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（1 天津城建大學(xué)土木工程學(xué)院， 天津 300384； 2 天津大學(xué)土木工程學(xué)院， 天津 300072）

［摘要］采取室內(nèi)試驗(yàn)與有限元分析相結(jié)合的手段，研究早齡期張拉預(yù)應(yīng)力是否可以降低混凝土梁的徐變值。室內(nèi)試驗(yàn)部分以實(shí)際工程為依托，制作了4根1∶6的縮尺試件。設(shè)計(jì)了兩種不同的預(yù)應(yīng)力張拉方案，通過比較不同方案中預(yù)應(yīng)力筋的預(yù)應(yīng)力損失、梁的撓度、梁截面混凝土的應(yīng)變、梁截面曲率等方面的試驗(yàn)數(shù)值，可以看出在早齡期進(jìn)行張拉的兩次張拉方式對(duì)于降低混凝土徐變是最有效的。又利用有限元計(jì)算了兩種張拉方案中預(yù)應(yīng)力混凝土梁的豎向變形，驗(yàn)證了試驗(yàn)的準(zhǔn)確性，并再次證實(shí)了早齡期張拉的施工方法可以明顯地降低預(yù)應(yīng)力混凝土梁的徐變值。

［關(guān)鍵詞］早齡期; 預(yù)應(yīng)力梁; 徐變; 試驗(yàn); 有限元分析

中圖分類號(hào)：TU757.1      文獻(xiàn)標(biāo)識(shí)碼：A      文章編號(hào)：1002-848X(2014)14-0024-04

Research on the influence of pre-stress tensioning on creep of concrete beams at early ages

Xiong Wei1,2, Ding Hongyan2

 (1 School of Civil Engineering, Tianjin Chengjian University, Tianjin 300384, China; 2 School of Civil Engineering,Tianjin University, Tianjin 300072, China)

Abstract: In order to study whether pre-stress tensioning at early ages may reduce the creep value of concrete beams, indoor test and finite element analysis were combined to carry out the research. Indoor test mainly relies on practical engineering project, four 1∶6 micro test specimens were made. Besides, different pre-stress tensioning schemes were designed for the test specimens. By comparing the prestress loss of pre-stress reinforcement, the -deflection of beams, the deformation of beams section concrete, the curvature of beams section and other values in these test schemes, it may be discovered that, the two tensioning modes among tensioning operations at early ages are the most effective approaches to reduce the creep value of concrete. On this basis, finite element analysis was applied to calculate the vertical deformation of concrete beams in the two tensioning schemes, which proved the validity of the test conclusion. It is demonstrated that tensioning at early ages may significantly reduce the creep value of pre-stress concrete beams.

Keywords: early age; pre-stressed beam; creep; test; finite element analysis

作者簡(jiǎn)介：熊維，博士，講師，Email:xw7745@sohu.com。

參考文獻(xiàn)

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