PVA纤维增强粉煤灰混凝土的力学性能及耐久性分析  

Analysis of mechanical and durability properties of PVA fiber reinforced fly ash concrete

作　　者：吕大为 LYU Dawei(School of Civil and Transportation Engineering,Henan University of Urban Construction,Pingdingshan 467036,China)

机构地区：[1]河南城建学院土木与交通工程学院,河南平顶山467036

出　　处：《功能材料》2025年第2期2201-2207,2213,共8页Journal of Functional Materials

基　　金：国家自然科学联合基金项目(U1504508)。

摘　　要：以硅烷偶联剂KH-550对聚乙烯醇(PVA)纤维进行表面改性处理,研究了KH-550用量对PVA纤维微观形貌、光谱性能和水接触角的影响,并以改性后的PVA纤维作为添加材料,研究了不同V(去离子水)∶V(KH-550)对PVA纤维增强粉煤灰混凝土的力学性能和耐久性能的影响。结果表明,随着KH-550体积比的增大,PVA纤维表面变得更加粗糙,PVA纤维由疏水状态转变为较为亲水的状态。当V(去离子水)∶V(KH-550)=3∶3时,PVA纤维的水接触角降至最低65.2°。经过KH-550改性处理后,PVA纤维增强粉煤灰混凝土的界面过渡区结合更加紧密,孔隙和裂缝的数量减少,抗压强度和抗折强度得到提高。当V(去离子水)∶V(KH-550)=3∶3时,粉煤灰混凝土的抗压强度和抗折强度达到最大值,分别为44.05和8.70 MPa,相比未处理的混凝土分别提高了67.62%和61.11%。在28 d龄期,当V(去离子水)∶V(KH-550)=3∶3时,粉煤灰混凝土的最大载荷为194.3 N,最大位移为7.3 mm,最低氯离子扩散系数为1.21×10^(-8)cm^(2)/s,具有优异的耐久性能。The surface modification of polyvinyl alcohol(PVA)fibers was carried out using silane coupling agent KH-550.The effect of KH-550 dosage on the microstructure,spectral properties,and water contact angle of PVA fibers were studied.The modified PVA fibers were used as additives to investigate the effects of different V(deionized water):V(KH-550)on the mechanical properties and durability of PVA fiber-reinforced fly ash concrete.The results showed that as the volume ratio of KH-550 increased,the surface of PVA fibers became rougher,and the PVA fibers transitioned from a hydrophobic state to a more hydrophilic state.When V(deionized water)∶V(KH-550)=3∶3,the water contact angle of PVA fibers decreased to a minimum of 65.2°.After KH-550 modification treatment,the interface transition zone of PVA fiber reinforced fly ash concrete was more tightly bonded,the number of pores and cracks was reduced,and the compressive strength and flexural strength were improved.When V(deionized water)∶V(KH-550)=3∶3,the compressive strength and flexural strength of fly ash concrete reached their maximum values of 44.05 and 8.70 MPa,respectively,which were 67.62%and 61.11%higher than untreated concrete.At the age of 28 d,when V(deionized water)∶V(KH-550)=3∶3,the maximum load of fly ash concrete was 194.3 N,the maximum displacement was 7.3 mm,and the minimum chloride ion diffusion coefficient was 1.21×10^(-8)cm^(2)/s,demonstrating excellent durability performance.

关 键 词：粉煤灰混凝土 PVA纤维 KH-550 力学性能 耐久性能 

分 类 号：TU560.25[建筑科学—建筑技术科学]