Research on Gas Permeability of Pipe-concrete Interface in Plastic-pipe Confined Concrete

Abstract:

A pressure-time recession method to measure the gas permeability of the pipe-concrete interface in Plastic-Pipe confined Concrete (PPC) was introduced,and then effects of some improving measures on the gas permeability of the pipe-concrete interface in PPC were investigated by this method.Results indicate that this method is of high repeatability and stability.The gas permeability decreases with the increase of the expansive agent.The Preprufe tape greatly improves the bonding property of the pipe-concrete interface,and therefore,the decay time of gas pressure or the gas impermeability is an order of magnitude higher than that of the controlling PPC.Fitting curves of the gas pressure-time recession were conducted and an empirical formula was proposed.

Key words:plastic-pipe confined concrete; interfacial gas permeability; gas tightness; pressure-time recession curve