Development length of strands in prestressed panel subdecks

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by
Texas Transportation Institute , College Station
Bridges, Concrete -- Floors, Prestressed concrete, Reinforcing
Other titlesStudy of prestressed panels and composite action in concrete bridges ...
Statementby Harry L. Jones and Howard L. Furr.
SeriesTexas Transportation Institute. Research report 145-2, Research report (Texas Transportation Institute) ;, 145-2.
ContributionsFurr, Howard L., 1915- joint author., Texas Transportation Institute., Texas. Highway Dept.
Classifications
LC ClassificationsHE203 .T43 no. 145-2, TG340 .T43 no. 145-2
The Physical Object
Paginationviii, 43 p.
ID Numbers
Open LibraryOL5393530M
LC Control Number72610922

Development length required by the strands. An average development length 'of I 22 in. was required for the 3/8 in. diameter strands, and 34 in.

was needed for the strands with 1/2 in. diameters. The type of concrete used had little effect on development length, especially for.

Download Development length of strands in prestressed panel subdecks EPUB

An on-going study is thus evaluating the bond of prestressing strands on precast/prestressed girders. The study is based on experimental evaluation of transfer and development lengths of 13mm ( in.) diameter seven-wire strands on small-scale by: 4.

for strand development length: 7 Ld = 1. 5 ~: db - 4. 6 + (!ps - fse)db Jet (3) Tests conducted in at North Carolina State University (NCSU) found development lengths for un­ coated pretensioned strands that were significantly longer than predicted by Eq.

(l).s Pretensioning strand in use when the Hanson and Kaar tests were per­. Strand Development Length Bridge Deck Behavior for Interior Panel Configuration 7. Fu tu re W9rlc. corrosion of the prestressed strands.

Task 3 is the experimental program which project entitled "Precast Prestressed Concrete Panel Subdecks in Skewed Bridges". The development lengths for the prestressing strands in the rectangular and trapezoidal shaped panels was qualitatively investigated by monitoring strand slippage at the ends of selected prestressing strands.

The initial strand transfer length was established experimentally by monitoring concrete strains during strand detensioning, and this.

Overall, they found that the AASHTO LRFD [ 5] and ACI [ 6] code equations for development length of bottom strands are conservative and adequate for SCC. Ramirez and Russell [ 7] investigated bond and corresponding development lengths of mm and mm -diameter prestressing strand in high strength concretes.

In Article of the AASHTO specifications(1),the development length of a member is given by Equation as - Tfse)D (1) where D equals the nominal diameter of the strand in inches. This expression can be rewritten in terms of its con­ stituent parts (6) as where (2) = development length, = transfer length, and.

development length and lateral spacing requirements of prestressing strand for prestressed concrete bridge girders To respond to an FHWA memorandum restricting the use of certain sizes of seven-wire strand in prestressed concrete girders, the PCI sponsored a research program at the University of Tennessee at Knoxville.

The strand development length equation was first introduced in the ACI Building Code and was adopted by AASHTO in The original research that formed the basis for the derivation of the strand development length equation was conducted at the Development length of strands in prestressed panel subdecks book Cement Association (PCA) in the late s and early s.

SUMIDEN WIRE PRODUCTS CORPORATION Specifications for Prestressing Strand – Technical Data 1 SPECIFICATIONS FOR PRESTRESSING STRAND – TECHNICAL DATA. length are determined from ACI to be and in. ( and mm), respectively. The development length is therefore in. ( mm). Implicit in these calculations is a bond strength of psi ( MPa) over the transfer length and psi ( MPa) over the interior portion of the strand.

The transfer length is always a portion of the development length (figure 5). In figure 6, the transfer length can be seen going from zero to the dotted f se = ksi effective stress line, and the full development length goes all the way up to the dotted f pu = ksi line, where f pu is the specified ultimate strength of the strand.

For our ½” strand pulled to 31, lbs, and assuming 15%. panel subdecks is a factor to consider. Tests were conducted on 3¼ ino thick panels to determine the development length of the strands both initially and after repeated loading° For 3/8 ino diameter 7-wire strands tensioned with a force of 13o 75 kips an average development length of 22 in.

was required° For ½ ino diameter strands tensioned. Detailed studies on transfer and development length of seven-wire strands were initiated by Hanson The formulation is a summation of the transfer length l t (Eq. [3]) and the fexural bond length. The development lengths for the prestressing strands in the rectangular and trapezoidal shaped panels was qualitatively investigated by monitoring strand slippage at the ends of selected prestressing strands.

The initial strand transfer length was established experimentally by monitoring concrete strains during strand detensioning, and this length was verified analytically by a finite element.

top flange strands that helped control the top fiber stresses at time of prestress transfer and member camber making a total of eighty in.-diameter strands.

In Washington State, it is a common practice to drape about one third of the total number of bottom strands. The top strands also aided in the stability of the long, slender.

fies the minimum development length for prestressing strand in pretensioned members.* This equation is: ld = C.{ps-2fse/3)db where ld = development length, in. f. =stress in the strand at nominal strength, ksi fse = effective stress in the strand after losses, ksi db = nominal diameter of the strand, in.

One objective of this investigation is to determine the transfer and development length of inch­ and inch-diameter prestressing strands. The debonding, or blanketing, of strands is an alternative to draping strands in order to control the maximum concrete.

When designing prestressed concrete members, engineers must determine the development length of the prestressing strands. The development length is the sum of the transfer length and the flexural bond length. The transfer length is the distance from the free end of the prestressing strand necessary to fully bond the strand to the concrete.

It was concluded that: (1) the development lengths for O.S-inch and inch strands are adequately described by current AASHTO code provisionsj and (2) development length for the O.S-inch strand is approximately 72 inches, while that for the inch strand is approximately 84 inches.

development length of inch prestressing strand in standard i-shaped pretensioned concrete beams by r. barnes, n. burns, and m. kreger research report research project development length of mm (in.) diameter prestressing strand at mm (2-inch) grid spacing in standard i-shaped pretensioned concrete beams.

The results of an initial experimental program suggested that the full development length of mm and mm diameter unstressed prestressing strands embedded in a steel fiber reinforced UHPC. The transfer of prestress force from prestressing strands to the surrounding concrete is dependent on the bond between the two materials.

Understanding the actual bond stress distribution along the transfer length results in optimized design of the transfer zone of prestressed concrete members. Equations of estimating the transfer length in ACI code and AASHTO LRFD bridge.

It also determined the condition of the bond between the CIP concrete and the panels. Development Length of Strands in Prestressed Panel Subdecks, TxDOT Research ReportFurr & Jones, Texas Transportation Institute, Studies were made regarding development length of.

The development lengths for the prestressing strands in the rectangular and trapezoidal shaped panels was qualitatively investigated by monitoring strand slippage at the ends of selected prestressing strands. The initial strand transfer length was established experimentally by monitoring concrete strains during strand detensioning, and this length was verified analytically by a finite element analysis.

Precast prestressed concrete pavement (PPCP) is one such technique which has been demonstrated in recent years to meet this need. Precast panels can be produced well in advance of construction, stockpiled, and hauled to the site for installation as needed. PPCP can be constructed during non-peak travel times, such as overnight or during.

ℓ = Span length ℓd = Reinforcement development length ℓe = Strand embedment length from member end to point of maximum stress ℓf = Flexural bond length ℓt = Strand transfer length M = Service load moment Mcr = Cracking moment Md = Unfactored dead load moment Mg = Unfactored self-weight moment Mn = Nominal flexural strength.

Description Development length of strands in prestressed panel subdecks FB2

Abstract. Precast prestressed concrete panels have been used as subdecks in bridge construction in Iowa and other states. To investigate the performance of these types of composite slabs at locations adjacent to abutment and pier diaphragms in skewed bridges, a research prcject which involved surveys of design agencies and precast producers, field inspections of existing bridges, analytical.

Development Length Tests of Full-Scale Prestressed Self-Consolidating Concrete Box and I-Girders Journal of Bridge Engineering December Field Test of Magnetic Methods for Corrosion Detection in Prestressing Strands in Adjacent Box-Beam Bridges.

The use of the precast prestressed concrete panel technique in Texas, studies of 3 inservice bridges, and aspects such as strand development length and cyclic loading are discussed. Similar studies in Pennsylvania and Florida are also described.

Details Development length of strands in prestressed panel subdecks PDF

This final report is a supplement to an earlier report that covered the installation of the first precast, prestressed panel subdecks installed on a bridge in Virginia. The report discusses the inspection of the decks one year after they were completed and the relative ease of construction using the precast subdeck technique as opposed to.Insteel is the largest producer of PC strand in the United States.

We offer a complete line of seven-wire and three-wire, ASTM A compliant, ksi, low relaxation PC strand for prestress, posttension and mining applications.

Providing strands with a harped profile shape using hold-downs, normally a 2 points can also be used to achieve this. You need to read a good text on prestressed concrete design before you go any further if you do not already know this.

RE: Debonded Strands This resource will help you find key sessions-panels at DAC from researchers.