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Quantitative Analysis of Surface Attached Mortar for Recycled Coarse Aggregate
Guoying Liu1, Qiuyi Li1, Jialin Song2
1School of Architectural Engineering, Qingdao Agricultural University, Qingdao 266109, China.
Materials (Basel, Switzerland)
|January 11, 2022
Summary
Physical strengthening techniques effectively improve recycled coarse aggregate quality by removing attached mortar and micro-powder. This process enhances properties like water absorption and density, making recycled aggregate more comparable to natural aggregate.
Area of Science:
- Civil Engineering
- Materials Science
Background:
- Recycled coarse aggregate (RCA) quality is limited by attached hardened cement mortar and micro-cracks.
- Properties like water absorption, apparent density, and crushing index of RCA are inferior to natural coarse aggregate.
Purpose of the Study:
- To evaluate the effectiveness of physical strengthening techniques on RCA performance.
- To determine the relationship between attached mortar content and RCA quality.
- To identify optimal parameters for physical strengthening.
Main Methods:
- Physical strengthening using mechanical action to remove surface mortar and micro-powder.
- Performance testing of RCA before and after strengthening.
- Analysis of RCA quality across different classes (I, II, III) based on mortar content.
Main Results:
- Physical strengthening significantly improves RCA quality by removing adhered mortar.
- Optimum calcination temperature was 400°C with a 20-minute grinding time.
- RCA quality is directly correlated with attached mortar content (7.9% for Class I, 22.8% for Class II, 39.7% for Class III).
Conclusions:
- Physical strengthening is a viable method to enhance RCA properties.
- Reducing attached mortar content is crucial for improving RCA performance.
- Optimized strengthening parameters yield superior RCA quality.
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