Terry Lambert MSE PE

Thesis: Elucidation of a Concrete Admixture Resistant to Radon Transport Using a Fractional Factorial Experimental Design [DOE] Protocol

Terrence Lee Lambert, Master's candidate, University of Wisconsin - Milwaukee, 1999
A fractional factorial experimental design [DOE] protocol, also known as the Taguchi method, was employed to statistically ascertain the preferred tested level of seven concrete constituents potentially capable of lessening the transport of radon gas in concrete admixtures individually or in combination. The addition of fly ash, bottom ash, slag, silica fume, crumb rubber (ground tires), superplasticizer and two different water to cement ratios were analyzed via the radon transport properties of sixteen distinct concrete admixture formulations. The following concrete properties were measured: the radon diffusive transport coefficient: air permeability coefficient and percent porosity. By utilizing the diffusion results, the fractional factorial experimental design method employed statistically suggested a "best" formulation from among a possible 27 (i.e., 128, the total possible combinations of seven factors taken at two different levels). Diffusion coefficient measurements were calculated by detecting the amount of radon flux that passed through the samples over three 16 and three 24 hour periods. Three distinct concrete formulations were elucidated by using the mean diffusion coefficient from the 16 hour runs. the 24 hour runs and all runs taken together. Samples were then prepared from the suggested formulations and the radon transport properties were measured. Two of the elucidated formulations exhibited superior resistance to radon transport with significantly lower diffusion coefficients than those of a traditional concrete mix and any of the other concrete formulations tested herein. One of the elucidated formulations also expressed superior permeability and porosity values. The results of this thesis conclude that waste materials can be effective admixture constituents by substantially reducing the radon transport properties of concrete. These results can be applied to new home construction to reduce the accumulation of radon in indoor air.

The Evolution and International Acceptance of the Moratorium on Radioactive Waste Dumping in the Ocean

Terrence Lee Lambert, Univerity of Wisconsin System United Nations Summer Research Affiliate, 1999
How small island nations were influential in securing an international moratorium prohibiting radioactive waste dumping in the ocean.