详情

原文传递 Transversely posttensioned, pretopped box-slab system for precast concrete parking structures

题名：	Transversely posttensioned, pretopped box-slab system for precast concrete parking structures
正文语种：	英文
作者：	Maher K. Tadros;Kromel Hanna;Nader Jaber;Jenna Hansen
作者单位：	University of Nebraska-Lincoln;Zachry Engineering Corp
关键词：	Double tee;flange-to-flange connection;flanged box beam;parking structure;pretopped box beam;transverse posttensioning
摘要：	Precast concrete parking structures have proved their cost-effectiveness, speed of construction, and architectural elegance. The dominant precast concrete joist product in the United States for parking structures is the double tee. Research over the past 40 years has focused on improving the cost-effectiveness of double tees by increasing their width from 8 to 10 to 12 ft (2.4 to 3.0 to 3.6 m). Recently a 15 ft (4.5 m) wide double tee was introduced in some U.S. regions. Another active area of research has been to make the reinforcement of the spandrel beams simpler. This paper offers a precast concrete pretopped box slab with a wide top flange. The slab has a total depth of 24 in. (610 mm), compared with the corresponding 30 in. (76 mm) double tee, and a top flange width of 8 to 16 ft (2.4 to 4.9 m). The 12 ft'wide, 24 in. deep pretopped box slab is expected to replace the 12 ft wide, 30 in. deep double tee, and the 16 ft wide, 24 in. deep pretopped box slab is expected to replace the 16 ft wide, 30 in. deep double tee. This research shows that the new shape requires fewer strands than the double tee, and it theoretically and experimentally performs well. When considered in the total-precast concrete system described herein, it is expected to be competitive on both an initial and life-cycle cost basis. This paper also offers an innovative transverse posttensioning system to render the joints maintenance free and to eliminate the need for sealants, which have inspection demands and require occasional replacement. Details are given on how to get the joints precompressed while keeping the construction steps simple.
出版日期：	2017.03-04
出版年：	2017
期刊名称：	PCI-Prestressed Concrete Institute Journal
卷：	Vol.61
期：	No.02
页码：	48-60