Title: Design of Engineered Cementitious Composite Link Slab
ISBN: 978-967-2048-12-1 | eISBN:978-967-2048-13-8
Pages: 97 pages
Preface: Highway bridge designs are composed of multiple spans of steel or concrete girders, which are merely supported at piers and bents. A mechanical joint is usually installed toward the end of the simple span deck to allow deck distortions forced by brace avoidance, shrinkage, and temperature adjustment. The deck joint of the bridge is expected to be the most expensive part for installation and maintenance. Water leakage through these joints causes corrosion at the ends of the deck and also at the piers.
Considering the issues concerned with the poor-performance of expansion joints, researchers have investigated jointless decks as a different option. It is believed that the construction and repair of jointless deck slabs are more economical than the installation and repair of expansion joints. Self-compacting ECC link slab is advantageous concerning the ability to fill complex forms with limited accessibility, speedy pumping of ECC, enhances the efficiency and quality. Link slab provides the jointless portion at the conjunction of bridge decks. Since the link slab is continuous on joints of the decks, it fastens the gap between the adjacent spans and avoids rain water from penetrating through the joints and causing corrosion. Unlike ordinary concrete, ECC has a strain capacity in the range of 3% – 7%, compared to 0.1% for Ordinary Portland Cement (OPC) concrete. Therefore, ECC exhibits ductility than a brittle behaviour of conventional concrete in the hardened stage. After the first crack, the composite experiences plastic yielding and strain-solidifying to a ductile strain of 3.5% preceding building up a naturally visible split. This pliable strain limit is around 350 times that of typical cement (0.01%). ECC accomplishes strain hardening by utilizing just a moderate amount of fibres (commonly 2% by volume) as compared to other superior fibre reinforced concretes.