Most Popular Books by David Rhodes

Every day, you likely will encounter a TON of advertisements. Some obvious ones (like billboards), and some less obvious ones (like the tee your favorite character wears!). Ads entice us to want to be part of the media we love most, and that's not a bad thing! But...we can't be a part of everything, right? Open this book to learn about ads, good questions to ask, and powerful decisions you can make about the products and companies you support.  Core themes in this book: Choice, Expression, Power, Wants Meet A Kids Co., a new kind of media company with a collection of beautifully designed books that kickstart challenging, empowering, and important conversations for kids and their grownups.

Every year several prestressed concrete (P/C) girder bridges are damaged by overheight vehicles. Traditional P/C girder repair strategies include beam replacement, internal strand splices, external post-tensioning, and welded steel jackets. Unfortunately, these types of repairs are both labor intensive and vulnerable to future corrosion. One possible alternative to these traditional repair techniques is to repair/strengthen impact damaged P/C girders with carbon fiber reinforced polymers (CFRP). These types of materials have the advantage of large strength/weight ratios, excellent corrosion/fatigue properties, and are relatively simple to install. This report describes the experimental results from three full-sized P/C beams that were intentionally damaged to simulate vehicle impacts, repaired, and tested. Damage consisted of removing concrete from the bottom flange and severing a number of prestressing strands. The beams were strengthened/repaired by patching the bottom flange and installing multiple layers unidirectional CFRP to restore the original flexural capacity. CFRP fibers were also used in the transverse direction to help confine the patch material and to prevent premature debonding of the longitudinal sheets. Service level and ultimate load tests were conducted to determine the effectiveness of CFRP strengthening system. A theoretical analysis of the strengthened/repaired beams was also completed. In addition to the full-size beams, a number of smaller specimens were also used to address durability and environmental concerns related to the use CFRP on bridge structures.