Evaluation of mechanical properties and carbonation of mortars produced with construction and demolition waste. (10th February 2018)

• Record Type: Journal Article
• Authors: de Oliveira Andrade, Jairo José; Possan, Edna; Squiavon, Jéssica Zamboni; Ortolan, Tiago Luis Possebon
• Is Part Of: Construction & building materials. Volume 161(2018)
• Page Start: 70
• Page End: 83
• Publication Date: 2018-02-10
• Subjects: Construction and demolition waste -- Mortar -- Mechanical properties -- Carbonation -- CO2 uptake; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2017.11.089
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Carbonation and mechanical properties of mortars produced with recycled aggregates were evaluated. Five replacement levels and two types of fine recycled aggregates obtained from CDW were analyzed. Statistical analysis (ANOVA) and mathematical modeling were used to analyze the results. The increase in replacement levels of natural aggregate by recycling reduces the compressive strength of mortars. Mortars produced with recycled aggregates showed better CO2 uptake performance due to carbonation. Abstract: The large amounts of waste generated by the construction sector pollute the environment owing to a lack of suitable disposal sites for construction and demolition waste (CDW) and improper methods of disposal. However, these problems provide an incentive to develop recycling alternatives. In pursuit of such alternatives, this study compares the mechanical properties and carbonation depths of mortars produced with two different types of recycled aggregates (RAs): ceramic recycled aggregate (CRA) and mixed recycled aggregate (MRA). The mechanical properties (compressive, flexural, and adhesive strengths), physical properties (porosity, water absorption, and bulk density), carbonation depth over time, and CO2 uptake were evaluated for mortars made with both the types of aggregates. The mortars evaluated were mixed with different levels of RAs used to replace the natural aggregate (25%, 50%, 75%, and 100%). The results showed that as the natural aggregate was replaced with greater portions of RA materials, the compressive strengths of the mortars were reduced, and increases in the carbonation depths of the mortars were observed for all the sample ages analyzed. The results indicated that the bond strength of a mortar with CRA was higher than that of the natural aggregate reference mortar. The mortars produced with CDW exhibited higher CO2 uptake potential, being able to sequester up to 170 g.CO2 /m 2 of coating. Overall, this study illustrated that the use of CDW as a source of fine mortar aggregates can be considered a valid and sustainable alternative for use in construction.