浇筑式钢桥面铺装层推挤变形病害机理分析

以贵州省北盘江大桥钢桥面铺装层推挤变形病害为研究背景,采用凝胶渗透色谱法(GPC)和傅里叶变换红外光谱法(FTIR),从沥青分子尺度分析钢桥面铺装产生推挤变形的原因。分析结果表明:沥青老化并不是造成钢桥面铺装层推挤变形的主要原因;从现场调查可知,第2层粘层粘结能力的降低是造成钢桥面铺装层推挤变形病害的次要原因;通过级配分析发现,造成钢桥面铺装层推挤变形的主要原因是浇筑式沥青混合料(GA)级配偏细以及GA中集料颗粒的棱角性较差所致。

Failure mechanism of shoving on steel bridge deck with gussasphalt overlay

To better understand the failure mechanism of shoving on steel bridge deck overlay and guide the maintenance actions, an investigation was conducted on the performance of Beipanjiang bridge in terms of pavement shoving in Guizhou province. The Gel permeation chromatography (GPC) and Fourier Transfer Infrared (FTIR) spectrum were employed to analyze the failure mechanism of shoving from the point of molecular scale. The results showed that the asphalt aging is not the main cause for resulting in the formation of shoving disease on steel bridge deck. In addition, the reduction of adhesive strength of the second tack coat is a secondary cause for shoving disease of the steel bridge deck from the field survey research. Further, sieve analysis was performed to investigate the shoving mechanism on steel bridge deck with Gussasphalt (GA) mixture, and the results indicated that shoving failure is due to the gradation of GA mixture and poor angularity of aggregate particle rather than aging of asphalt binder.