Aplicação da metodologia de projeto de experimentos na dosagem de misturas de reciclagem de pavimentos com adição de cimento

Abstract

Nesse estudo foi verificada a aplicação da metodologia de projeto de experimentos na dosagem de misturas de reciclagem de pavimentos com adição de cimento. Adotou-se um método de dosagem que avalia propriedades mecânicas, volumétricas e de erodibilidade, e foram desenvolvidas todas as etapas que contemplam um projeto de experimentos. O planejamento possibilitou definir as variáveis que exercem maior influência nos resultados, de modo a estabelecer uma matriz experimental abrangente e reduzida. Na análise dos resultados foi possível quantificar o efeito dos fatores controláveis estudados (teor de cimento e porcentagem de fresado) em cada variável de resposta. A partir da otimização multivariada, obteve-se o ajuste ótimo dos fatores controláveis considerando todas as variáveis de resposta simultaneamente. A ferramenta adotada nesse trabalho se mostrou bastante eficiente, podendo ser amplamente empregada na otimização de processos, como é o caso da dosagem de misturas recicladas.

A review of full-depth reclamation of pavements with Portland cement: Brazil and abroad

“…Increasing cement contents increase the strength and stiffness of FDR-PC mixtures; the higher the cement content, the higher the hydration reactions, generating bonding points between aggregates [12, 46-48, 50, 67, 70, 75-77, 85, 96, 97, 105, 106]. Cement increase also reduces porosity, which results in less moisture sensitivity and higher durability [80,84,97,104].…”

“…Like any cementitious material, FDR-PC mixtures become stronger and stiffer while curing [13, 21, 47, 75-77, 87, 96, 105]. Besides, their moisture resistance also increases with age [84,104]. In the field, traffic opening usually happens a few hours after recycling (with adequate surface protection applied).…”

“…However, some recommend longer curing times before traffic is permitted. Laboratory studies show that shrinkage effects are stronger in the early stages [72,85,104], which can result in cracks, compromising the quality of the layer. Thus, proper curing is necessary to avoid such problems; this can be achieved by applying a sealing compound or membrane [3].…”

“…Generally, an FDR-PC mixture containing a coarser base material (e.g. graded crushed stone or gravel) will present higher strength and stiffness [50,75,82,84,85,[104][105][106]. However, some authors verified similar behaviour between FDR-PC mixtures with gravel or sand base materials [76], while others reported that higher fines content led to higher strength [97].…”

Fatigue of Cold Recycled Cement-Treated Pavement Layers: Experimental and Modeling Study

“…For the base layer, the data obtained for the CRCTMs were used. The initial thickness was 200 mm and the Poisson's ratio was assumed to be 0.25, following research on CRCTMs by Kleinert [22]. Since the focus of this study was the cold recycled cement-treated layers, MeDiNa default materials were used for the other layers.…”