Abstract: The tensile capacity of concrete is usually neglected when calculating the strength of a reinforced concrete beam or slab, even though concrete continues to carry tensile stress between the cracks due to the transfer of forces from the tensile reinforcement to the concrete through bond. This contribution of the tensile concrete is known as tension stiffening and it affects the member’s stiffness after cracking and hence the deflection of the member and the width of the cracks under service loads. For lightly reinforced members, such as floor slabs, the flexural stiffness of a fully cracked section is many times smaller than that of an uncracked section, and tension stiffening contributes greatly to the postcracking stiffness. In this paper, the approaches to account for tension stiffening in the ACI, European, and British codes are eva luated critically and predictions are compared with experimental observations. Finally, recommendations are included for modeling tension stiffening in the design of reinforced concrete floor slabs for deflection control.
DOI: 10.1061/（ASCE）0733-9445（2007）133:6（899）
摘要：當(dāng)計(jì)算一個(gè)鋼筋混凝土梁或板的承載力時(shí)混凝土的抗拉能力通常被忽視,盡管具體的拉應(yīng)力繼續(xù)進(jìn)行，由于拉鋼筋到混凝土之間裂縫的轉(zhuǎn)換力量。這一種混凝土的拉力被稱(chēng)為混凝土的張力硬化。在開(kāi)裂后它會(huì)影響鋼筋混凝土的剛度，因此它的撓度和裂縫寬度必須根據(jù)屈服強(qiáng)度負(fù)載。對(duì)輕混凝土，例如樓板，全部裂縫的彎曲剛度比沒(méi)有裂縫部分的要小很多，張力加勁有助于剛度。在本文中，ACI方法必須考慮到緊張加勁，歐洲和英國(guó)的方法是嚴(yán)格評(píng)估和預(yù)測(cè)與實(shí)驗(yàn)結(jié)果進(jìn)行比較。最后，建議書(shū)包括建模系統(tǒng)緊張撓度控制的鋼筋混凝土樓板設(shè)計(jì)變硬。
分類(lèi)號(hào)： 1061/ASCE0733-94452007133:6899
關(guān)鍵詞：開(kāi)裂;蠕變撓度，混凝土，鋼筋，適用性，收縮，混凝土磚。