ZEMCH 2019 International Conference Proceedings April.2020 | Page 102
1. Introduction
1.1. Research Objective
Transparent soundproof walls supplying the sunlight and landscape can prevent accidents by
securing drivers’ view when entering road from intersection. Especially, they are increasingly used in
urban areas for aesthetics. The photovoltaic soundproof module can block noises and also generate
electric energy by applying solar cells to the existing transparent soundproof walls. Especially, owing
to its diverse strengths like no necessity of additional structure as it can be installed in the existing road
facilities, the use of idle site, and supply of environment‐friendly energy for the establishment of the
future smart roads, it is actively used by advanced countries like Germany, US, and Japan 1) .
For these reasons, recently several researches on soundproof PV modules are reported. Also,
application cases are actively reported overseas. However, it is still hard to find relevant researches in
Korea. This study aims to suggest basic performance data of soundproof PV modules for transparent
soundproof walls and to evaluate the power performances and also the development of more effective
system.
2. Preliminary Research
2.1. Materials and Basic Performances of Transparent Soundproof Wall
The main materials of transparent soundproof wall are glasses (laminated or tempered) and resins
(polycarbonate or polymer synthetics). Generally, resins are excellent at heat and cold resistance,
transparency and dimensional stability, but they are poor at abrasion resistance and surface strength.
In particular, when the resins are long‐exposed to outdoor environments, it is possible to face yellowing
and lowering transparency. Therefore, they require photo stabilizer treatment for UV block and hard‐
coating for strengthening the surface. Glass materials have better lighting transmission, weather
resistance, chemical and abrasion resistance than resin materials, but they are vulnerable to impact
fracture 6) .
Figure 1. Yellowing of PC and Fracture of Glass
The basic performances of a transparent soundproof wall (barrier wall) include durability, visible
clarity, sound transmission loss and structural stability (allowable displacement and impact resistance).
A material should guarantee over 20 years of durability, has less than 14 of yellowness index in 10 years
and more than 85(%) of visual clarity (KS F 2514). The sound transmission loss requires more than 25(dB)
at 500(Hz) and more than 30(dB) at 1,000(Hz) (KS F 2808). In terms of impact resistance, complete
fracture should not occur after drop impact test (KS F4770‐1). Regarding maximum allowable
displacement, a material which has less than 50(mm) of elasticity displacement and less than 1/500(mm)
of permanent residual displacement of test sample length after deformation test (KS F 4770 –3) 8) .
Table 1. Basic Performances
Test Name
Sound Transmission Loss
91
Scale
dB
Performance Criteria
500 Hz
25 dB
ZEMCH 2019 International Conference l Seoul, Korea