Concrete With Recycled Aggregates For Roads

CONCRETE WITH RECYCLED AGGREGATES FOR ROADS Authors: Bolla, Gustavo Luis; López, Patricia V.; Facendini, Susana R. Professors at Universidad Tecnológica Nacional – Career of Civil Engineering Almafuerte 1033-Paraná-Argentina bollagustavo@arnet.com.ar Key words: Concrete, pavements, CDW, recycled aggregates. Abstract Currently, to rehabilitate and construct roads it is vital to minimize energeticcosts and environmental impact, especially those originated in the exploitation of materials and transportation. One of the ways to do it is the usage of CDW (construction and demolition waste) in new works. In this work, a comparative study between a conventional concrete and concretes elaborated with thick recycled aggregate in different proportions is carried out to be applied to roadconstruction. To that end a crushed aggregate originated in demolition of collapsed rigid pavement was used. The other materials composing concrete were of commercial origin, the diverse batches being elaborated with identical techniques. Waste volumes generated at demolition stage were determined and the process of separation, crushing, shaking and storing of granular material apt to be reutilized wasreproduced at laboratory scale. Physical and mechanical characteristics of component materials were analyzed. The intended concretes were elaborated with different proportions of recycled arid, and resistance to simple compression, resistance to flexion, and resistance to traction per diametric compression were studied analyzing the obtained results comparatively and statistically.

Resumen En laactualidad, para la rehabilitación y construcción de carreteras es imprescindible minimizar los costos energéticos y el impacto ambiental; fundamentalmente los generados por la explotación de los materiales y el transporte. Una de las formas, es la utilización de los RCD (residuos de la construcción y la demolición) en las nuevas obras. En este trabajo se realizó un estudio comparativo entre unhormigón convencional y hormigones elaborados con agregado grueso reciclado en diferentes proporciones, para ser aplicados a la construcción de carreteras. A tal fin se utilizó agregado triturado proveniente de la demolición de pavimentos rígidos colapsados. Los demás materiales componentes del hormigón fueron de orígen comercial, elaborándo los diversos pastones con idénticas técnicas. Sedeterminaron los volúmenes de los residuos que se generan en la etapa de demolicion, reproduciéndose a escala de laboratorio el proceso de separacion, trituracion, zarandeo y acopio del material granular apto para ser reutilizado. Se analizaron las características físicas y mecánicas, de los materiales componentes. Se elaboraron los hormigones previstos con distintas proporciones de árido reciclado, y seestudió la resistencia a la compresión simple, la resistencia a la flexión y la resistencia a la tracción por compresión diametral, analizando comparativamente y estadísticamente los resultados obtenidos.

Introduction: In the province of Entre Ríos, Argentina, important quantities of CDW are produced as a result of concrete road repair, which are scattered indiscriminately in the work area ofinfluence producing environment contamination. In particular, during 2004-05, 0.87 Tn/Km/yr of waste produced by concrete pavement milling and demolition has been recorded, totalizing approximately 1000 Tn annually having no particular purpose (1). In this case, a waste generated by the concrete pavement demolition in the access stretch to the Uranga-Silvestre Begnis Subfluvial Tunnel in the ParanáRiver has been evaluated, and the feasibility of its reutilization as component of a new concrete pavement has been investigated.
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2. The following steps were followed: Analysis, separation and crushing of waste at laboratory scale; characterization assays of material to be recycled and of commercial materials according to ASTM, and local IRAM (Argentine Institute of Standardization and...