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周  威^1,2，張格明¹，鄭文忠¹，  劉  鐵¹
（1 哈爾濱工業(yè)大學(xué)土木工程學(xué)院； 2 哈爾濱工業(yè)大學(xué)材料科學(xué)與工程學(xué)院，哈爾濱150090）

[摘要]  某綜合樓層2頂無(wú)粘結(jié)預(yù)應(yīng)力混凝土雙向板在張拉預(yù)應(yīng)力筋時(shí)，發(fā)生了局部區(qū)域混凝土掀起的施工質(zhì)量事故，分析表明是由張拉時(shí)該區(qū)域板混凝土實(shí)際強(qiáng)度過(guò)低所致。采用了放松板中被掀起區(qū)無(wú)粘結(jié)筋、鑿除松動(dòng)混凝土面層、重新澆筑較設(shè)計(jì)強(qiáng)度等級(jí)高一級(jí)的混凝土、再重新張拉無(wú)粘結(jié)筋加固處理方法。利用施工現(xiàn)場(chǎng)實(shí)際條件對(duì)加固后的無(wú)粘結(jié)預(yù)應(yīng)力板進(jìn)行了荷載試驗(yàn)，取得了板撓度實(shí)測(cè)結(jié)果。應(yīng)用雙向板帶疊加法取得了變形的理論計(jì)算值，實(shí)測(cè)值與理論值吻合良好。加固后的預(yù)應(yīng)力板滿足相關(guān)標(biāo)準(zhǔn)中正常使用和承載能力極限狀態(tài)要求，可驗(yàn)收使用。
[關(guān)鍵詞]  無(wú)粘結(jié)；預(yù)應(yīng)力；樓板；混凝土掀起；加固；檢測(cè)

Detecting analysis and treatment of unbonded prestressed concrete slab with raising concrete region
Zhou Wei^1,2, Zhang Geming¹, Zheng Wenzhong¹, Liu Tie¹
(l School of Civil Engineering, Harbin Institute of Technology; 2 School of Material and Engineering, Harbin Institute of Technology, Harbin 150090, China)
   
Abstract: During tensioning unbonded tendons in construction, partially region of concrete was raising on a prestressed concrete two-way slab of a complex building. It is result of low strength concrete in this region.  Reinforcement method is that prestressing tendons were released in rainsing region, cracked concrete was taken out, higher strength concrete than design strength was renewing, moreover, released tendons were tensioned again. To inspect result of reinforcement, loading experiment was carried out on this unbonded prestressed concrete slab using material of practical construction scene. Actual deflections of testing center-span of this slab were measured under external load. Theoretic deflection of center-span was calculated by using method of two-way plane band splicing.  Calculation values are well accorded with test result. Two limits of load-bearing capacity and service of this slab after reirforcement meet with relative standard. So, it can be checked and accepted.
Keywords: unbonded; prestressed; slab; raising concrete: reinforcement; detecting