首页|粉煤灰掺量对全再生自密实混凝土工作性能与力学性能的影响

粉煤灰掺量对全再生自密实混凝土工作性能与力学性能的影响

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  • 国家科技期刊平台
  • NETL
  • NSTL
  • 万方数据
本文使用再生粗骨料全部替代天然粗骨料,用粉煤灰分别替代20％、30％、40％、50％和70％(质量分数)水泥,制备了不同水胶比(0.36、0.40和0.45)的全再生自密实混凝土,通过抗折强度试验和抗压强度试验,分析了粉煤灰掺量和水胶比对全再生自密实混凝土性能的影响规律,得到了粉煤灰的合理掺量,提出了适用于全再生自密实混凝土抗折强度的计算公式.结果表明:当粉煤灰掺量由20％增至40％时,所有全再生自密实混凝土拌合物的坍落扩展度呈先增加后降低趋势,且均表现出良好的间隙通过能力,但混凝土拌合物扩展时间T500受粉煤灰的影响不显著;随着粉煤灰掺量增加,全再生自密实混凝土的抗压强度和抗折强度均呈先增加后降低趋势,抗折强度受粉煤灰掺量的影响程度要高于抗压强度;全再生自密实混凝土抗压强度和抗折强度受水胶比的影响程度相同;综合粉煤灰掺量对全再生自密实混凝土工作性能和力学性能的影响,建议粉煤灰对水泥的取代率为30％.
Effect of Fly Ash Content on Workability and Mechanical Properties of Fully Recycled Self-Compacting Concrete
In this paper,recycled coarse aggregate was used to replace natural coarse aggregate,and fly ash was used to replace 20％,30％,40％,50％and 70％(mass fraction)of cement,respectively.The full recycled self-compacting concrete with different water-binder ratios(0.36,0.40 and 0.45)was prepared.Through flexural strength and compressive strength tests,the effects of fly ash content and water-binder ratio on the performance of full recycled self-compacting concrete were analyzed.The reasonable content of fly ash was obtained,and the calculation formula suitable for flexural strength of full recycled self-compacting concrete was proposed.The results show that when fly ash content increases from 20％to 40％,the slump expansion of all recycled self-compacting concrete mixtures increases first and then decreases,and all of them show good clearance capacity,but the expansion time T500 of concrete mixture is not significantly affected by fly ash.With the increase of fly ash content,the compressive strength and flexural strength of fully recycled self-compacting concrete increase first and then decrease,and the flexural strength is more affected by fly ash content than compressive strength.The compressive strength and flexural strength of fully recycled self-compacting concrete are affected by water-binder ratio to the same extent.Based on the effect of fly ash content on the workability and mechanical properties of fully recycled self-compacting concrete,it is suggested that the replacement rate of fly ash to cement is 30％.

self-compacting concreterecycled concretefly ash contentworkabilitycompressive strengthflexural strength

郑述芳、李华影、陈祥花、梁莹、陈宗平

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广西农业职业技术大学城乡建设学院,南宁 530007

广西大学土木建筑工程学院,南宁 530000

南宁学院土木与建筑工程学院,南宁 530000

自密实混凝土 再生混凝土 粉煤灰掺量 工作性能 抗压强度 抗折强度

国家自然科学基金中央引导地方科技发展资金项目广西农业科技自筹经费项目广西高校中青年教师科研基础能力提升项目广西大学对口支援学科建设项目

55220105005桂科ZY21195010Z2022322023KY12252023N01

2024

硅酸盐通报
中国硅酸盐学会 中材人工晶体研究院

硅酸盐通报

CSTPCD北大核心
影响因子：0.698
ISSN：1001-1625
年,卷(期)：2024.43(4)
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