Application of Lightweight Aggregate Concrete in Old Bridge Deck Pavement Engineering

In terms of the severe phenomena arising in the bridges of our country in recent years, like decrease of bearing force, loss of pre-stress and damage of bridge deck, this paper studies the application of lightweight aggregate concrete in the old bridge deck pavement from the aspects of concrete preparation, construction technics and quality control, and probes into the key technologies and anti-crack measures for lightweight aggregate concrete construction. The study result indicates: adopting the paving pattern of "shear connector + steel fabric + lightweight aggregate concrete" can resolve the issues of old bridges in decrease of bearing force and damage of bridge deck; pre-wetting lightweight aggregate and mixing polypropylene fiber into it can improve its early-age crack resistance; adopting macadam ceramsite whose shear strength exceeds 6.0 MPa can prepare the lightweight aggregate concrete with apparent density up to 1900~2000kg/m3, 28d compressive strength up to 48Mpa, flexural strength up to and elastic modulus exceeding 30GPa, which has been successfully applied to Fenjiang Bridge in Fokai Freeway of Guangdong province.