Product Code: ICA12_1807

Surface Glazing of Concrete Using Lasers for Protection and Decommissioning
Authors:
Jonathan Lawrence, Wolfson School of Mechanical and Manufacturing Engineering, Loughborough Univ.; Lincoln Great Britain
Presented at ICALEO 2012

There is renewed interest in using lasers to surface treat concrete. Drivers for this are coming from the architectural and civil engineering sectors, as well as the nuclear industry. CO2 laser, high power diode laser (HPDL) and fibre laser radiation were used to generate glazes on the ordinary Portland cement (OPC) surface of common concrete and the effects thereof on the chemical, physical and mechanical properties of the glazes are described herein. The optimum laser operating parameters window was established along with achievable coverage rates. Compared with 4.3 J for the untreated OPC surface, the rupture strengths of the laser-generated glazes ranged between 0.8 J for the HPDL, 1.5 J for the fibre laser and 1.6 J for the CO2 laser. The pull-off strength of the untreated OPC surface was measured as 63 MPa, whilst for the fibre laser it was 47 MPa, for the HPDL it was 24 MPa and for the CO2 laser it was 11 MPa. The OPC laser glaze exhibited clear improvements in wear and chemical resistance (up to 80% concentration) to nitric acid, sodium hydroxide and detergent. Life assessment testing revealed that the OPC laser glaze had an increase in actual wear life of 1.3 to 22.3 times over the untreated OPC surface of concrete, depending upon the corrosive environment. This investigation has demonstrated that a durable glaze/surface seal can be produced on the OPC surface of concrete that is either long-lasting, or easily removable depending upon the laser used.