Name: AECIO GUILHERME SCHUMACHER
Type: MSc dissertation
Publication date: 24/08/2018
Advisor:
Name |
Role |
|---|---|
| JAMILLA EMI SUDO LUTIF TEIXEIRA | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| JAMILLA EMI SUDO LUTIF TEIXEIRA | Advisor * |
| PATRÍCIO JOSÉ MOREIRA PIRES | Internal Examiner * |
Summary: Steel slag is a high-strength, low-cost steel by-product material, and it is an alternative to a partial or full replacement of crushed aggregates of mineral origin as a paving material. It presents physical and mechanical characteristics as good as those of granitic rocks, but its expansive nature makes difficult its use. There are treatments applied to the steel slag which can accelerate the hydration reactions, minimizing the expansibility of this material when in service. The evaluation of this expansion potential of the steel slag and its respective effects on the performance of asphalt concrete is essential to verify the technical feasibility of its use. Thus, this work aims in evaluating the influence of steel slag expansion level on the performance of hot mix asphalt (HMA) in early stage. Initially, samples of LD type steel slag with different levels of expansion (6.71%, 3.16%, 1,33%) were submitted to physical, mechanical, and morphological characterization to assess the effects of expansion on individual material properties. Then, steel slag was used as aggregate in HMA to verify the effects of steel slag expansion characteristics on asphalt mixture volumetric and mechanical performance. Four different asphalt mixtures were designed based on Marshall mix design, using asphalt cement (pen. grade 50/70), natural aggregate (granite) and steel slag (in three different levels of expansion). Asphalt mixture´s mechanical characteristics were evaluated based on Marshall stability, indirect tensile strength, and resilient modulus testing results. Also, a modified Pennsylvania Testing Method (PTM) was performed in the studied asphalt mixtures to verify the potential of asphalt binder to encapsulate the expansion potential of steel slag. It was observed that the level of steel slag expansion changes some material´s individual properties which can affect mix design volumetric parameters. In addition, the use of steel slag as an aggregate in CAUQ optimizes the mechanical properties of non-aged asphalt mixtures and minimizes the expansive effects of this material when combined with other components of the asphalt mix.
Keywords: aggregates; steel slag aggregates; hot mix asphalt; expansion;
