SiO_(2)-PVA纤维复合改性再生混凝土力学性能  

Mechanical Properties of SiO_(2)-PVA Fiber Composite Reinforced Recycled Concrete

作　　者：肖湘 龙泓屹[1] 唐润东 XIAO Xiang;LONG Hong-yi;TANG Run-dong(School of Civil and Architectural Engineering,Guangxi University,Nanning 530000,China;School of Civil and Architectural Engineering,Nanning University,Nanning 530000,China)

机构地区：[1]广西大学土木建筑工程学院,南宁530000 [2]南宁学院土木与建筑工程学院,南宁530000

出　　处：《科学技术与工程》2025年第2期753-762,共10页Science Technology and Engineering

基　　金：国家自然科学基金(52078370);广西自然科学基金青年科学基金(2023GXNSFBA026135)。

摘　　要：随着复合材料理念的发展,为进一步探究纳米SiO_(2)(Nano-SiO_(2),NS)改性再生粗骨料与聚乙烯醇纤维(polyvinyl alcohol,PVA)耦合作用下复合改性再生混凝土力学性能,开展了坍落度、立方体抗压、轴心抗压、劈裂抗拉和抗折试验,研究了不同取代率下改性再生粗骨料混凝土随聚PVA纤维掺量增加的工作性能和力学性能变化规律。结果表明:随着纤维体积掺量增加,混凝土坍落度增大;混凝土破坏呈脆性,掺纤维的再生混凝土的破坏形态整体性更好;纤维体积掺量为0.05 vol%和0.10 vol%时,不同再生取代率下的立方体抗压强度、极限承载力、劈裂抗拉强度、抗折强度和静弹性模量都会有所减小,但在纤维体积掺量为0.15 vol%时,所有强度会反而超过且提高;PVA纤维会减小抗压极限承载力,对峰值应变出现不同正负效果,建议添加PVA纤维体积掺量为0.1vol%,如需添加PVA纤维,建议在再生取代率低于30 wt%使用。另外发现,改性再生粗骨料性能良好,可有效替代天然骨料或与天然骨料混合在实际工程中使用。With the development of the concept of composite materials,in order to further explore the mechanical properties of composite modified recycled concrete under the coupling effect of NS(nano-SiO_(2))modified recycled coarse aggregate and PVA(polyvinyl alcohol)fibers,slump,cubic compression,axial compression,splitting tensile and flexural tests were carried out to study the working performance and mechanical performance changes of modified recycled coarse aggregate concrete with increasing PVA fiber content under different substitution rates.The results show that the slump of concrete increases with the increase of fiber volume.The damage of concrete is brittle,and the damage pattern of recycled concrete mixed with fiber is better.When the fiber volume content is 0.05 vol%and 0.10 vol%,the cubic compressive strength,ultimate bearing capacity,splitting tensile strength,folding strength and static elastic modulus will decrease under different regeneration and replacement rates,but all the strengths will exceed and increase when the fiber volume content is 0.15 vol%.PVA fiber will reduce the ultimate compressive bearing capacity and have different positive and negative effects on the peak strain.It is recommended to add PVA fiber with a volume content of 0.1 vol%.If PVA fiber is needed,it is recommended to use it when the regeneration and replacement rate is less than 30 wt%.In addition,it is found that the modified reclaimed coarse aggregate has good performance and can effectively replace natural aggregate or be mixed with natural aggregate in practical engineering.

关 键 词：再生混凝土 纳米SiO_(2) PVA纤维 工作性能 力学性能 复合改性 

分 类 号：TU528.041[建筑科学—建筑技术科学]