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Experimental study on prestress losses of post‐tensioned concrete members at ultra‐low temperatures
The use of prestressed concrete structures (PCSs) in extreme environments with low temperatures has increased over the years. In this study, two series of tests were carried out to evaluate the prestress losses of post‐tensioned PC specimens at ultra‐low temperatures. Twenty axially loaded PC specimens with different initial prestressing levels (0.40 and 0.65fptk) and moisture contents (water‐saturated concrete and naturally cured concrete) were tested at 20, −40, and −100°C. The total time‐dependent prestress losses of the specimens over a period of 10 h at 20, −40, and −100°C and the variations in prestress of the specimens during the cooling‐reheating process were investigated in this work. The results indicate that the time‐dependent prestress loss decreases with a decrease in temperature and initial prestressing level of the concrete. In contrast, the time‐dependent pressure loss decreases with an increase in the moisture content of concrete. It is worth noting that prestress increases when the concrete is cooled from −30 to −60°C because of the volumetric expansion of concrete. In addition, a simple method was proposed to estimate the prestress losses of PC specimens, which will greatly facilitate designers in predicting short‐term prestress losses of PCSs at ultra‐low temperatures.
Experimental study on prestress losses of post‐tensioned concrete members at ultra‐low temperatures
The use of prestressed concrete structures (PCSs) in extreme environments with low temperatures has increased over the years. In this study, two series of tests were carried out to evaluate the prestress losses of post‐tensioned PC specimens at ultra‐low temperatures. Twenty axially loaded PC specimens with different initial prestressing levels (0.40 and 0.65fptk) and moisture contents (water‐saturated concrete and naturally cured concrete) were tested at 20, −40, and −100°C. The total time‐dependent prestress losses of the specimens over a period of 10 h at 20, −40, and −100°C and the variations in prestress of the specimens during the cooling‐reheating process were investigated in this work. The results indicate that the time‐dependent prestress loss decreases with a decrease in temperature and initial prestressing level of the concrete. In contrast, the time‐dependent pressure loss decreases with an increase in the moisture content of concrete. It is worth noting that prestress increases when the concrete is cooled from −30 to −60°C because of the volumetric expansion of concrete. In addition, a simple method was proposed to estimate the prestress losses of PC specimens, which will greatly facilitate designers in predicting short‐term prestress losses of PCSs at ultra‐low temperatures.
Experimental study on prestress losses of post‐tensioned concrete members at ultra‐low temperatures
Xie, Jian (author) / Cui, Ning (author) / Yan, Jia‐Bao (author) / Yu, Jinghai (author)
Structural Concrete ; 20 ; 1828-1841
2019-12-01
14 pages
Article (Journal)
Electronic Resource
English
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