Durability of mortars made with recycled fine aggregates under severe sulfate environment

Author(s): S. T. Lee, K. P. Park, J. P. Kim
Paper category: Proceedings
Book title: Proceedings of the 2nd International RILEM/COST Conference on Early Age Cracking and Serviceability in Cement-based Materials and Structures Volume 2
Editor(s): Stéphanie Staquet and Dimitrios Aggelis
ISBN: 978-2-35158-200-8
e-ISBN: 978-2-35158-198-8
Publisher: RILEM Publications SARL
Publication year: 2017
Pages: 901-906
Total Pages: 6
Language : English

Abstract: This study was conducted to investigate the sulfate resistance of plain cement mortar specimens prepared with two
recycled fine aggregates exposed to severe sulfate environments. The mortar specimens were immersed in sodium sulfate and magnesium sulfate solutions for 360 days. Another variable was the different replacement ratios of the recycled fine aggregates. All mortar mixes were made with the water-cement ratio of 0.45 and fine aggregate-cement ratio of 2.0. To monitor the degree of deterioration of the mortar specimens, the performance of the mortar specimens was evaluated by measuring the expansion due to sulfate attack. Investigations indicated that 50% replacement with recycled fine aggregates produced a measurable increase in sulfate resistance of recycled fine aggregate in both sodium and magnesium sulfate solutions. However, severe deterioration by sulfate attack was exhibited, particularly in sodium sulfate solution, in mortar specimens with 100% replacement of recycled fine aggregate with a higher absorption. The tests show that the resistance to sulfate attack of mortar specimens with 100% recycled fine aggregates is very much related to the high absorption of the recycled fine aggregate and to the less densification of the transition zone in the recycle aggregate mortar. Additionally, x-ray diffraction (XRD) analysis clearly showed the deterioration products due to the sulfate attack.

Online publication : 2017
Publication type : full_text
Public price (Euros) : 0.00