摘要
为探究500℃煅烧纳米凹凸棒土对再生混凝土劈拉、抗折强度的影响,以煅烧NAT掺量及再生骨料取代率作为变量制备纳米再生混凝土并进行劈拉、抗折强度试验,并结合扫描电子显微镜及孔径分析仪研究破坏面微观形貌以及孔径分布特征,以期得出煅烧纳米凹凸棒土对再生混凝土劈拉、抗折强度的影响规律和改善机理.结果表明:煅烧纳米凹凸棒土的掺入对不同再生骨料取代率的再生混凝土劈拉、抗折强度均有改善作用.当再生骨料取代率为30%时,掺入6%煅烧纳米凹凸棒土的再生混凝土劈拉、抗折强度值最大;煅烧纳米凹凸棒土的掺加填充了再生混凝土内部部分大孔、中孔孔隙,降低总孔体积,细化了再生混凝土的孔隙结构,提高了结构的密实度并使得水化反应产生的C-S-H凝胶增加,水化产物之间的连接更为紧密,内部结构中的孔隙和裂缝减少,再生混凝土的劈拉、抗折强度提高.
To explore the influence of nanometer attapulgite(NAT)calcined at 500℃on the splitting tensile and flexural strength of recycled concrete.Nano-recycled concrete was prepared with the content of calcined NAT and the replacement rate of recycled aggregate as variables and splitting tensile and flexural strength tests were carried out,and combined with the scanning electron microscope(SEM)and pore size analyzer,the micro-morphology and pore size distribution characteristics of failure surface were studied,aiming to obtain the influence law and improvement mechanism of calcined NAT on the splitting tensile and flexural strength of recycled concrete.The test results show that the addition of calcined NAT can improve the splitting tensile strength and flexural strength of recycled concrete with different replacement rates of recycled aggregate.When the replacement rate of recycled aggregate is 30%,the splitting tensile and flexural strength of recycled concrete with 6%calcined NAT is the highest;the addition of calcined NAT fills part of the macropores and mesopores in recycled concrete,which reduces the total pore volume,refines the pore structure of recycled concrete,improves the compactness of the structure,and increases the C-S-H gel produced by the hydration reaction,the hydration products are connected more closely,and the pores and cracks in the internal structure are reduced,thus the recycled concrete′s splitting tensile and flexural strength are improved.
作者
阎杰
陆超
柏永清
于旭涛
谢军
王甫丽
刘兴隆
YAN Jie;LU Chao;BAI Yongqing;YU Xutao;XIE Jun;WANG Fuli;LIU Xinglong(School of Civil Engineering,Hebei University of Architecture,Zhangjiakou 075000,China;Hebei University Green Building Materials and Building Transformation Application Technology Researchand Development Center,Zhangjiakou 075000,China)
出处
《江苏科技大学学报（自然科学版）》
CAS
北大核心
2023年第4期111-118,共8页
Journal of Jiangsu University of Science and Technology:Natural Science Edition
基金
河北省自然科学基金资助项目(E2018404047)
河北省高等学校科学研究计划项目(ZD2022066)。
关键词
纳米凹凸棒土
再生混凝土
抗折强度
劈拉强度
nano attapulgite
recycled concrete
flexural strength
splitting tensile strengthn
