The recycling of industrial wastes in road infrastructures represents a possible solution to two important and delicate questions: the growing problem of disposing of this industrial by-products and the need to find alternative sources to the traditional quarried stone materials used for the road construction. The paper describes an experimental investigation of foamed bitumen bound mixtures for road pavements, with the aggregate matrix completely composed by industrial by-products, as electric arc furnace steel slags, waste foundry sands and bottom ash from municipal solid waste incineration, used with different proportions. The study has been articulated in a laboratory analysis of the physical and leaching properties of the individual recycled granular materials considered and in the following mechanical characterization of the foamed bitumen bound mixtures, in terms of indirect tensile strength tests and stiffness modulus tests. Both the mechanical test have been also performed in wet conditions, in order to investigate the moisture sensitivity of the mixes. The results of the tests (indirect tensile strength and stiffness modulus up to 0.85 MPa and 8567 MPa, respectively, depending on the mixture) have been compared with the requisites for acceptance of the main Italian Contract Specifications, which has demonstrated that the analyzed marginal materials are suitable for use as integral substitutes of the natural aggregates, in the production of foamed bitumen bound mixtures for road pavements.
Foamed bitumen bound mixtures with steel slag, foundry sand and bottom ash: a laboratory investigation
BALDO, Nicola
2011-01-01
Abstract
The recycling of industrial wastes in road infrastructures represents a possible solution to two important and delicate questions: the growing problem of disposing of this industrial by-products and the need to find alternative sources to the traditional quarried stone materials used for the road construction. The paper describes an experimental investigation of foamed bitumen bound mixtures for road pavements, with the aggregate matrix completely composed by industrial by-products, as electric arc furnace steel slags, waste foundry sands and bottom ash from municipal solid waste incineration, used with different proportions. The study has been articulated in a laboratory analysis of the physical and leaching properties of the individual recycled granular materials considered and in the following mechanical characterization of the foamed bitumen bound mixtures, in terms of indirect tensile strength tests and stiffness modulus tests. Both the mechanical test have been also performed in wet conditions, in order to investigate the moisture sensitivity of the mixes. The results of the tests (indirect tensile strength and stiffness modulus up to 0.85 MPa and 8567 MPa, respectively, depending on the mixture) have been compared with the requisites for acceptance of the main Italian Contract Specifications, which has demonstrated that the analyzed marginal materials are suitable for use as integral substitutes of the natural aggregates, in the production of foamed bitumen bound mixtures for road pavements.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
