Date of Award

12-2012

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Civil Engineering

Advisor

Putman, Bradley J

Committee Member

Rangaraju , Prasada R

Committee Member

Juang , Hsein C

Abstract

Pervious concrete has many environmental benefits, but with these benefits come additional hurdles unseen in conventional concrete. The main focus of pervious concrete is the maintenance of the interconnected pore structure, leading to porosity values between 15 and 25%, while still developing adequate strength. Due to these inherent properties of pervious concrete, development of a systematic optimum mix design method is challenging. Currently, there is a need to develop a systematic optimum mix design for pervious concrete, but it has yet come to fruition. This research focuses on the influence of cement paste on the performance of pervious concrete, and the results could be used to develop a systematic procedure to determine an optimum mix design for pervious concrete.
This research is divided into two different phases. Phase 1 examined the properties of cement paste, independent of aggregate for a range of water-to-cement ratios. Phase 2 evaluated the variation of properties for different cement-to-aggregate ratios. Analysis for Phase 2 also included three different aggregate sources.
Through analysis, the influence of paste viscosity, to develop adequate film thickness, became a major factor. The high flow of the 20% Fly Ash with Superplasticizer mixture developed very different trends to the much stiffer pastes used in the Control and Superplasticizer mixtures. Confirmation of film thickness contributing to these contradicting trends was determined through qualitative analysis. In terms of strength, the paste designs that possessed the higher flexural strength generally resulted in pervious concrete mixtures having higher compressive strength values. Through the various aggregate sources tested, it was determined that aggregate source does influence the properties of pervious concrete, but generally results in similar trends.

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