A reciclagem profunda com adição de cimento Portland é uma técnica de recuperação estrutural e funcional de pavimentos empregada há muitos anos no país, devido a vantagens técnicas, econômicas e ambientais. Contudo, a difusão mais ampla da técnica esbarra na carência de normas e procedimentos nacionais, o que resulta na adoção de variados critérios nos projetos que incluem reciclagem com cimento, às vezes, comprometendo sua eficácia. A pesquisa relatada nesta dissertação teve por objetivo principal estabelecer as bases para a proposição de um método de dosagem para reciclagem de pavimentos com adição de cimento, considerando-se como referência o método de dosagem de materiais estabilizados com cimento da Austroads (2002). Para verificar a validade deste método para materiais de pavimentos brasileiros, desenvolveu-se um programa experimental no qual foram avaliadas propriedades mecânicas (resistência, rigidez e erodibilidade) e volumétricas (retração, absorção, expansão e ascensão capilar) de misturas constituídas por fresado asfáltico, brita graduada e cimento, variando-se a porcentagem de fresado (20% e 50%), o teor de cimento (2%, 4% e 6%), a energia de compactação (Intermediária e Modificada) e o tempo de cura dos corpos de prova (3, 7 e 14 dias). Os resultados dos ensaios mostraram que todas as variáveis analisadas afetam significativamente a resistência à compressão simples, a resistência à tração por compressão diametral e o módulo de resiliência das misturas, enquanto que a retração, a erodibilidade, a absorção, a expansão e a ascensão capilar são afetadas por algumas das variáveis independentes. Dentre outras conclusões, destaca-se que são obtidos elevados valores de resistência à compressão simples (1,61 MPa a 6,08 MPa), resistência à tração por compressão diametral (0,29 MPa a 1,00 MPa) e de módulo de resiliência (10390 MPa a 25719 MPa) com teores baixo (2%) e médio (4%) de cimento, sendo desnecessário e arriscado, pela elevada retração associada, o emprego de teor mais elevado (6%). Ainda, observou-se que o aumento da energia de compactação permite compensar a utilização de teores mais baixos de cimento no que se refere às resistências (à compressão, à tração e à erosão) e módulos obtidos. Globalmente, conclui-se que o método de dosagem de materiais estabilizados com cimento da Austroads (2002) pode ser usado como modelo para o desenvolvimento de um método de dosagem para reciclagem de pavimentos com adição de cimento, sendo necessárias pequenas complementações ou adaptações. O método de dosagem sugerido nesta Dissertação é, ao mesmo tempo, simples o suficiente para ser empregado em laboratórios de canteiros de obra e amplo o bastante para identificar as propriedades mecânicas e volumétricas que devem ser avaliadas ao elaborar-se um projeto de mistura reciclada com cimento. / Full-depth reclamation (FDR) with Portland cement is a technique used for structural and functional rehabilitation of pavements and has been used in Brazil for many years, especially because its technical, economical and environmental advantages. However, a larger diffusion of the technique has been inhibited by the lack of national standards and procedures, resulting in the adoption of different design criteria, which sometimes leads to a low efficiency of the FDR with cement. This research was carried out with the objective of setting the basis for a mix design method for FDR with cement, considering the Austroads (2002) mix design method for stabilized pavement materials as a model. In order to verify the applicability of the Austroads method to Brazilian pavement materials, an experimental program was carried out testing mechanical (strength, stiffness and durability) and volumetric (drying shrinkage, absorption, swell and capillary rise) properties of mixtures made of reclaimed asphalt pavement (RAP), graded crushed stone and cement. Specimens with different RAP contents (20% and 50%), cement contents (2%, 4% and 6%), compacted with two different efforts (Brazilian Intermediate and Modified) were cured for 3, 7 and 14 days. Test results showed that all the studied variables affect the unconfined compressive strength, indirect tensile strength and resilient modulus of the mixtures, while drying shrinkage, erodibility, absorption, swell and capillary rise are affected by some of the independent variables. Among other conclusions, it is pointed out that high values of unconfined compressive strength (1,61 MPa to 6,08 MPa), indirect tensile strength (0,29 MPa to 1,00 MPa) and resilient modulus (10390 MPa to 25719 MPa) may be achieved with low (2%) and intermediary (4%) cement contents, thus making the use of higher (6%) cement content unnecessary and unsafe, due to the higher costs and to the drying shrinkage associated. It was also observed that increases in the compaction effort may compensate the use of lower cement contents as regards to strengths and moduli obtained. Generally, can be concluded that the Austroads (2002) mix design method for stabilized pavement materials may be used as a model for the development of a mix design method for FDR with cement, being necessary only a few additions or adaptations. The suggested method is, simultaneously, simple enough to be used in field laboratories and comprehensive enough for including the mechanical and volumetric properties that must be evaluated when designing a mix for FDR with cement.

abstract: Crumb rubber use in asphalt mixtures using wet process technology has been in practice for years in the United States with good performance history; however, it has some drawbacks that include the need for special blending equipment, high rubber-binder temperatures, and longer waiting time at mixing plants. Pre-treated crumb rubber technologies are emerging as a new method to produce asphalt rubber mixtures in the field. A new crumb rubber modifier known as Reacted and Activated Rubber (RAR) is one such technology. RAR (industrially known as “RARX”) acts like an Enhanced Elastomeric Asphalt Extender to improve the engineering properties of the binder and mixtures. It is intended to be used in a dry mixing process with the purpose of simplifying mixing at the asphalt plant. The objective of this research study was first to perform a Superpave mix design for determination of optimum asphalt content with 35% RAR by weight of binder; and secondly, analyse the performance of RAR modified mixtures prepared using the dry process against Crumb Rubber Modified (CRM) mixtures prepared using the wet process by conducting various laboratory tests. Performance Grade (PG) 64-22 binder was used to fabricate RAR and CRM mixtures and Performance Grade (PG) 70-10 was used to fabricate Control mixtures for this study. Laboratory tests included: Dynamic Modulus Test, Flow Number Test, Tensile Strength Ratio, Axial Cyclic Fatigue Test and C* Fracture Test. Observations from test results indicated that RAR mixes prepared through the dry process had excellent fatigue life, moisture resistance and cracking resistance compared to the other mixtures. / Dissertation/Thesis / Masters Thesis Civil, Environmental and Sustainable Engineering 2018

A reciclagem profunda com adição de cimento Portland é uma técnica de recuperação estrutural e funcional de pavimentos empregada há muitos anos no país, devido a vantagens técnicas, econômicas e ambientais. Contudo, a difusão mais ampla da técnica esbarra na carência de normas e procedimentos nacionais, o que resulta na adoção de variados critérios nos projetos que incluem reciclagem com cimento, às vezes, comprometendo sua eficácia. A pesquisa relatada nesta dissertação teve por objetivo principal estabelecer as bases para a proposição de um método de dosagem para reciclagem de pavimentos com adição de cimento, considerando-se como referência o método de dosagem de materiais estabilizados com cimento da Austroads (2002). Para verificar a validade deste método para materiais de pavimentos brasileiros, desenvolveu-se um programa experimental no qual foram avaliadas propriedades mecânicas (resistência, rigidez e erodibilidade) e volumétricas (retração, absorção, expansão e ascensão capilar) de misturas constituídas por fresado asfáltico, brita graduada e cimento, variando-se a porcentagem de fresado (20% e 50%), o teor de cimento (2%, 4% e 6%), a energia de compactação (Intermediária e Modificada) e o tempo de cura dos corpos de prova (3, 7 e 14 dias). Os resultados dos ensaios mostraram que todas as variáveis analisadas afetam significativamente a resistência à compressão simples, a resistência à tração por compressão diametral e o módulo de resiliência das misturas, enquanto que a retração, a erodibilidade, a absorção, a expansão e a ascensão capilar são afetadas por algumas das variáveis independentes. Dentre outras conclusões, destaca-se que são obtidos elevados valores de resistência à compressão simples (1,61 MPa a 6,08 MPa), resistência à tração por compressão diametral (0,29 MPa a 1,00 MPa) e de módulo de resiliência (10390 MPa a 25719 MPa) com teores baixo (2%) e médio (4%) de cimento, sendo desnecessário e arriscado, pela elevada retração associada, o emprego de teor mais elevado (6%). Ainda, observou-se que o aumento da energia de compactação permite compensar a utilização de teores mais baixos de cimento no que se refere às resistências (à compressão, à tração e à erosão) e módulos obtidos. Globalmente, conclui-se que o método de dosagem de materiais estabilizados com cimento da Austroads (2002) pode ser usado como modelo para o desenvolvimento de um método de dosagem para reciclagem de pavimentos com adição de cimento, sendo necessárias pequenas complementações ou adaptações. O método de dosagem sugerido nesta Dissertação é, ao mesmo tempo, simples o suficiente para ser empregado em laboratórios de canteiros de obra e amplo o bastante para identificar as propriedades mecânicas e volumétricas que devem ser avaliadas ao elaborar-se um projeto de mistura reciclada com cimento. / Full-depth reclamation (FDR) with Portland cement is a technique used for structural and functional rehabilitation of pavements and has been used in Brazil for many years, especially because its technical, economical and environmental advantages. However, a larger diffusion of the technique has been inhibited by the lack of national standards and procedures, resulting in the adoption of different design criteria, which sometimes leads to a low efficiency of the FDR with cement. This research was carried out with the objective of setting the basis for a mix design method for FDR with cement, considering the Austroads (2002) mix design method for stabilized pavement materials as a model. In order to verify the applicability of the Austroads method to Brazilian pavement materials, an experimental program was carried out testing mechanical (strength, stiffness and durability) and volumetric (drying shrinkage, absorption, swell and capillary rise) properties of mixtures made of reclaimed asphalt pavement (RAP), graded crushed stone and cement. Specimens with different RAP contents (20% and 50%), cement contents (2%, 4% and 6%), compacted with two different efforts (Brazilian Intermediate and Modified) were cured for 3, 7 and 14 days. Test results showed that all the studied variables affect the unconfined compressive strength, indirect tensile strength and resilient modulus of the mixtures, while drying shrinkage, erodibility, absorption, swell and capillary rise are affected by some of the independent variables. Among other conclusions, it is pointed out that high values of unconfined compressive strength (1,61 MPa to 6,08 MPa), indirect tensile strength (0,29 MPa to 1,00 MPa) and resilient modulus (10390 MPa to 25719 MPa) may be achieved with low (2%) and intermediary (4%) cement contents, thus making the use of higher (6%) cement content unnecessary and unsafe, due to the higher costs and to the drying shrinkage associated. It was also observed that increases in the compaction effort may compensate the use of lower cement contents as regards to strengths and moduli obtained. Generally, can be concluded that the Austroads (2002) mix design method for stabilized pavement materials may be used as a model for the development of a mix design method for FDR with cement, being necessary only a few additions or adaptations. The suggested method is, simultaneously, simple enough to be used in field laboratories and comprehensive enough for including the mechanical and volumetric properties that must be evaluated when designing a mix for FDR with cement.

Application of recycled concrete aggregates (RCA) has increased recently as a sustainable alternative in concrete construction. Although application of RCA has substantially grown over the past decades, issues related to its structural performance and long-term behaviour still prevent its widespread application, especially in structural purposes. In this study, a new mixture proportioning method called the “Equivalent Volume (EV)” method is proposed for RCA concrete, which is developed on the assumption that the RCA mix is based on a companion conventional concrete mix having the same volume of “cement paste and aggregates” as the companion mixture. RCA mixes containing different aggregate types and mechanical properties were designed using the EV method. Chemical, mechanical and non-destructive tests were performed and their performance was investigated. Finally, a quality control protocol for evaluating the suitability of RCA sources for structural applications is proposed. Results show that the EV method seems a promising approach to mix-proportion eco-friendly recycled concrete mixes. Moreover, the RCA type and properties seem to influence in the behaviour of RCA concrete and thus should be accounted in the mix- design.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / This study aimed to investigate the mechanical and durability properties of recycled aggre-gate concrete with a ternary binder system and optimized mix proportion. Two concretebatches were developed using a densified mix design approach (DMDA) to evaluate therequired mix proportions. Batch I have GGBS content varied at 0%, 10%, 20%, 30%, 40% and50% at constant w/b ratio of 0.45, while batch II concrete mix have varied water/binder ratios:0.3, 0.35, 0.4, 0.45 and 0.5 at constant GGBS replacement level of 30%. The fine aggregate(river sand) of the two batches was blended with fly ash at optimum loose packing density(FA + Sand) and superplasticizer (SP) was incorporated in the mix at a constant level of 1.4%.A control mix comprising of natural aggregate was also developed. The results obtainedshowcased the feasibility of producing structural concrete with recycled aggregates usingGGBS and fly ash. The mechanical and durability properties were best at 30% GGBS contentand 0.35 water/binder ratio. The DMDA for mix proportion adopted for RAC contributed sig-nificantly to improving its properties when compared to NAC, especially at the optimumobserved RAC mix with compressive strength of 52 MPa. Also, the mix demonstrated goodpermeability resistance in terms of chloride-ion ingress and capillary water absorption.

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Yes / Geopolymers have been recognised as a viable replacement to ordinary Portland cement (OPC), providing a cleaner solution since it can significantly reduce greenhouse gas emissions as well as accomplishing effective waste recycling. Construction and demolition waste (CDW) has been recently identified as raw materials for geopolymers due to its availability and high contents of silica and alumina. This paper aimed at reviewing the current state-of-the-art on the geopolymer paste, mortar, and concrete production and their properties, with special attention paid to geopolymers incorporating CDWs. The review covers brief assessment of using CDWs in concrete, the mix design of geopolymer mixtures in addition to identification of the main factors influencing the performance of geopolymer containing CDW. The most recent data related to the mechanical and durability properties of CDW-based geopolymers are presented, while the cost and environmental impacts of using recycled materials in producing geopolymer concretes are also discussed. Geopolymer concretes have a vast range of possible applications, however, there are still several barriers facing commercialisation of geopolymers in construction industry. The review indicated that it is possible to produce geopolymer concretes from CDW-based materials with properties comparable to OPC-based ones; however, the selection of proper material composition should be carefully considered, especially under normal curing conditions.

Workability has traditionally been used as one of the measures for controlling concrete mixture proportioning. This metric has provided limits on the water content in the concrete mixture for given aggregate size and type. The slump test, which is commonly used as an assessment of workability, is not adequate for characterizing the flow behaviour / rheology of fresh concrete. Studies have shown that Bingham's rheological properties, namely yield stress and plastic viscosity, provide good description of the flow behaviour of fresh concrete. In this thesis, an experimental program was designed on the basis of factorial design to evaluate the method of Cement Association of Canada for designing and controlling concrete mixture. The variables included in the mix design are water-cement ratio, water content, coarse aggregate size, silica fume, slag and bulk volume of coarse aggregate. In addition, Neuro-Fuzzy network has been adopted to correlate the current mixture proportioning method to the rheological properties of concrete. The network was constructed using experimental data tested in this study. Such correlation allowed the determination of water-cement ratio, water content, fine aggregate and coarse aggregate from compressive strength, yield stress and plastic viscosity. / Thesis / Master of Applied Science (MASc)