Demonstration of Use of High-Performance Lightweight Concrete in Bridge Superstructure in Virginia |
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Authors: | Christopher J Waldron Thomas E Cousins Adil J Nassar Jose P Gomez |
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Affiliation: | 1Graduate Student, Via Fellow, Dept. of Civil and Environmental Engineering, Virginia Polytechnic Institute and State Univ., Blacksburg, VA 24061. 2Associate Professor, Dept. of Civil and Environmental Engineering, Virginia Polytechnic Institute and State Univ., 102B Patton Hall, Blacksburg, VA 24061-0105. 3Former Graduate Student, Dept. of Civil and Environmental Engineering, Virginia Polytechnic Institute and State Univ., Blacksburg, VA 24061. 4Associate Director for Structures, Pavements, and Asset Management, Virginia Transportation Research Council, 530 Edgemont Rd., Charlottesville, VA 22903.
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Abstract: | The general objective of this research was the construction and evaluation of a bridge using high-performance lightweight concrete (HPLWC). The resulting bridge over the Chickahominy River near Richmond, Va., consists of 15 prestressed American Association of State Highway and Transportation Officials (AASHTO) Type IV girders made of HPLWC with a density of 1,920?kg/m3 and a minimum required 28-day compressive strength of 55?MPa. The bridge also has a lightweight concrete (LWC) deck with a density of 1,850?kg/m3 and a minimum required 28-day compressive strength of 30?MPa. This research study is chiefly concerned with investigating the effects of using lightweight concrete in prestressed girders on transfer length, development length, flexural strength, girder live-load distribution factor, and dynamic load allowance. Transfer length was determined to be 432?mm, or 33?db, for several girders at the time of prestress transfer. The development length was determined to be between 1,830 and 2,440?mm, while the flexural strength ranged from 11 to 30% higher than the AASHTO flexural capacity. The measured distribution factors and dynamic load allowance were smaller than the AASHTO standard and LRFD values. |
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Keywords: | Bridge design Prestressed concrete Lightweight concrete High strength concretes Load distribution Flexural strength |
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