基于聲發(fā)射技術(shù)的UHPC-NC組合梁延性研究

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ZHENG Yongfei’，LIU Changzhen2，XIE Lu’，GUO Pan4，DENG Enfeng3 （1. CCCC Fourth Highway First Engineering Co.，Ltd.，Beijing 100123， China； 2.CCCC Construction Group Co.，Ltd. ，Beijing 10OO00，China； 3. School of Civil Engineering， Zhengzhou University， Zhengzhou 45OOOO China；

4. Collage of Water Conservancy and Transportation， Zhengzhou University， Zhengzhou 45Oooo China） Abstract：Thedetectionmethodsfortheductilityof UHPC-NCcompositebeamsarerelativelysingular，andeffective monitoring techniques forcrack damage inthe beamsarelacking.This paper conducts four-point bending tests on both NC beamsand UHPC-NCcomposite beams，employing acoustic emission technologyto monitorthe failure processand performing ductlity analysis basedonthecumulativeringing count and energyofacousticemissons.Theresults indicatethat，compared to NC beams，the UHPC-NC composite beam with a 50mm thick UHPC layer exhibits improvements in cracking load，yield load， and ultimate load，with the greatest enhancement observed in the cracking load，which increased by 100% ．However，the displacement ductility and curvature ductility decreased by 7.0% and 10.0% ，respectively. Additionally，during the bending failure process， the UHPC-NC composite beam extended the cracking load phase of the NC beam from 14.0% to 25.0% of theultimateload.Throughtheanalysisofcumulativeringingcountandenergyfromacousticemissions，thisstudydemonstratesthe feasibility of this method for calculating the ductility index of concrete structures.

Keywords：UHPC-NCcombination beam；concrete beam；bending test；ductility；acousticemision；parameter atribute

0 引言

混凝土雖是目前使用最廣泛的建筑材料，但是也存在抗拉強(qiáng)度比較低，幾乎沒有任何延性等問題。（剩余7595字）