Title: Remediated Thermal-Treated Soil and Tar-Containing Asphalt as Secondary Filler and Sand in Self-Compacting Concrete

Author(s): Shizhe Zhang, Jeroen Lenderink, Marc Brito van Zijl, Vincent Twigt, Rob Bleijerveld

Publication: Symposium Paper

Volume: 362

Issue:

Appears on pages(s): 366-375

Keywords: thermal-treated soil, tar-containing asphalt, recycling, secondary raw materials, self-compacting, concrete

DOI: 10.14359/51740897

Date: 6/11/2024

Abstract:

The shortage of high-quality fine aggregate as an essential component of concrete has become an emerging worldwide concern for the construction industry. Concrete typically comprises up to 30% fine aggregate, which largely influences the strength and durability of the final product. Therefore, finding suitable substitutes for natural fine aggregate has become an important aspect of current concrete research.

In this study, we investigated the suitability of using remediated thermal-treated soil and tar-containing asphalt as secondary raw materials in a self-compacting concrete (SCC) mixture. The remediated materials were used as both (1) fine aggregate replacement to replace all the river sand and (2) partial filler/supplementary cementitious material (SCM) replacement. The modified Andreasen and Andersen (A&A) particle packing model was used to determine the optimal replacement level. Based on the optimal mixture design, the impact of the replacement on the fresh and mechanical properties of SCC was evaluated. Additionally, the pozzolanic reactivity of the fine fraction (<125 μm) within the secondary sand was assessed and compared to that of limestone powder. Our findings confirm that using remediated thermal-treated soil and tar-containing asphalt can produce a more circular, sustainable SCC by replacing high-quality natural sand and limestone filler and reducing the environmental impact of conventional SCC. This study contributes to finding viable alternatives to natural fine aggregate and promotes the use of recycled materials in construction.