| 释义 |
▪ I. pre-tension, n.2|priːˈtɛnʃən|
[f. pre- A. 2 + tension n.]
Tension in an object applied previously or at an early stage of a process, e.g. that applied to the reinforcing steel in the manufacture of prestressed concrete.
1936Structural Engineer XIV. 251/2 It is necessary to produce the pretension of the steel and to manufacture concrete of high resistance at a cost sufficiently low to allow one to preserve the greater part of the savings effected on the materials. 1941Concrete & Constructional Engin. XXXVI. 74/1 Shrinkage, elastic deformation, and creep under stress reduce the pre-tension by 10 tons to 20 tons per square inch. 1976G. S. Ramaswamy Mod. Prestressed Concrete Design i. 5 Inexpensive end anchorages are produced at the two ends of the bar to retain the pre⁓tension.
▪ II. pre-tension, v.|priːˈtɛnʃən|
[f. pre- A. 1 + tension v.]
trans. To apply tension to (an object) prior to some other treatment, esp. incorporation in a structure.
1937Rep. Building Res. Board 1936 (Dept. Sci. & Industr. Res.) 99 In connection with some tests on a particular lightweight aggregate, four beams have been tested to determine the effect of pre-tensioning the tension reinforcement. 1949P. W. Abeles Princ. & Pract. Prestressed Concrete ix. 63/2 A special process has been developed for the manufacture of hollow slabs in approximately 100 yd. long production lines, in which the wires are pre-tensioned in order to avoid any sag. 1973Sci. Amer. Apr. 114/1 The output of work per cycle can be increased somewhat by pretensioning the fiber before it is immersed in the brine.
Hence pre-ˈtensioned ppl. a., pre-ˈtensioning vbl. n. (freq. attrib.).
1936Structural Engineer XIV. 261/2 Thus, with two different steels, an effect was produced similar to that produced by M. Freyssinet's method of pre-tensioning. 1937Rep. Building Res. Board 1936 (Dept. Sci. & Industr. Res.) 98 The pre-tensioning apparatus is left in position until the concrete has hardened sufficiently to take the stresses induced in it. 1949P. W. Abeles Princ. & Pract. Prestressed Concrete ix. 58/2 Precast articles having pre-tensioned steel are mainly applicable to slabs, sleepers, beams, [etc.]..where mass production is possible. 1964C. W. Dunham Adv. Reinforced Concrete viii. 400 Pretensioned members can be used for other parts of a structure besides the floors and roof. 1965Economist 5 June 1176/1 The first multi-storey prestressed concrete building in the world combining pretensioned, prestressed roof beams manufactured in the factory with post⁓tensioning on site using the Magnel system. 1971J. R. Libby Mod. Prestressed Concrete xiv. 451 Pre-tensioning benches that can be moved from job site to job site have been used to a limited degree. 1975Kong & Evans Reinforced & Prestressed Concrete ix. 196 In pre-tensioning, the tendons pass through the mould, or moulds for a number of similar members arranged end to end, and are tensioned between external end anchorages, by which the tension is maintained while the concrete is placed. |