Sulfate attack expansion mechanisms
Sulfate attack expansion mechanisms
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DOI：
10.1016/j.cemconres.2013.07.005
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发表时间：
2013-10-01
影响因子：
11.4
通讯作者：
Heinz, Detlef
中科院分区：
文献类型：
--
作者：
Muellauer, Wolfram;Beddoe, Robin E.;Heinz, Detlef
使用特殊构造的应力盒来测量薄壁波特兰水泥砂浆圆柱体因外部硫酸盐侵蚀而产生的应力。研究了储存液硫酸盐浓度和水泥C(3)A含量的影响。分别通过 X 射线衍射和压汞孔隙率测定法研究了矿物成分和孔径分布的变化。损坏是由于在小孔（10-50 nm）中形成钙矾石，产生高达 8 MPa 的应力，超过了粘合剂基体的拉伸强度。较高的硫酸盐浓度和 C(3)A 含量会导致较高的应力。结果可以从晶体表面能和尺寸对过饱和度和晶体生长压力的影响来理解。 (C) 2013 Elsevier Ltd. 保留所有权利。
A specially constructed stress cell was used to measure the stress generated in thin-walled Portland cement mortar cylinders caused by external sulfate attack. The effects of sulfate concentration of the storage solution and C(3)A content of the cement were studied. Changes in mineralogical composition and pore size distribution were investigated by X-ray diffraction and mercury intrusion porosimetry, respectively. Damage is due to the formation of ettringite in small pores (10-50 nm) which generates stresses up to 8 MPa exceeding the tensile strength of the binder matrix. Higher sulfate concentrations and C(3)A contents result in higher stresses. The results can be understood in terms of the effect of crystal surface energy and size on supersaturation and crystal growth pressure. (C) 2013 Elsevier Ltd. All rights reserved.