弱碱激发条件下磷渣-水泥复合填料路用性能试验研究

摘要/Abstract

摘要： 将磷渣固化后作为路基或路面基层填料是固体废弃物资源化利用的有效途径,具有广泛的经济效益和社会价值。本文通过室内和现场试验,从强度和水稳性的角度分析了磷渣-水泥复合填料的路用性能,并通过具体工程案例论证了本文固化方案的可行性。试验结果表明,弱碱激发(pH=8.0)条件下磷渣混合料在压实、固化后可作为路基填料使用,但固化体强度形成较为缓慢,7 d抗压强度约为28 d的50%。经固化后的磷渣-水泥复合填料具备了一定的耐水性,水泥熟料掺量大于7%(质量分数)时,浸泡60 d后未出现影响完整性的破坏,固化体试样的软化系数随着水泥掺量的增加而下降。在保证强度的基础上,固化剂(Na₂SiO₃)的使用可以减少水泥用量,提高磷渣固化方案的经济性;而过度碱激发(pH=10.0)虽然可以提高磷渣固化体的早期强度,但对28 d强度影响并不显著。现场的工程实践表明,本文提出的弱碱激发磷渣固化方法可以有效实现磷渣的资源化再利用,在公路路基和路面基层填筑工程中具有很强的可推广性。

关键词: 磷渣(磷石膏), 固体废弃物, 碱激发, 水泥固化, 水稳性, 路基填料, 路面基层材料

Abstract: Taking solidified phosphorus slag as filler for roadbed or pavement base is an effective way to utilize solid waste resources, which has wildly economic benefits and social value. In this paper, the road performance of phosphorus slag-cement composite filler was analyzed in terms of strength and water durability through laboratory and on-site tests. Then, the availability of the solidification method was discussed through specific engineering cases. The test results indicate that under weak alkali activation (pH=8.0), the compacted phosphorus slag mixture can form a solidified body, whose strength could meet the requirements of roadbed filler. However, strength incensement of solidified body is relatively slow. The compressive strength of solidified body after 7 d is about 50% of the compressive strength after 28 d. The solidified phosphorus slag-cement composite filler is water resistance. Once the cement clinker content is greater than 7% (mass fraction), the damage that affects the integrity of the sample cannot be observed during a 60 dfree soaking, and the softening coefficient of the solidified sample decreases as the content of cement increases. Moreover, keeping the strength as a constant, using curing agent (Na₂SiO₃) can save the amount of cement used and improve the economic efficiency of solidification method. Excessive alkali activation (pH=10.0) can only improve the early strength of solidified body and has little effect on the 28 d strength. Finally, the on-site engineering practice shows that the weak alkali-activated phosphorus slag solidification method can effectively reuse of phosphorus slag resource, which has strong generalizability in highway roadbed and pavement base filling engineering.

Key words: phosphorus slag (phosphogypsum), solid waste, alkali activation, cement solidification, water durability, roadbed filler, pavement base material

中图分类号:

TU825

殷源, 林康, 曾卫新, 程树范. 弱碱激发条件下磷渣-水泥复合填料路用性能试验研究[J]. 硅酸盐通报, 2024, 43(7): 2602-2611.

YIN Yuan, LIN Kang, ZENG Weixin, CHENG Shufan. Experimental Study on Road Performance of Weak Alkali-Activated Phosphorus Slag-Cement Composite Filler[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2024, 43(7): 2602-2611.

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