A comparative study of the surface glaze characteristics ofudconcrete treated with CO2 and high power diode lasers.udPart I: glaze characteristics

摘要

This present work describes the differences in the characteristics of glazes generated on the ordinaryudPortland cement (OPC) surface of concrete by means of CO2 and high power diode laser (HPDL)udradiation. The value of such an investigation would be to facilitate the hitherto impossible task ofudgenerating a durable and long-lasting surface seal on the concrete, thereby extending the life andudapplications base of the concrete. The basic process phenomena are investigated and the laser effectsudin terms of glaze morphology, composition, phase and microstructure are presented. Also, theudresultant heat affects are analysed and described. The glaze generated after HPDL interaction wasudfound be fully amorphous in nature, whilst the glaze generated after CO2 laser interaction was seen toudbe of a semi-amorphous structure, with sizeable areas, randomly located within the glaze, displayed audsomewhat regular columnar structure. This is proposed to be due to the differing solidification ratesudoccasioned by each laser after treatment as a result of differences in the beam absorption lengths.