Research Article
Prestress Loss of CFL in a Prestressing Process for Strengthening RC Beams
Table 1
Measuring results for the strains of CFL (µε).
| | Specimen | Initial strain | Prestress levels | Strain loss | | During tension (proportion) | During bonding (proportion) | During curing (proportion) | During release (proportion) | Long-term (proportion) | Total strain loss (proportion) |
| | PB-8-1 | 1566 | 8% | −140 (−8.9%) | 55 (3.5%) | −43 (−2.7%) | | | −203 (−13.0%) | | PB-8-2 | 1597 | 8% | −146 (−9.1%) | 63 (3.9%) | −51 (−3.2%) | | | −234 (−14.7%) | | PB-8-3 | 1569 | 8% | −120 (−7.6%) | 56 (3.6%) | −48 (−3.1%) | | | −214 (−13.6%) | | PB-8-4 | 1533 | 8% | −98 (−6.4%) | 58 (3.8%) | −44 (−2.9%) | | | −160 (−10.4%) | | PB-8-5 | 1599 | 8% | −154 (−9.6%) | 67 (4.2%) | −49 (−3.1%) | | | −239 (−14.9%) |
| | PB-15-1 | 2908 | 15% | −209 (−7.2%) | 52 (1.8%) | −67 (−2.3%) | | | −350 (−12.0%) | | PB-15-2 | 2932 | 15% | −190 (−6.5%) | 65 (2.2%) | −81 (−2.8%) | | | −364 (−12.4%) | | PB-15-3 | 2970 | 15% | −214 (−7.2%) | 62 (2.1%) | −62 (−2.1%) | | | −358 (−12.1%) | | PB-15-4 | 3060 | 15% | −235 (−7.7%) | 69 (2.2%) | −83 (−2.7%) | | | −416 (−13.6%) | | PB-15-5 | 2931 | 15% | −190 (−6.5%) | 55 (1.9%) | −55 (−1.9%) | | | −317 (−10.8%) |
| | PB-22-1 | 4313 | 22% | −280 (−6.5%) | 49 (1.1%) | −59 (−1.4%) | | | −495 (−11.5%) | | PB-22-2 | 4386 | 22% | −320 (−7.3%) | 65 (1.5%) | −82 (−1.9%) | | | −534 (−12.1%) | | PB-22-3 | 4389 | 22% | −327 (−7.5%) | 71 (1.6%) | −94 (−2.1%) | | | −551 (−12.6%) | | PB-22-4 | 4357 | 22% | −268 (−6.2%) | 53 (1.2%) | −63 (−1.4%) | | | −498 (−11.4%) | | PB-22-5 | 4368 | 22% | −291 (−6.7%) | 73 (1.7%) | −91 (−2.1%) | | | −533 (−12.2%) |
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Note. In the name of each specimen, PB means prestressed beam, the first number is the prestress level, and the second number is a serial number.
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