石屑对混凝土工作性及强度的影响试验研究

Experimental Research on the effect of Stone Chips on Workability and Strength of Concrete

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关键词:

石屑;等效砂浆;工作性;混凝土;抗压强度

Key words:

Stone chips; Equivalent mortar; Workability; Concrete; Compressive strength

刊期:

2019年第7期

DOI:

10.19761/j.1000-4637.2019.07.004.05

文章编号:

基金项目:

国家重点研发计划课题(2017YFB0310905-06)。

作者:

赵明亮1,黄 赟2,费洗非3,水中和2,郭 伟3

单位:

1.武汉理工大学材料科学与工程学院,430070;2.武汉理工大学硅酸盐建筑材料国家重点实验室,430070;3.珠海春禾新材料研究院有限公司,519000

摘要

摘   要:针对石屑应用引起的细骨料性质波动,探究了石屑石粉含量、取代海砂比例对混凝土工作性、强度的影响,并提出了混凝土工作性调整的相关建议。结果表明,石粉含量每增加1%,外加剂适宜掺量需增加0.054%;当砂率小于41%时,石屑对混凝土工作性影响可不予考虑,当砂率大于41%时,应控制石屑比例不超过60%;当砂率为43%,石屑比例为40%时,中低强度等级混凝土的和易性、黏聚性达到最佳;混凝土外加剂与等效砂浆外加剂适宜掺量关系为:y=0.88x+0.39,可为细骨料波动下混凝土外加剂调整提供参考。
Abstract:Aiming at the fluctuation of fine aggregate properties caused by the application of stone chips, the influence of the content of stone powder and the proportion of replacing sea sand on the workability and strength of concrete was studied, some suggestions for the adjustment of workability were put forward. The results show that when the content of stone powder increases by 1%, the suitable amount of admixture needs to increase by 0.054%; when the sand ratio is less than 41%, the influence of stone chips has little effect on the workability of concrete; when the sand ratio is more than 41%, the proportion of stone chips should be controlled not to exceed 60%; when the sand ratio is 43%, the proportion of stone chips is 40%, the workability and cohesiveness of medium-low grade concrete are the best; the relationship of suitable amount of admixture between equivalent mortar and concrete is y=0.88x+0.39, which can provide reference for the adjustment of concrete admixture under the fluctuation of fine aggregate.

结论

(1)引气剂掺量及类型对机制砂海工混凝土抗压强度的影响结果表明,当GW醚类引气剂掺量为0.2%~0.3%、ML醚类引气剂掺量为0.2%~0.4%时,机制砂海工混凝土的28 d抗压强度均满足C35强度等级要求,而掺入SX松香引气剂的机制砂海工混凝土未能满足强度等级要求。
(2)不同引气剂掺量及类型对机制砂海工混凝土抗冻性能的影响结果表明,当GW醚类引气剂掺量为0.5%,SX松香引气剂掺量为0.3%,ML醚类引气剂掺量为0.4%时,机制砂海工混凝土均有较好的抗冻性能,且当ML醚类引气剂掺量为0.4%时,机制砂海工混凝土抗冻性能最优;醚类引气剂比松香引气剂可进一步改善混凝土的工作性能,其引入的微小气泡可以改善混凝土的包裹性,同时不影响混凝土的抗压强度。
(3)微观形貌分析结果表明,掺入ML醚类引气剂使机制砂混凝土有较高的强度、较小的气泡间距系数和平均气孔弦长,因此,抗冻性能较好。

参考文献

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引用本文

赵明亮,黄赟,费洗非,等.石屑对混凝土工作性及强度的影响试验研究[J].混凝土与水泥制品,2019(7):4-8.

ZHAO M L,HUANG Y,FEI X F,et al.Experimental Research on the effect of Stone Chips on Workability and Strength of Concrete[J].China Concrete and Cement Products,2019(7):4-8.

 


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