*Technical Note* **Aggregate Roundness Classification Using a Wire Mesh Method**

### **Sung-Sik Park 1, Jung-Shin Lee 1 and Dong-Eun Lee 2,\***


Received: 22 July 2020; Accepted: 18 August 2020; Published: 20 August 2020

**Abstract:** Herein, we sugges<sup>t</sup> a wire mesh method to classify the particle shape of large amounts of aggregate. This method is controlled by the tilting angle and opening size of the wire mesh. The more rounded the aggregate particles, the more they roll on the tilted wire mesh. Three di fferent sizes of aggregate: 11–15, 17–32, and 33–51 mm were used for assessing their roundness after classification using the sphericity index into rounded, sub-rounded/sub-angular, and angular. The aggregate particles with di fferent sphericities were colored di fferently and then used for classification via the wire mesh method. The opening sizes of the wire mesh were 6, 11, and 17 mm and its frame was 0.5 m wide and 1.8 m long. The ratio of aggregate size to mesh-opening size was between 0.6 and 8.5. The wire mesh was inclined at various angles of 10◦, 15◦, 20◦, 25◦, and 30◦ to evaluate the rolling degree of the aggregates. The aggregates were rolled and remained on the wire mesh between 0.0–0.6, 0.6–1.2, and 1.2–1.8 m depending on their sphericity. A tilting angle of 25◦ was the most suitable angle for classifying aggregate size ranging from 11–15 mm, while the most suitable angle for aggregate sizes of 17–32 and 33–51 mm was 20◦. The best ratio for the average aggregate size to mesh-opening size for aggregate roundness classification was 2.

**Keywords:** aggregate; classification; wire mesh; roundness; tilting angle; opening size
