Evaluation of light transmittance performance of light-transmitting concrete with optical fibre

Abstract

Light incidence angle is an important parameter to Light-transmitting Concrete (LTC), especially when it is used for building materials exposed to sunlight. Yet, there is a lack of deeper understanding on the performance of LTC when light incidence is encountered with different angles. This study covers the synergistic effect of light incidence angle, fibre spacing, and fibre diameter on the light transmittance of LTC. Optical fibres with different diameters and spacings are incorporated into the LTC specimen. Light transmittance is measured using a light meter, where the test is conducted in a tight enclosed wooden board. The results show that, as the fibre diameter becomes larger in the LTC, the light transmittance increases. The highest transmittance of 1.613 % was found for LTC with a fibre diameter of 2 mm. In contrast, the light transmittance decreases with the increase in fibre spacing and light incidence angle. It was found that LTC with a 2 mm fibre diameter shows a significant difference with other fibre diameters even at the light incidence angle of 30°. Besides, the effect of fibre diameter on light transmittance was found to be more significant as compared to fibre spacing.