极旱、大温差地区养护方式对混凝土桥墩性能的影响

为研究极旱、大温差地区不同养护方式及不同养护天数下混凝土桥墩的强度及抗渗性、微观孔结构之间的关系,选择4种养护方式及3个养护天数(7,14,28 d)对试验桥墩进行了研究。在龄期28 d时对混凝土桥墩的强度、抗渗性和微观孔结构进行了测试和分析,结果表明:按照自然养护、土工布养护、新材料养护、标准养护的顺序最可几孔径及多害孔不断减小,抗渗性逐渐增强;随着养护天数的增加,混凝土的抗渗性、强度、多害孔逐渐下降;养护天数>14 d时,混凝土桥墩各项性能良好,建议养护天数为14 d;新材料养护优于土工布养护,在极旱、大温差地区养护方式的保湿效果越好混凝土桥墩的抗渗性及强度越高。

Effects of Curing Methods on the Performance of Concrete Bridge Piers in Extremely Dry Area with Large Temperature Difference

The relationship among strength, impermeability, and micro-pore structure of concrete bridge pier cured with four different methods at three different curing ages (7d, 14 d, 28d) is examined in extremely dry area with large temperature difference. The strength, impermeability and pore structure of concrete pier are tested and analyzed on the 28^th day of curing. Results demonstrate that the most probable pore and the harmful pore in natural curing condition are the largest, followed by those under geotextile curing, new material curing, and standard maintenance in sequence, indicating an improvement of impermeability. With the increase of curing age, the impermeability, strength, and harmful pore of concrete gradually decline; when curing age exceeds 14 days, the concrete pier performs well, hence we suggest curing for 14 days. New material is superior to geotextile in maintenance. Better moisturizing effect of curing method could result in higher strength and impermeability.