THE STRENGTH OF ANCHOR BARS: A REEVALUATION OF TEST DATA ON DEVELOPMENT LENGTH AND SPLICES
THE STRENGTH OF ANCHOR BARS: A REEVALUATION OF TEST DATA ON DEVELOPMENT LENGTH AND SPLICES
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DOI：
10.14359/10993
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发表时间：
1977-03
期刊：
影响因子：
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通讯作者：
C. O. Orangun;J. Jirsa;J. Breen
中科院分区：
文献类型：
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作者：
C. O. Orangun;J. Jirsa;J. Breen
通过对带搭接接头的梁的测试结果进行非线性回归分析，开发了一个方程，用于计算变形钢筋的搭接接头长度。它反映了长度、保护层、间距、钢筋直径、混凝土强度、横向钢筋和弯矩梯度对搭接接头强度的影响。该方程也适用于确定基本开发长度。根据所建立的方程，提出了开发长度和搭接接头的设计建议，并与 1974 年 AASHTO 桥梁临时规范进行了比较。比较表明，对于最不利的接头条件（侧面或底部有 1-1/2 英寸的透明覆盖物、没有横向钢筋的接头、所有钢筋在最大力矩区域进行拼接、中心钢筋间距小于 6 英寸），AASHTO 规定高估了#6 钢筋搭接长度增加 11%，#8 钢筋搭接长度增加 16%，#11 钢筋搭接长度增加 25%。如果保护层增加至 3 英寸或添加横向钢筋，则大钢筋的拼接长度可比现行 AASHTO 规定要求的长度减少多达 60%。此外，控制开发长度的方程基本上与剪接长度的方程相同。 /联邦公路局/
An equation has been developed for calculating lengths of lap splices of deformed bars from a nonlinear regression analysis of test results of beams with lap splices. It reflects the effect of length, cover, spacing, bar diameter, concrete strength, transvers reinforcement, and moment gradient on the strength of lap splices. The equation is also applicable in determining basic development lengths. Based on the equation developed, design recommendations are proposed for development lengths and lap splices and compared with AASHTO Interim Specifications for Bridges, 1974. The comparison shows that for the most unfavorable splice conditions (a clear cover of 1-1/2 in. on sides or bottom, splices with no transverse reinforcement, all bars spliced in a region of maximum moment, and bar spacing less than 6 in. on centers) AASHTO provisions overestimate lap lengths by 11 percent for #6, 16 percent for #8, and 25 percent for #11 bars. If cover is increased to 3 in. or transverse reinforcement is added, the splice length of large bars may be reduced by as much as 60 percent over that required by present AASHTO provisions. Furthermore, the equations governing development length are essentially the same as those for splice length. /FHWA/