PVA-FRCCs粘贴式薄板单轴直接拉伸试验研究  

Uniaxial direct tensile test study of PVA-FRCCs by bended thin sheet

作　　者：高淑玲[1,2] 刘波[1] 袁全[1] 陈培[1] 

机构地区：[1]河北工业大学土木工程学院,天津300401 [2]河北省土木工程技术研究中心,天津300401

出　　处：《东南大学学报（自然科学版）》2010年第A02期113-118,共6页Journal of Southeast University：Natural Science Edition

基　　金：中国博士后科学基金资助项目(20100470046);江苏省土木工程材料重点实验室开放基金资助项目;国家重点基础研究发展计划(973计划)资助项目(2009CB623203);河北省建设科技资助项目(2009-258)

摘　　要：为了研究切口大小、水泥标号、粉煤灰掺量对聚乙烯醇纤维增强水泥基复合材料(简称PVA-FRCCs)拉伸力学特性的影响,采用矩形薄板试件,在试件端部用环氧树脂贴一层碳纤维布或者玻璃纤维布,然后粘贴上楔形钢板进行端部加固避免应力集中破坏;采用MTS疲劳试验机控制系统,利用等速位移控制,得到了稳定的拉伸应力-应变全曲线.通过比较切口和无切口直接拉伸试件在起裂荷载、峰值荷载及其对应的应变差异发现:切口较小时,差异不大,但切口较大时,起裂荷载和峰值荷载都降低,起裂荷载对应的应变变化不大,但峰值荷载对应的拉应变和抗拉韧性值A都增加.说明两边有较小切口时反而有利于多条裂缝开展,小切口并不影响裂缝的开裂形态,起始裂缝发生的位置和无切口试件相同,一般不出现在切口处,但当切口长度较大时,裂缝开裂形态受开口影响较大,起始裂缝一般出现在切口处.In order to study the influence of notch size,cement grade and fly ash amount on tensile mechanical characteristics of polyvinyl alcohol fiber reinforced cementitious composites（PVA-FRCCs）,the carbon fiber cloth or glass fiber cloth is glued on the end surface of rectangular thin sheet specimen by epoxy resin,and then wedge-shaped steel plate is glued to avoid damage due to stress concentration.The MTS fatigue tester control system is used to obtain the stable tensile stress-strain full curves by using constant displacement control.Through comparing the differences of the initial crack load,the peak load and their corresponding strain between double-notched and unnotched specimens,it is found that there are very little differences with short notch.But,with longer notch,although the initial crack load and the peak load are both decreased,the strains corresponding initial crack load almost do not change.The tensile strains corresponding the peak load and tensile toughness values A increase.This shows that short double notches in the specimens benefit to multiple crack developing.In addition,short notches do not affect the cracking form.The location of initial crack is not at the notch tip but the same to the unnotched specimens.When notch length is longer,crack developments are greatly influenced and the initial crack usually occurs at the notch.

关 键 词：聚乙烯醇纤维增强水泥基复合材料(PVA-FRCCs) 粘贴式薄板单轴直接拉伸 MTS疲劳试验机 两边切口 

分 类 号：TU528[建筑科学—建筑技术科学]