tailieunhanh - Virtual Pervious Concrete: Microstructure, Percolation, and Permeability - Dale P. Bentz

Virtual Pervious Concrete: Microstructure, Percolation, and Permeability presents various virtual pervious concrete microstructural percolation characteristics and computed transport properties to those of real world pervious concretes. Of the various virtual pervious concretes explored in th is study, one based on a correlation filter three dimensional reconstruction algorithm clearly provides a void structure closest to that achieved in real pervious concrete. | ACI MATERIALS JOURNAL TECHNICAL PAPER Title no. 105-M35 Virtual Pervious Concrete Microstructure Percolation and Permeability by Dale P Bentz As the usage of pervious concrete continues to increase dramatically a better understanding of the linkages between microstructure transport properties and durability will assist suppliers in mixture proportioning and design. This paper presents various virtual pervious concrete microstructural models and compares their percolation characteristics and computed transport properties to those of real world pervious concretes. Of the various virtual pervious concretes explored in this study one based on a correlation filter three-dimensional reconstruction algorithm clearly provides a void structure closest to that achieved in real pervious concretes. Extensions to durability issues such as freezing-and-thawing resistance and clogging that use further analysis of the virtual pervious concrete s void structure are introduced. Keywords freezing-and-thawing microstructure percolation permeability pervious concrete void. INTRODUCTION In the first years of the twenty-first century in the . renewed interest has been expressed in pervious concrete pavements mainly due to environmental According to Reference 1 these materials have actually been used for over 30 years in England and the . and are also widely used in Europe and Japan as a roadway surface course to reduce traffic noise and improve skid resistance. Basically a pervious concrete is simply produced by removing the fine aggregates from a concrete mixture and often using a much narrower distribution of coarse aggregates leading to an increased voids content typically on the order of 15 to 30 . These voids are at least partially connected percolated so that the pervious concrete not only has dramatically increased permeability to allow water penetration and filtration but also lower strength and potentially lower durability. As the volume of pervious concrete .