STUDY ON HIGH ELEVATION PUMPED CONCRETE AND ITS APPLICATION TO YANPU BRIDGE IN SHANGHAI

摘要

Yangpu Bridge is a cable-stayed bridge with the longest span of its kind in the world. Its main towers rise 208m above its base, concrete C50 prepared according to design specifications was required to have a smaller creep coefficient. Third paper puts stress on the study of preparation of high elevation pumped concrete and its application to the main towers.Based on correlation between pore distribution and water-cement ratio, suitable water-(cement + fly ash) ratio (W/(C + F))was adopted to control creep coefficient of concrete. In the light of rheological theory of pumped concrete, characterristics and parameters of pumpability of high elevation pumped concrete were proposed and high elevation pumping admixtures suitable for two different kinds of fly ashes were studied. By testing rheological parameters of the concrete, technical measures for controlling dilatancy and optimum aggregate gradation of the concrete were presented to enable the concrete with high performances to be pumped successfully to a height of 208 meters with single step pumping.