José Camapum de Carvalho

THE USE OF QUARRY WASTE IN PAVEMENT CONSTRUCTION

Abstract This paper presents the study of quarry wastes aiming their utilization as the main material for the base layer of flexible pavements. The material was characterized by laboratory tests, to evaluate its utilization potential. In order to evaluate its field behavior, an experimental road segment (80 m) was constructed, encompassing subgrade, base (20 cm) and surface treatment (3 cm). Then, ‘in situ’ tests such as field California Bearing Ratio (CBR), Dynamic Cone Penetration (DCP), plate loading, Pencel pressuremeter, Benkelman beam and Falling Weight Deflectometer (FWD) tests were performed. Since its construction in July 1998, it has been observed that although performance indices have reduced, no significant structural damages have resulted. Structural deterioration occurred mostly during the rainy season, when the moisture content of the material increases. Up to the current time, the results indicate that this quarry waste has a reasonable potential for use as construction material for the base layer of flexible pavements. The quarry waste material evaluated in this study seems to be more appropriate to low-volume roads.

Use of Locally Available Soils on Subbase and Base Layers of Flexible Pavements

Lateritic soils are very abundant in the region of the Federal District of Brazil. If this material could be used in low-volume roads, it would be possible to avoid some environmental problems. Alternative techniques were developed for the use of nonconventional materials as subbase and base layers of flexible pavements. To analyze the technical and economical viability of using local soils, two experimental highways were constructed. Each highway was divided into three sections with different materials in the subbase and base layers, such as fine lateritic soil, fine lateritic soil stabilized with lime, and a mixture of fine lateritic soil and crushed rock. The compaction characteristics were evaluated in laboratory tests. From the time the segments were constructed (in 1998 and 2000) until 2001, the stress–strain behavior of the paving structures was evaluated by in situ tests, such as the plate-bearing, Benkelman beam, and falling weight deflectometer tests. From the results, conclusions were drawn about which of the chosen materials showed the best performance in mechanical behavior.

Field Investigation of Mechanic Properties of Recycled CDW for Asphalt Pavement Layers

AbstractConstruction and Demolition Wastes (CDW) have been reused in many engineering works. This paper focuses their use in asphalt pavements by monitoring a real road with different types of field tests over eight years. The parameters obtained presented the same level of the natural granular materials traditionally used and showed the technical potential of the CDW aggregate mixtures for subbase and base layers.

Chapter 26 The use of alternative and improved construction materials and geosynthetics in pavements

Abstract Traditional construction materials can be scarce or very expensive for several civil engineering works. Nowadays, significant increases in the cost of construction materials can also be a consequence of environmental restriction to their exploitation. Thus, there is an increasing interest on the use of low grade construction materials in pavements and other earth works. This work deals with the use of alternative materials for the construction of pavements in association with low cost geosynthetics. Field test sections in a highway were constructed and monitored to evaluate the performance of the following pavement solutions: fine-grained soil stabilised with lime, quarry waste, poor quality fill material enveloped by a nonwoven geotextile impregnated with asphalt, geotextiles as separation between the pavement base and the subgrade and between the base and the asphalt cap. A control test section where the pavement was constructed using good quality gravel was also monitored. Several laboratory and field tests were performed throughout the research, such as laboratory tests under unsaturated conditions, field plate load tests, field CBR and pressuremeter tests. The results obtained show the potentials of the use of low grade construction materials when appropriate construction procedures and geosynthetics are employed.