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初步研究了磷铝酸盐水泥(phosphoaluminate cement,PALC)的抗硫酸镁侵蚀性能,同时与硅酸盐水泥(portland cement,PC)浆体进行了比较,并利用X射线衍射、核磁共振等测试方法对水泥水化浆体微观组成进行分析。结果表明:PLAC呈现优异的力学性能和抗硫酸盐侵蚀的能力。在硫酸镁溶液中腐蚀360,510d时,PALC砂浆的抗蚀系数分别高达0.99和0.95,比PC的分别高出了27%和46%;以PC和PALC标准养护28d时的抗压强度为基准,PC的抗压强度的下降率分别为14.0%,24.2%,PALC的抗压强度下降率则仅为8.6%,14.5%。在腐蚀龄期为360,510d时,对比腐蚀前后水泥砂浆试样的弹性模量,PLAC砂浆的弹性模量的下降率仅为2.42%和7.79%,PC的则达到了22.48%和24.17%。PALC的水化产物中不含有Ca(OH)2和钙钒石,其水化产物主要是羟基磷灰石、水化磷铝酸盐凝胶及水化磷酸盐凝胶。由于水化产物中同时存在的水化磷铝酸盐凝胶及水化磷酸盐凝胶之间可以纵横交联形成致密的网络结构,改进PALC的物理性能,有效地阻止外界离子的侵入,因此,PALC具有更好的耐硫酸盐侵蚀性能。
Abstract：The sulfate attack resistance of phosphoaluminate cement (PALC) was studied. It was compared with Portland cement (PC) pastes and the improvement of the microstructure of cement pastes was proven by means of X-ray diffraction and nuclear magnetic resonance. The results show that PALC has better mechanical capability and sulfate resistance; after being exposed to a solution of MgSO4 at 360 d and 510 d, the corrosion resistance coefficients of PALC mortars are as high as 0.99 and 0.95 respectively. This is 27% and 44% higher than that of PC at the same exposure age. Based on the compressive strength of PC and PALC at 28 d, the compressive strength of PC can be decreased by 14.0% and 24.2%, but the compressive strength of PALC can be decreased by only 8.6% and 14.5%. For 360 d and 510 d exposure, compared with the elastic modulus of cement mortar before and after exposure in the solution of MgSO4, the elastic modulus of PALC is decreased by 2.42% and 7.79%, but the elastic modulus of PC is decreased by 22.48% and 24.17%. The Ca(OH)2 and ettringite are not contained in the hydration products of PALC; its hydration products are hydroxyapatite, the gel hydrates of phosphoaluminate and the gel hydrates of phosphate. These gels form a network structure, improve the physical capability of PALC, and stop the invasion of ions from outside; therefore, PALC mortar has better sulfate resistance.
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基本信息:
中图分类号:TQ172.1
引用信息:
[1]王伟,衣朝华,李仕群,等.新型磷铝酸盐水泥抗硫酸盐侵蚀性能[J].硅酸盐学报,2008,No.225(01):82-87.
基金信息:
国家自然科学基金(50572035);; 深圳大学深圳市土木工程耐久性重点实验室开放基金(CED07–05)资助项目。
2008-01-15
2008-01-15