Name: SIDINEIDY IZOTON
Type: MSc dissertation
Publication date: 13/05/2020
Advisor:
Name |
Role |
|---|---|
| JAMILLA EMI SUDO LUTIF TEIXEIRA | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| JAMILLA EMI SUDO LUTIF TEIXEIRA | Advisor * |
| PATRÍCIO JOSÉ MOREIRA PIRES | Co advisor * |
| RONALDO PILAR | Internal Examiner * |
Summary: Sustainable alternatives for paving materials have been increasingly studied to minimize the extraction of deposits and to reuse by-products and waste already available in yards or landfills. Steel slag has been shown to be technically viable as it has physical and mechanical characteristics similar or even superior to those of crushed aggregates of natural origin, such as granite rocks. However, its use is still limited due to its expansive nature, which can lead to the appearance of early cracks in pavements. Thus, this work evaluates the influence of the expansion of steel slag on the performance of asphalt mixtures in the long term. Three samples of LD type steelmaking slag with different expansion levels (1.63%, 2.31% and 5.92%) were submitted to physical, mechanical and morphological characterization to be evaluated the effects of the expansion on the individual properties of the material.
Furthermore, four asphalt mixtures were produced, one with 100% natural aggregate and the other three with replacement of 25% of natural aggregate by LD slag at different levels of expansion. For the analysis of the different levels of long-term expansion, different aging methods were adopted (outdoors and in laboratory), and tensile strength tests were performed. Moisture-induced damage tests (MID) were
also carried out to verify how the mixtures behave, since water and heat are responsible for the expansion of the steel aggregate. Finally, expansion tests were carried out on the composition of aggregates extracted from asphalt mixtures after aging and conditioning of the DUI. It was observed that the slag expansion process changes some of its properties, highlighting the absorption. Asphalt mixtures with LD with expansion greater than 3% presented lower values of tensile strength and MID compared to other studied mixtures. In general, for the replacement percentages evaluated in this work, the mechanical performance was similar to that of mixtures with 100% natural aggregate and showing satisfactory results.
Keywords: steel slag, expandability, aging, moisture-induced damage, asphalt
mixtures.
