. However, in economies and countries where adequate and functional housing is a problem mainly due to lack of affordability, recycling and reuse of construction waste is a necessary prerequisite to enhancing housing affordability in these countries. This is the current situation that South Africa finds itself "''here because of its past history of 'apartheid', economic opportunities and amenities were denied to the blacks. There is nowhere that this deprivation is more pronounced than in the built environment sector where housing shortages and general disamenities prevail. High levels of unemployment further exacerbate the situation, - - which is a consequence of low skills and high illiteracy-rates. Thus, housing demand and supply by this group of the population are most likely, on the evidence available, to fall predominantly within the low-income housing category. Presently, all households falling into this category rely on financial assistance from the government to facilitate low-cost housing consumption because of pervasive poverty, which itself is due to the very high unemployment rate, illiteracy, lack of skills and general deprivation: a legacy of 'apartheid' policies enforced by previous government. The dilemma however is how to meet the huge housing demand within the limited resources available to the government on the one hand, and on the other, to satisfy such demand without compromising the environmental sustainability of the physical environment. Thus, the thesis aims to determine ways in which the construction industry could contribute to the sustainability of the carrying capacity of the biophysical environment and enhance social sustainability by facilitating affordability through the possible reductions to construction costs through recycling and reuse. By means of questionnaires and detailed interviews, underscored by a qualitative research approach, the potential of construction recycling and the possible contributions to environmental sustainability and housing affordability are determined. At completion, it is expected that this work will not only contribute to existing knowledge but would be of significance in terms of policy formulation to construction industry practitioners, central and local government policy makers, and other governmental and non-governmental organisations operating in the area of housing.

A urbanização acelerada e o rápido adensamento das cidades de médio e grande porte são fatores que vêm contribuindo para o aumento da quantidade de Resíduos da Construção Civil (RCC) nas cidades brasileiras. A problemática aumenta não somente pelo fato destes constituírem a maior fração em massa dos resíduos gerados nas cidades, mas também pela imprudência ou desconhecimento dos profissionais responsáveis que acompanham as obras. Como consequência ocorre a disposição inadequada dos RCC em locais clandestinos, terrenos baldios, praças, ruas ou encostas de rios. O descarte irregular destes é uma das principais causas da degradação do meio ambiente, com potencial de afetar a qualidade de vida da população, comprometer os recursos naturais e os ecossistemas. Nesse ínterim, este trabalho tem por objetivo investigar como os resíduos vem sendo gerenciados pelos profissionais que atuam com Arquitetura de Interiores no município de Caxias do Sul. A natureza do projeto de pesquisa classifica-se como exploratória, cujos dados primários são de natureza qualitativa, enquanto uma pesquisa posterior é feita para quantificar os dados iniciais obtidos, ambas as etapas envolvendo a elaboração de questionários. Assim, o processo de levantamento de dados necessários à realização da análise desse trabalho, sustentou-se por meio de uma entrevista de profundidade, seguida de uma pesquisa Survey, construída na forma estruturada e aplicada via computador. Ambas direcionadas à uma amostra de Arquitetos e Urbanistas que atuam no município. Os resultados obtidos da Pesquisa de Profundidade sugerem que os profissionais reconhecem a importância do meio ambiente para o bem-estar da sociedade como um todo, porém desconhecem sobre aspectos ligados à gestão, gerenciamento e atribuições legais relacionadas aos RCC. A análise dos resultados da pesquisa Survey reforça essa informação inicial, mapeando dados que mostram o baixo aproveitamento de resíduos na própria obra, a falta de segregação de resíduos, a prática de aterramento de RCC e a deposição irregular em terrenos baldios. Estes dados são fortes indicadores de que o segmento está operando em inconformidade com a legislação brasileira, carecendo de atenção, fiscalização e ações de educação ambiental. Tais medidas se fazem necessárias para se combater a degradação das áreas urbanas e se obter uma consequente melhoria da qualidade de vida da sociedade. / The fast urbanization and intensification of medium and large-size cities have increased the quantity of Construction and Demolition Waste (CDW) in Brazilian cities. The problem is not only because the largest waste fraction of CDW generated by cities, but also by imprudence or lack of knowledge of professionals that monitor construction works. The inappropriate placement of CDW occurs in illegal sites, wastelands, squares, streets or river slopes. The irregular disposal of CDW is one of the main causes of the environment degradation since it has the potential to affect the quality of life of the population, compromising natural resources and ecosystems. This study aims to investigate how wastes are being treated by professionals working with interior design in Caxias do Sul. The nature of the research project is explanatory, whose primary data are qualitative while a later research is done to quantify the initial data, involving the preparation of surveys in both stages. Hence, the data collection process required to perform the analysis started with an in-depth interview following by a survey research, which was structurally developed and applied via computer. Both processes were applied to a sample of architectures and planners from Caxias do Sul. The in-depth interview results suggest that professionals recognize the importance of the environment to the welfare of society, but ignoring aspects of operation, management and legal responsibilities to the CDW. The survey analysis enhances the initial information, mapping data that shows low achievement of wastes in civil constructions, lack of waste segmentation, practice of CDW grounding and irregular disposal of CDW in wastelands. These findings are strong evidences that the segment is not in accordance with the Brazilian law, lacking attention, inspection and environmental education. These actions are needed to tackle the degradation of urban areas and achieve improvements in society’s life quality.

Using recycled concrete aggregate (RCA) as a replacement for natural aggregate in new concrete is a promising way to increase the overall sustainability of new concrete. This has been hindered, however, by a general perception that RCA is a sub-standard material due to the lack of technical guidance, specifically related to long-term durability, on incorporating RCA into new concrete. The goal of this research project was to determine whether current testing methods could be used to assess the potential alkali-silica reactivity of concrete incorporating RCA. The test methods investigated were ASTM C1260 and ASTM C1567 for assessing natural aggregate susceptibility to alkali-silica reactivity (ASR), and the ability of supplementary cementitious materials (SCMs) to mitigate ASR, respectively. Seven different RCA sources were investigated. It was determined that ASTM C1260 was effective in detecting reactivity but expansion varied based on RCA processing. Depending on the aggregate type and the extent of processing, up to a 100% increase in expansion was observed. Replicate testing was performed at four university laboratories to evaluate repeatability and consistency of results. The authors recommend modification to the mixing and aggregate preparation procedures, when testing the reactivity of RCA using ASTM C 1260. This study also investigated the efficacy of replacing portland cement with supplementary cementitious materials (SCMs), known to mitigate alkali-silica reaction (ASR) in concrete with virgin aggregates, to control ASR in concrete incorporating reactive RCA. The SCMs investigated as part of this study included: fly ash (class F), silica fume, and metakaolin. The results of modified alkali-silica reactivity tests, ASTM C1260 and ASTM C1567 (AMBT), are presented for two different recycled concrete aggregates when using 100% portland cement, binary blends of portland cement and fly ash, and ternary blends of portland cement, fly ash and metakaolin or silica fume. The results indicate that SCMs can effectively mitigate ASR in concrete made with RCA. A 40% replacement of portland cement with class F fly ash was able to reduce expansions to below 0.10% in the AMBT for concrete containing 100% of a highly reactive recycled concrete aggregate. A ternary blend, however, of portland cement with a class F fly ash and metakaolin was most effective for both RCAs tested in this study. Higher levels of mitigation may be required for some RCAs, compared to the level required to mitigate ASR in concrete made with their original natural aggregates, depending on the age and composition of the RCA. / Graduation date: 2012