粉煤灰掺量对水工混凝土早龄期力学性能的影响

The influence of fly ash quantity on early-age mechanical properties of hydraulic concrete

为探究粉煤灰掺量对塔里木灌区水工混凝土早龄期力学性能的影响,本文对不同粉煤灰掺量(0%、10%、20%、30%、40%)混凝土在3、7、28 d龄期的基本力学性能进行宏观和微观的对比试验。结果表明:(1)掺入一定量的粉煤灰可以改善早龄期混凝土的力学性能,且早龄期混凝土强度均随粉煤灰掺量的增加呈现先增长后降低的变化趋势;(2)粉煤灰掺量为10%时,试件立方体抗压强度、劈裂抗拉强度和抗折强度均达到最大值,与基准组试件的相应强度相比,分别提高18.19%、20.13%、17.75%;(3)掺入适量的粉煤灰可以改善材料内部的微观结构,提高材料的密实度。本文研究结果可为粉煤灰在塔里木灌区水工混凝土工程中的广泛应用提供科学依据。

In order to explore the influence of fly ash replacement on earlyage mechanical properties of hydraulic concrete in Tarim irrigation area,the macro and micro comparative tests of basic mechanical properties of concrete with different fly ash replacement(0%,10%,20%,30%,40%)at 3,7,28 d ages were conducted in the paper.The results show that:(1)adding a certain amount of fly ash can improve the mechanical properties of earlyage concrete,and the strength of earlyage concrete increases firstly and then decreases with the increase of fly ash content;(2)When the fly ash content is 10%,the cube compressive strength,splitting tensile strength and flexural strength of the specimen reach their maximum values,which are 18.19%,20.13%,17.75% higher than those of the reference group,respectively;(3)Adding appropriate amount of fly ash can improve the internal microstructure of concrete and enhance the compactness of the material.The research results can provide scientific basis for the wide application of fly ash in hydraulic concrete engineering in Tarim irrigation area.