*Article* **The Effect of Silica Sand Proportion in Laser Scabbling Process on Cement Mortar**

**Tam-Van Huynh 1, Youngjin Seo 1 and Dongkyoung Lee 1,2,3,\***

> **\***


+82-41-521-9260

3 Center for Advanced Powder Materials and Parts of Powder (CAMP2), Kongju National University,

> Tel.:

Cheonan 31080, Korea Correspondence: ldkkinka@kongju.ac.kr;

**Abstract:** Cement mortar composite has a wide range of applications on construction sites, including masonry, plastering and concrete repair. In construction sites, scabbling process is a method to remove from a few millimeters to several centimeters of defect concrete surfaces. As a result, it is essential to investigate the scabbling characteristics for cement mortar with different silica sand proportion in laser scabbling process. In this study, 5 types of cement mortar with different silica sand proportions in mixing were fabricated and scabbled by using a high-density power laser beam. The effects of silica sand proportion in color changing and penetration depth of the samples after laser scabbling process were studied. Furthermore, the generation of micro-cracks and pores were observed by using scanning electron microscopy (SEM). In addition, chemical composition changes between processed zone and non-processed zone were also evaluated by Energy Dispersive X-ray (EDX) analysis. The results of this study are expected to provide valuable knowledge in understanding of the laser scabbling process for cement-based materials.

**Keywords:** cement-based material; laser scabbling; microstructural analysis; chemical analysis; thermal properties
