Experimental study on 80 MPa grade light transmitting concrete with high content of optical fibers and eco-friendly raw materials

Abstract

Arranging optical fibers with high content in the light transmitting concrete (LTC) helps to enhance the light transmission ability of this material. To develop thinner LTC panels with higher light transmittance, simultaneous improvement of mechanical strength and fiber content is a crucial issue. In addition, since LTC is a material that helps to reduce the environmental impacts, the use of eco-friendly raw materials in the LTC production should also be considered. This study aims to (i) develop the 80 MPa grade LTC with high content of optical fibers and eco-friendly raw materials, (ii) limit the phenomenon of strength reduction with increasing fiber content as in previous studies, and (iii) clarify the effect of temperature, light source distance and fiber diameter on light transmittance of LTC. A series of experiments is conducted to optimize the concrete mixture composition and clarify the mechanical strength, light transmission of LTC samples. The results show that the mixture composition with high workability can be used to develop the 80 MPa grade LTC with an optical fiber volume content of up to 7.1 %. The Scanning Electron Microscope observation results show no significant gaps around optical fibers in the highest content case. The diameter, content, and orientation of the optical fibers do not significantly affect the compressive and flexural strength of LTC. In addition, the results of scattering characteristics of light passing through optical fibers show that the LTC with small diameter fiber suits for wide area illumination and the one with the larger diameter fiber suits for illuminating high-intensity light in a narrow region.