大掺量粉煤灰海工混凝土耐久性探讨

On Durability of Marine Concrete with High Content of Fly- Ash

在我国北方地区海洋环境下,混凝土结构的腐蚀现象十分严重,采用大掺量粉煤灰来取代水泥,能够获得良好的经济效益和环境效应。掺加粉煤灰能够增加混凝土密实度,进而提高混凝土抗氯离子渗透能力;而且能够减少水泥用量,降低水化热,防止大体积混凝土因水化热过大产生温度梯度而导致混凝土开裂,使得大体积海工混凝土的耐久性得以提高。针对氯离子渗透、硫酸盐侵蚀、冻融循环等破坏作用,对大掺量粉煤灰海工混凝土的耐久性等性能进行了探讨。

The phenomenon of concrete structure corrosion is very serious in the marine environment in north of China. Using large proportion of fly ash to replace cement can obtain better economic benefit and environment effect. High fly ash content concrete not only can increase the compactness of concrete, but also enhance the ability to resist chloride ion permeability. It also can reduce the content of cement and the heat of hydration to prevent mass concrete cracking because of temperature gradient which caused by the high heat of hydration. In this way the durability of Marine concrete can be improved. According to the chloride ion penetration, sulphate erosion, freeze -thaw cycle and other damages of concrete, the durability of concrete with high fly ash content is discussed in the present paper.