Laboratory measurements of electro-osmotic pulsing technology in reducing radon soil gas diffusion through a concrete slab

This paper presents the experimental results of utilizing Electro-Osmotic Pulsing Technology toreduce the diffusion of radon soil gas through a concrete slab. A laboratory system with state-of-theartinstrumentation has been used to measure the diffusion coefficient of radon soil gas through 30.5cm diameter, 10.2 cm thick standard composition concrete samples (w/c = 0.5 and cement:sand:gravel= 1:2:4). Within these concrete samples, a triple titanium anode configuration is embedded while anexternal copper rod is used as the cathode. To complete the circuit, these electrodes are connected to aunique variable pulsating power supply. This unique control processor generates a variable waveformsequence of positive, negative and neutral applied voltages with a variable pulse duration and currentamplitude. In the test apparatus, the Source Chamber is filled with Antigo Silt Loam Soil, typical ofWisconsin soils and a passive radon gas source. The concrete sample is placed between this SourceChamber and a Collection Chamber so that the frontal facial area of the concrete sample is adjacent tothe soil and radon gas flux. The rear facial area of the concrete slab is exposed to quiescent air.The experimental results show as much as a 93% reduction in the radon soil gas diffusion coefficientthrough the concrete slab when the Electro-Osmotic Pulsing System (EOPS) is in operation. Theeffects of system operation, voltage waveform sequence, pulse duration as well as soil and concreterelative humidity levels are documented. Details of the innovative experimental system andprocedures are described. The results of this study have indicated that Electro-Osmotic PulsingTechnology should be considered as an effective and alternative method of reducing radon soil gasdiffusion in buildings.