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

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.

Experimental investigation of engineering properties of silica sand filled mortars containing high doses of SWCNT

“…In addition, the ratio of silica sand in the cement mixture of the SS sample prevented the increase in the pore size in the matrix and contributed to the formation of dense structure. Furthermore, Huynh et al [50] reported that the silica content in the cement paste prevented the formation of cracks in the concrete sample. Accordingly, the absence of cracked structures in the SEM images of the silica sand filled SS sample can be attributed to the silica content in the cement mixture.…”

Advances in Laser Materials Processing

“…Laser surface treatment to repair surface defects and cracks in irons, steels, and composites [13][14][15][16]; 3.…”

“…A square, top-hat (flat-top) shaped intensity distribution in the laser micro polishing tool steels [12]; • Laser scabbling to remove the defect surfaces of cement mortar composites [13]; • Laser melting to bionically repair thermal fatigue cracks in ductile iron [14];…”

“…In laser scabbling with a pulsed laser with a power density of 1.45 × 10 5 W/mm 2 , the effects of silica sand proportion in color changing and penetration depth samples were studied for the five types of cement mortar samples, mainly composed of CaO and SiO 2 [13]. Increasing the silica sand proportion resulted in a decrease in scabbling penetration depth and fewer surface cracks on the top and bottom surfaces.…”

An experimental investigation of laser scabbling on cement-based materials using nanosecond fiber laser

“…The concrete spalling was also confirmed as a major mechanism by this laser scabbling method. Moreover, Huynh et al 25 carried out laser scabbling on cement mortars to study the effect of silica sand proportion on scabbling depth and change in color inside the scabbled zone.…”