复合降碱改性生态多孔混凝土抗硫酸盐侵蚀性能研究

doi:10.16552/j.cnki.issn1001-1625.2025.1298

摘要/Abstract

摘要：

为提升生态多孔混凝土（EPC）在硫酸盐-干湿循环环境下的服役耐久性，采用硅藻土（DE）、草酸（OA）和硫酸铁（FS）构建复合降碱体系，制备了不同碱度梯度的EPC试件，系统研究了其在硫酸盐-干湿循环作用下的宏观性能演化及微观结构变化规律。通过相对抗压强度和质量损失率表征EPC的宏观劣化行为，并借助XRD、FTIR和SEM分析其水化产物与微观结构特征。结果表明，适度降碱可显著提升EPC的抗硫酸盐侵蚀性能，其中OA-FS复合体系掺量为1.2%（质量分数）的组（pH=9.0~10.0）在经历24次硫酸盐-干湿循环后仍保持最高的相对抗压强度（72.59%）。微观表征显示，DE-OA-FS复合体系通过促进C-S-H凝胶生成与结构稳定化、减缓Ca（OH）₂的快速消耗并抑制钙矾石（AFt）等侵蚀产物的集中析出，优化了EPC孔结构与化学稳定性，从而延缓了裂纹扩展与碳化劣化进程。研究结果可为EPC在复杂侵蚀环境下的耐久性优化设计与工程应用提供技术参考。

关键词: 生态多孔混凝土, 硫酸盐-干湿循环, 碱度梯度, 宏观力学性能, 微观结构

Abstract:

In order to improve the service durability of ecological porous concrete （EPC） in a sulfate dry-wet cycling environment， a composite alkali-reduction system was established using diatomaceous earth （DE）， oxalic acid （OA） and ferric sulfate （FS）. EPC specimens with different alkalinity gradients were prepared， and the evolution of macroscopic property and the variation of microstructure under sulfate dry-wet cycles were systematically investigated. The macroscopic deterioration behavior of EPC was characterized by relative compressive strength and mass loss rate， while hydration products and microstructural features were analyzed by XRD， FTIR， and SEM. The results show that moderate alkali reduction significantly improves the sulfate erosion resistance of EPC. Among the specimens， the group with 1.2% （mass fraction） OA-FS composite system （pH=9.0 to 10.0） still maintains the highest relative compressive strength （72.59%） after 24 sulfate dry-wet cycles. Microstructural characterization shows that the DE-OA-FS composite system optimizes the pore structure and chemical stability of EPC by promoting the formation and structural stabilization of C-S-H gel， slowing the rapid consumption of Ca（OH）₂， and inhibiting the concentrated precipitation of sulfate-attack products such as ettringite （AFt）， thereby delaying the process of crack propagation and carbonation-induced deterioration. The findings provide a technical reference for durability optimization design and engineering applications of EPC in complex aggressive environments.

Key words: ecological porous concrete, sulfate dry-wet cycle, alkalinity gradient, macroscopic mechanical property, microstructure

中图分类号:

TU528

欧阳琦, 尹健, 李思娇, 陈怡豪, 覃宇航, 曾一. 复合降碱改性生态多孔混凝土抗硫酸盐侵蚀性能研究[J]. 硅酸盐通报, 2026, 45(7): 2290-2298.

OUYANG Qi, YIN Jian, LI Sijiao, CHEN Yihao, QIN Yuhang, ZENG Yi. Sulfate Erosion Resistance of Composite Alkali-Reducing Modified Ecological Porous Concrete[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2026, 45(7): 2290-2298.

图/表 10

表1 水泥和硅藻土的化学组分

Table 1 Chemical composition of OPC and DE

Material	Mass fraction/%
Material	CaO	SiO₂	Al₂O₃	SO₃	Fe₂O₃	MgO	Na₂O
OPC	62.55	21.89	5.58	2.89	2.86	2.26	0.83
DE	—	≥85.00	≤3.35	—	≤1.30	—	—

表2 化学外加剂材料性能

Table 2 Properties of chemical admixtures

Name	Molecular formula	Molecular weight	Standard value	Property
OA	C₂H₂O₄·2H₂O	90.034 9	≥99.5	White crystalline powder
FS	Fe₂（SO₄）₃·7H₂O	399.88	21.0~23.0	Light yellow powder

表3 不同碱度梯度下EPC的配合比及28 d抗压强度

Table 3 Mix ratio of EPC under different alkalinity gradients and compressive strength at 28 d

Sample No.	Mix ratio/（kg·m^-3）								28 d compressive strength/MPa
Sample No.	Alkali gradient	Aggregate	Cement	DE	Water	SP	OA	FS	28 d compressive strength/MPa
B	11.0~12.0	1 533	438	―	110	―	―	―	7.9
A1	10.0~11.0	1 533	443	38.5	120	1.44	2.4	2.4	11.2
A2	9.0~10.0	1 533	443	38.5	120	1.44	6.0	6.0	13.5
A3	8.0~9.0	1 533	443	38.5	120	1.44	9.6	9.6	14.7

图1 在硫酸盐-干湿循环作用下不同碱度梯度下EPC的相对抗压强度

Fig.1 Relative compressive strength of EPC with different alkalinity gradients under sulfate dry-wet cycle action

图2 硫酸盐-干湿循环作用下不同碱度梯度EPC的质量损失率

Fig.2 Mass loss rate of EPC with different alkalinity gradients under sulfate dry-wet cycle action

图3 硫酸盐-干湿循环作用下不同碱度梯度EPC的XRD谱

Fig.3 XRD patterns of EPC with different alkalinity gradients under sulfate dry-wet cycle action

图4 硫酸盐-干湿循环作用下不同碱度梯度EPC的FTIR谱

Fig.4 FTIR spectra of EPC with different alkalinity gradients under sulfate dry-wet cycle action

图5 硫酸盐-干湿循环作用前EPC的SEM照片

Fig.5 SEM images of EPC before sulfate dry-wet cycle action

图6 硫酸盐-干湿循环12次后B组试样的SEM照片

Fig.6 SEM images of group B samples after 12 times of sulfate dry-wet cycle action

图7 硫酸盐-干湿循环24次后A2组试样的SEM照片

Fig.7 SEM images of group A2 samples after 24 times of sulfate dry-wet cycle action

参考文献 21

[1]	FAIZ H， NG S， RAHMAN M. A state-of-the-art review on the advancement of sustainable vegetation concrete in slope stability［J］. Construction and Building Materials， 2022， 326： 126502. DOI URL
[2]	LIU C， XIA Y Y， CHEN J G， et al. Research and application progress of vegetation porous concrete［J］. Materials， 2023， 16（21）： 7039. DOI URL
[3]	TANG W， MOHSENI E， WANG Z Y. Development of vegetation concrete technology for slope protection and greening［J］. Construction and Building Materials， 2018， 179： 605-613. DOI URL
[4]	MOHANTY S， SAHOO K， SAMAL K. Progress in sustainable vegetation eco-concrete technology： a review on materials， applications and challenges［J］. Journal of Building Engineering， 2025， 104： 112354. DOI URL
[5]	SHAO W， XIAO Q Y， ZHANG W B， et al. Numerical modeling of chloride convection-diffusion-reaction in reinforced concrete under external sulfate attack and drying-wetting cycles［J］. Construction and Building Materials， 2025， 472： 140964. DOI URL
[6]	SONG H， FAN S J， ZHANG S L， et al. Strength deterioration prediction of pervious concrete in sulfate and dry-wet cycle environments utilizing ultrasonic velocity［J］. PLoS One， 2023， 18（6）： e0286948.
[7]	桑正辉，尹健，高婷，等. 生态多孔混凝土抗硫酸盐腐蚀性能研究［J］. 铁道科学与工程学报， 2017， 14（9）： 1871-1877.
	SANG Z H， YIN J， GAO T， et al. Study on the anti sulfate corrosion of eco porous concrete［J］. Journal of Railway Science and Engineering， 2017， 14（9）： 1871-1877 （in Chinese）.
[8]	YAN X C， HE Z M， XIA Q， et al. A new type of self-compacting recycled pervious concrete under sulfate drying-wetting exposure［J］. Materials， 2025， 18（3）： 704. DOI URL
[9]	ZHUANG P Y， YAN X J， WANG X H， et al. Study on the performance optimization of plant-growing ecological concrete［J］. Sustainability， 2024， 16（11）： 4575. DOI URL
[10]	YANG C， FANG Y， WEI P C， et al. Optimization study on alkali-reduction techniques and vegetation performance of planting concrete incorporating phosphogypsum［J］. Construction and Building Materials， 2025， 482： 141663. DOI URL
[11]	GANAPATHY G P， ALAGU A， RAMACHANDRAN S， et al. Effects of fly ash and silica fume on alkalinity， strength and planting characteristics of vegetation porous concrete［J］. Journal of Materials Research and Technology， 2023， 24： 5347-5360. DOI URL
[12]	NIVEDITHA M， PALANISAMY T. Oxalic acid optimization for iron-based solid waste conversion into a carbon-sequestering composite building material［J］. Sustainable Chemistry and Pharmacy， 2025， 43： 101875. DOI URL
[13]	LI S J， YIN J， LIU J， et al. Synergistic effects of diatomaceous earth， oxalic acid and ferric sulfate on ecological porous concrete： mechanisms of alkalinity reduction and enhancement［J］. Case Studies in Construction Materials， 2025， 22： e04697.
[14]	LI S J， YIN J， XU W X， et al. Alkalinity regulation and optimization of cementitious materials used in ecological porous concrete［J］. Materials， 2024， 17（8）： 1918. DOI URL
[15]	ZHU Y Y， YIN J， LI S J， et al. Early-strength mechanisms， carbon sequestration， and phytocompatibility of ecological porous concrete synergistically modified with triethanolamine and nano-silica： hydration kinetics and microstructural mechanisms［J］. Journal of Building Engineering， 2025， 107： 112669. DOI URL
[16]	中华人民共和国住房和城乡建设部，国家市场监督管理总局. 混凝土长期性能和耐久性能试验方法标准：［S］. 北京：中国建筑工业出版社， 2024.
	Ministry of Housing and Uran-Rural Development of the People， Republie of China. Standard for test methods of long-term performance and durability of ordinary concrete：［S］. Beiing： China Architecture & Building Press， 2024 （in Chinese）.
[17]	HAMADA H M， ABDULHALEEM K N， MAJDI A， et al. The durability of concrete produced from pozzolan materials as a partially cement replacement： a comprehensive review［J］. Materials Today： Proceedings， 2023， 83： 2040-2046.
[18]	ZHANG H R， HE B J， ZHAO B J， et al. Using diatomite as a partial replacement of cement for improving the performance of recycled aggregate concrete （RAC）-effects and mechanism［J］. Construction and Building Materials， 2023， 385： 131518. DOI URL
[19]	ZHANG G Z， WU C， HOU D S， et al. Effect of environmental pH values on phase composition and microstructure of Portland cement paste under sulfate attack［J］. Composites Part B： Engineering， 2021， 216： 108862.
[20]	HUANG T H， LI B， ZHANG Z Z， et al. A novel oxalic acid activated calcium silicate cement： strength， microstructure and composition evolution［J］. Cement and Concrete Composites， 2026， 165： 106344. DOI URL
[21]	WAN D W， ZHANG W Q， TAO Y， et al. The impact of Fe dosage on the ettringite formation during high ferrite cement hydration［J］. Journal of the American Ceramic Society， 2021， 104（7）： 3652-3664. DOI URL