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张兴龙

 

（首都医科大学附属北京中医医院 ，北京 100010)

摘   要 ：为研究高掺量粉煤灰混凝土力学性能，制备了掺 40% 、50% 、60% 、70% 不同比例粉煤灰及钢纤  维 0. 25% 、0. 50% 、0. 75% 、1% （体积分数） 的混凝土试件，并将其置于模拟环境条件中进行试验。通过测试  试件的抗压强度、劈裂抗拉强度 、干燥收缩率及微观结构，分析高掺量粉煤灰混凝土的力学性能。结果表明： 当粉煤灰掺量在 40%~ 50% 时，混凝土抗压强度下降最为明显；当钢纤维体积分数掺量为 1% 时，劈裂抗拉强度  较未掺钢纤维混凝土增长 24. 4% ,  抗折强度达到最大值 6. 2 MPa ,  较原始强度提高了29. 2% ;  混凝土的干燥收  缩率随着粉煤灰掺量的增加呈现出先降低后升高的趋势， 当掺量增加至 70% 时，收缩率较基准混凝土降低了12. 22% ,  同时混凝土的孔隙率略有回升，约为 8% ;  适当比例的粉煤灰和钢纤维掺入能够显著提升混凝土的抗拉强度、抗折强度，并优化其干燥收缩性能和孔隙结构，增强混凝土的力学性和致密性。

关键词：高掺量 ；粉煤灰 ；混凝土 ；钢纤维 ；力学性能

中图分类号：TU528 . 01            

文献标志码：A            

文章编号： 1005- 8249  (2025)  02- 0049- 05

DOI:10. 19860/j.cnki.issn1005 - 8249.2025 .02.009

 

ZHANG Xinglong

(Beijing Hospital of Traditional Chinese Medicine ,  Capital Medical University ,  Beijing 100010 ,  China) 

Abstract: To study the mechanical properties of high content fly ash concrete, concrete specimens containing different proportions of fly ash (40%, 50%, 60%, 70%) and steel fibers (volume fractions of 0.25%, 0.50%, 0.75%, 1.00%) were prepared and tested under simulated environmental conditions. Analyze the mechanical properties of high content fly ash concrete by testing the compressive strength, splitting tensile strength, drying shrinkage rate, and microstructure of the specimens. The results show that the compressive strength of concrete decreases most significantly when the fly ash content is between 40% and 50%; When the volume fraction of steel fibers increases from 0% to 1.00%, the increase in splitting tensile strength reaches 24.4%, and the maximum flexural strength reaches 6.2 MPa, an increase of 29.2% compared to the original strength; The drying shrinkage rate of concrete shows a trend of first decreasing and then increasing with the increase of fly ash content. When the content increases to 70%, the shrinkage rate decreases by 12.22% compared to the benchmark concrete, and the porosity of the concrete slightly increases to about 8%. Based on the above results, it can be concluded that the appropriate proportion of fly ash and steel fibers can significantly improve the tensile strength and flexural strength of concrete, optimize its drying shrinkage performance and pore structure, thereby enhancing the mechanical properties and compactness of  concrete.

Key words: high admixture; fly ash; concrete; steel fiber; mechanical properties

作者简介： 张兴龙  (1981 —) ,  男 ，本科 ，工程师 ，研究方向：建筑工程技术。

收稿日期：2024-10- 09