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(1 東南大學(xué)土木工程學(xué)院  南京 210096;2 江蘇建華建設(shè)有限公司  南京 210009)

［提要］  對(duì)RC雙向板的加固采用粘貼補(bǔ)強(qiáng)技術(shù)存在諸多施工難點(diǎn)，如混凝土板底的大面積打磨處理、粘膠層涂抹時(shí)的厚度控制、大面積鋼板的安裝就位等等。體外預(yù)應(yīng)力加固技術(shù)則不存在上述問(wèn)題，它不僅施工方便，而且可以主動(dòng)消除新加部分的應(yīng)力滯后。通過(guò)5塊RC簡(jiǎn)支雙向板的單向體外預(yù)應(yīng)力加固試驗(yàn)，研究了預(yù)應(yīng)力鋼筋的張拉控制力及其布筋形式對(duì)雙向板受力性能的影響。試驗(yàn)結(jié)果表明，體外預(yù)應(yīng)力可有效地改善雙向板的受力性能，提高雙向板的極限承載能力，在雙向板的跨中區(qū)段“集中布置”體外預(yù)應(yīng)力鋼筋加固效果最佳。

［關(guān)鍵詞］  體外預(yù)應(yīng)力  加固  混凝土  雙向板  承載力

Experimental Study on RC Two way Slabs Strengthened by One way External Prestressing/Wu Yuan1，Hu Cheng1，Cao Shuangyin1，Li Yanhe2 (1 College of Civil Engineering，Southeast University，Nanjing 210096，China； 2 Jiangsu Jianhua Construction Co.，Ltd.，Nanjing 210009，China)

Abstract:At present, applications and studies on strengthened RC two way slabs are mostly based on external bonding method. However, this kind of method has many problems in construction, such as a great deal roughening work, the thickness control of adhesive layer and inconvenience of construction for large plates etc., all such difficulties obstruct its application in practice. While, external prestressing method has not these problems,and it is not only ease of construction, but also can avoid stress lag. Therefore, based on the tests of five pieces of simply supported two way slabs strengthened by one way external prestressing, the effects of different initial stresses and layouts of tendons on the behaviours of slabs were studied. Experimental results showed that external prestressing improved the behaviours of two way slabs greatly, increased the ultimate bearing capacity of slabs, and the layout with dense tendons in the midst of slab was more efficient.

Keywords:external prestressing; strengthening; two way slabs; bearing capacity