Search

A relatively recent development in asphalt pavement technology, warm mix asphalt (WMA) offers a number of benefits. We present a comparison of some mechanical properties of warm mix asphalt (WMA) made in an asphalt plant batch with a traditional Hot Mix Asphalt (HMA). WMA mixture was made with asphalt cement CA 60-70 and a chemical additive that foams the asphalt at 80 °C. WAM was mixed and compacted at 120 °C and 110 °C, respectively. The control mixture (HMA) was a Dense Graded Mixture MDC-19 proposed by [1], was made with the same materials and mixed and compacted at 150 and 140 °C. Mechanical properties were evaluated under two loading modes: monotonic load (Marshall and indirect tensile test) and dynamic loads (resilient modulus, permanent deformation and fatigue). Results showed that mechanical properties of Warm Mixed Asphalts are better than control mixture. [ABSTRACT FROM AUTHOR]

In the world the most used equations in order to predict deformations in unbound granular materials (UGM) of flexible pavement structures are empirical. Many researchís projects have been performed in this area, however the discussion if these equations are reliable have not finished yet. Initially, the paper presents the evolution of some empirical equations developed in order to try to predict the permanent strain accumulation that undergo unbound granular materials (UGM) in cyclic triaxial tests with constant and variable confining pressure (CCP and VCP respectively). Based in the analysis of such equations, the most used in the world were chosen in order to simulate the behavior that underwent a UGM in CCP and VCP tests. The simulations performed, shown that the most part of the empirical equations used to predict the permanent strain accumulation in UGMís can not reproduce the behavior of these materials in CCP and VCP tests. Additionally, the parameters used in such equations are not constants of the material. [ABSTRACT FROM AUTHOR]

In recent years, there has been a significant increase in construction projects in the city of Barranquilla, leading to contamination in soils and water sources due to the inadequate generation and disposal of Construction and Demolition Waste (CDW). It is clear that this is not a local problem alone but that it involves trends present at a global level, which have led several countries to design measures for an adequate management of waste generated on building sites. Some examples of this adequate management are: reincorporation of CDW in construction processes, reuse or use of CDW as raw materials, processing of CDW to be converted into mineral aggregates for concrete and asphalt and the use of CDW as mineral fillers. In this work we present results of a study carried out in 75 construction sites located at different areas of the city of Barranquilla. We have carried out a detailed survey to assess the management, treatment and final disposal procedures, thus leading to a clear identification of relevant issues to deal with in this field, as well as improvements in the knowledge in the local legislation for the management of CDW. Based on the results obtained here, we have identified that the CDW management practices that the construction guild is currently carrying out are not adequate to solve these problems and that a more practical and long term solution needs to include a proposal to improve the management model (involving use and transformation) and its posterior implementation in the city of Barranquilla. [ABSTRACT FROM AUTHOR]