# 2012 Barcelona
Polyethylene (PE) pipes for gas supply, which have been widely used in recent years, have superiority in installability, seismic performance and corrosion resistance, while their resistivity against external force such as from strikes by excavator bucket edges is inferior to metal pipes. Under some installation conditions, it is necessary to take appropriate protection measures for PE pipes. Use of protective steel sheets or concrete plates that are laid directly on pipes is commonly applied. However, they have two problems, which are their poor installability due to their heavy weight and high total cost including installation expense. To resolve this issue, the authors developed a unique PE pipe protective sheeting, which is superior compared to conventional protectors. It is characterized by decreasing the damage to a buried PE pipe surface within the rated value against assumed external force, for instance, due to being struck by an excavator bucket edge. It also contributes to an improvement in installability and workability as well as reduction in total cost including installation expense. This protective sheeting is comprised of two types of materials with different properties, reinforcing fiber and nonwoven material. The reinforcing fiber, which has a superior failure-bearing effect, protects against damage attributable to direct strike by an excavator bucket edge to a PE pipe surface. Nonwoven material is effective in mitigating external force and impact absorption. This product has been applied company-wide since 2007, and has been available in the Japanese market. As of March 2011, over 13,000m2 of this protective sheeting had been installed in Japan.
Author(s) : Asami Nakai, Yoshitaka Tanaka, Akio Ohtani, Shigeyoshi Matsubara, Louis Laberge Lebel, Hiroyuki Hamada
Pultrusion process is one of the composite production methods that have been used for mass production of uniform profiles. However, there are two problems that are commonly found in pultrusion products; one of which is its anisotropic mechanical properties. This anisotropicity stems from the alignment...
Author(s) : Takashi Kuriyama, Kenji Mizukawa, Hiroyuki Kurio, Hiroaki Sakamoto
The Great Hanshin Earthquake that occurred on January 17, 1995, caused devastating damages to a large number of architectural structures such as high-rise apartment houses, and civil structures such as roads and bridges. This earthquake triggered the review of the quake-resistance standards of buildings and civil...
Author(s) : Tanaka, Akiyama, Komukai
This paper describes the influence of residual chlorine in potable hot water on durability of cross-linked polyethylene and polybutene pipes. The aim of this study is to find and verify proper testing procedures and evaluation methods to estimate service lives of plastic pipes under different concentration of residual...