硫酸盐对碾压混凝土侵蚀开裂的机理微观分析

Microstructure analysis on mechanism of sulfate attack on RCC

本文通过偏光显微镜和电子显微镜研究了硫酸盐对碾压混凝土侵蚀的机理。研究结果表明:硫酸盐从碾压混凝土裂缝进入是主要侵蚀方式,石膏的形成是主要的破坏形式,添加适宜种类和掺量的氧化镁类膨胀剂,可以增加浆体中的水化产物,以填充水泥浆体的毛细孔以及集料与浆体的间隙,提高密实度,从而提高碾压混凝土抗硫酸盐侵蚀的能力。

The mechanism of erosion in RCC due to sulfate was investigated by means of polarimicroscope and electronic microscope. The formation of gypsum caused by sulfate solution in the crack of concrete is the major cause of cracking. The sulfate resistance of concrete can be promoted by adding expansive agent, such as MgO type additive, to increase the hydration products of cement paste, which will fill the micro pores in mortar and the crevices between aggregate and mortar.