摘要
为了提高再生微粉在混凝土中的利用率,将单掺再生微粉的混凝土与复掺再生微粉、粉煤灰和硅灰的混凝土的力学性能及微观结构进行了对比研究。结果表明,单掺再生微粉和三者复掺对混凝土的抗压强度和孔结构有不同程度的影响,当掺量低于20%时,单掺再生微粉的混凝土抗压强度高于同掺量时的复掺混凝土,孔隙率相比于复掺时也有所降低;而掺量高于20%时,复掺效果优于单掺,特别是当复掺掺量为30%时,混凝土28 d抗压强度相比单掺掺量为30%时提高了33.4%,总孔隙率和大孔占总孔隙的比例分别降低了4.4%和17.77%。这说明再生微粉的掺入量较大会给混凝土带来不利影响,但添加粉煤灰与硅灰后,它们可以发挥协同作用,从而改善混凝土的复合水泥基体强度和孔结构。
In order to improve the utilization rate of recycled powder in concrete,the mechanical properties and microstructure of single-doped recycled powder concrete and compound recycled powder,fly ash and silica ash concrete were compared.The results show that the single-doped recycled fine powder and the three-way re-mixing have different degrees of influence on the compressive strength and pore structure of the concrete,and when the dosage is less than 20%,the compressive strength of the single-doped recycled fine powder is higher than that of the re-mixed concrete when it was combined,and the porosity was also reduced relative to the re-doping time.When the dosage is higher than 20%,the compounding effect is better than that of single doping,especially when the compounding is 30%,the compressive strength of the concrete in 28 d is increased by 33.4%compared with the single doping by 30%,and the total porosity and the proportion of large pores to total pores are reduced by 4.4%and 17.77%,respectively.This shows that when the amount of recycled powder is incorporated,it will adversely affect the concrete,but after adding fly ash and silica ash,it can play a synergistic effect to improve the composite cement matrix strength and pore structure of the concrete.
作者
陈立俊
李滢
陈文浩
CHEN Lijun;LI Ying;CHEN Wenhao(School of Civil Engineering,Qinghai University,Xining 810016,China;Qinghai Provincial Key Laboratory of Energy Saving Building Materials and Engineering Safety,Xining 810016,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2024年第5期178-183,共6页
Materials Reports
基金
国家自然科学基金(51668052)
青海省科技厅基础研究计划项目(2023-ZJ-725)。
关键词
再生微粉
混凝土
微观结构
力学性能
孔结构
协同作用
recycled powder
concrete
microstructure
mechanical property
pore structure
synergistic effect
