— circular wire and strand wrapped prestressed concrete environmental structures

... OF PRESTRESSED CONCRETE STRUCTURES 372R-7 Fig 2.1—Typical wall section of a wire- or strand- wrapped, cast-in-place, vertically prestressed tank Fig 2.2—Typical wall section of a wire- or strand- wrapped, ... circular wire- or strand- wrapped prestressed concrete structure Tendon—A steel element, such as wire, bar, cable or strand, or a bundle of such elements, used to impart prestress to concrete ... recommendations 5.2—Liquid-loss limit 5.3—Visual criteria 5.4—Repairs and retesting Chapter 6—References, p 372R-19 6.1—Referenced standards and reports 6.2—Cited references Appendix A—Recommendations and considerations...

Ngày tải lên: 24/10/2014, 17:26

... deflection, cracking and fatigue control under specified loading combinations Type of Steel Prestressing Stage Stress-relieved strand and wire, fpu = 0.85 fP” Low relaxation strand and wire, fpu = 0.90 ... provisions for prestressed concrete as well as nonprestressed concrete However, the torsion design provisions in this code are applicable only to nonprestressed concrete and not to prestressed concrete ... the concrete and the nonprestressed reinforcement The stress limitations are discussed in Sections 5.5 and 5.8 5.3.2 - Prestressed Members 5.3.2.1 -Concrete Flexural stresses in prestressed concrete...

Ngày tải lên: 24/10/2014, 21:58

... tendons-Strands, wire, or highstrength bars are used for tendons in prestressed concrete a Strands Two grades of seven -wire, uncoated, stress-relieved steel strand are generally used in prestressed concrete ... high 2.6.2 Reinforced, partially prestressed, and prestressedThis report covers use of reinforced concrete, partially prestressed concrete, and fully prestressed concrete The possible use of pretensioning ... Admixtures for Concrete M 195-84 Lightweight Aggregates for Structural Concrete Uncoated Seven -Wire Stress-Relieved Strand M 203-83 for Prestressed Concrete Uncoated Stress-Relieved Wire for Prestressed...

Ngày tải lên: 24/10/2014, 16:04

... MANUAL OF CONCRETE PRACTICE 3.3—Wall design 3.4—Roof design Chapter 4—Construction procedures, p 373R-9719 4.1 Concrete 4.2—Shotcrete 4.3—Forming 4.4—Nonprestressed steel reinforcement 4.5—Prestressing ... 373R-97-23 5.1—Testing 5.2—Acceptance criteria 5.3—Visual criteria 5.4—Repairs and retesting Chapter 6—References, p 373R-97-23 6.1—Recommended references 6.2—Cited references CHAPTER 1—GENERAL 1.1—Introduction ... 4.5—Prestressing tendons 4.6—Tolerances 4.7—Seismic cables 4.8—Waterstops and sealants 4.9—Elastomeric bearing pads 4.10—Sponge rubber Fillers 4.11—Cleaning and disinfection Chapter 5—Acceptance criteria...

Ngày tải lên: 24/10/2014, 17:26

Ngày tải lên: 12/10/2016, 18:39

Ngày tải lên: 03/05/2017, 11:17

... are two kinds of beam, namely, conventionally prestressed concrete beam with external cables (below referred as “typical beam”) and prestressed concrete beam with large eccentric cables (below ... of the lack of bond between the concrete and the cable -110- External Cable Imaginary concrete strain at cable level Deviator Concrete beam Fig.6.1 Imaginary concrete strain at the cable level ... the deviators and loading arrangement for the beams prestressed with external cables Both the effects of friction at the deviators and loading arrangement on the ultimate strength and increase...

Ngày tải lên: 07/11/2012, 11:04

... non -prestressed reinforcement in addition to the prestressing cables in the tension zone Prestressed Concrete Beams Bonded Prestressed Concrete Beams Perfectly Bonded Unbonded Prestressed Concrete ... namely, prestressed concrete beams with bonded cables and prestressed concrete beams with unbonded cables And in each group, beams can be divided into small subgroup For example, beams prestressed ... of concrete flanges and folded steel web or extradosed bridges with a short tower In this chapter, the definition of post-tensioned prestressed concrete beams and classification of beams prestressed...

Ngày tải lên: 07/11/2012, 11:04

... 188 wire troughs (for voice and data) will be mounted across the plywood frame between the VOICE and DATA blocks Cross -wire will run down and through the 188 wire troughs for VOICE and up and ... aware that the standards require all wire be concealed Fishing the walls, wire mold, and conduit placement are three methods of concealing wires The University standard for station wire is to fish ... Composition Composed of a 12 -strand 62.5 multi-mode and 10/125 um 12 strand single mode fiber riser rated cable, installed in innerduct, home run from the IDF to the MDF All strands must be terminated...

Ngày tải lên: 24/01/2014, 03:20

... reinforced concrete Imposed loads and imposed deflections Creep and relaxation of concrete Truss analogy Strut -and- tie analogy Continuity between the concepts of bending and arching action Prestressed concrete ... Lutyens, and built posthumously It appears to be a stone and concrete arch with brick spandrels, Figure 1.12 (a) In fact the spandrels conceal a steel portal structure, and the brick and Portland ... design of prestressed concrete bridges : concepts and principles / Robert Benaim p cm Includes bibliographical references and index Bridges, Concrete Design and construction Reinforced concrete...

Ngày tải lên: 18/02/2014, 18:20

... spatial configuration (such as the extent of openness and spatial definition, the normal function and/ or use of the place, and the age of the site and its upkeep) form additional bases for the perceptive-evaluative ... evasion and compatibility However, the results of our research—given the objective of characterizing the main scenic resources of a city—show that the main differences between attractive and unattractive ... attributes—developed in an exploratory manner in this work—suggest that restorative places tend to be open, luminous, and coherent, and are places for leisure and for meeting people It is, however, surprising...

Ngày tải lên: 19/02/2014, 17:20

... Develop and disseminate resources and tools for pollution prevention and environmental practitioners to help them better understand and become more proficient in lean manufacturing techniques and ... lean manufacturing, environmental performance, and the environmental regulatory framework The goal of this effort was to help public environmental agencies better understand the environmental implications ... breakdowns, equipment setup and adjustment losses, idling and minor stoppages, reduced speed, defects and rework, spills and process upset conditions, and startup and yield losses The ultimate...

Ngày tải lên: 15/03/2014, 19:20

... Magura’s formula, and it is generally used to calculate relaxation effects of the tendon material over time It can be assumed to be10 for most strand material and 45 for low relaxation strand A detail ... material properties for the girder, pier, and tendons Model / Properties / Material Type >Concrete ; Standard>ASTM (RC) DB>Grade C5000 ↵ Type >Concrete ; Standard> ASTM (RC) DB>Grade C4000 ↵ Name>Tendon ... Construction Stage Analysis of Prestressed Concrete Box Bridge (FCM) using General Functions First generate nodes, and then model right side of the prestressed concrete box girder using the Extrude...

Ngày tải lên: 01/04/2014, 03:20

... the centre, and is usually denoted by J Then equation (16.9) may be written T = -GJB L (16.11) Torsion of circular shafts and thin-walled tubes 370 We may combine equations (16.8) and (16.1 1) ... radius and in the plane of the cross-section, Figure 16.3 16.4 Torsion of a hollow circular shaft It frequently arises that a torque is transmitted by a hollow circular shaft Suppose a, and u2 ... stress (T at all points of the shaft Figure 16.8 Shearing and direct stresses due to combined torsion and tension Torsion of circular shafts and thin-walled tubes 376 If T is the shearing stress...

Ngày tải lên: 08/04/2014, 11:29

... the wires or strands are stressed; in Stage the concrete is cast around the stressed wires/strands; and in Stage the prestressed in transferred from the external anchorages to the concrete, once ... different forms the steel may take are: • Wires: individually drawn wires of mm diameter; • Strands: a collection of wires (usually 7) wound together and thus having a diameter that is different ... Advantages of Prestressed Concrete The main advantages of prestressed concrete (PSC) are: Smaller Section Sizes Since PSC uses the whole concrete section, the second moment of area is bigger and so...

Ngày tải lên: 01/05/2014, 09:45

... Loads and then Point and Uniform from the submenu to display the Point and Uniform Span Loads dialog box 25 In this dialog box: • Verify that the Load Case Name is DL • In the Load Type and Direction ... Reinforcing Yield Stress, fy edit box • Type in the Concrete Strength, fc edit box • Type 60 in the Shear steel Yield Stress, fys edit box • Type in the Concrete Shear Strength, fcs edit box • Accept ... right-hand corner of the 3-D View window to close it From the Define menu select Materials to display the Define Materials dialog box Click on CONC in the Materials area to highlight (select) it, and...

Ngày tải lên: 06/07/2014, 09:20

... provide cork (Q suber), and fuelwood, and are often components of ancient agro-forestry systems including substantial mixed woodland-pasture areas in Spain and Portugal and mixed coppice-pasture ... attack, and basidiomycete root rots (eg, Armillaria spp and Collybia spp) Much excellent observational and chronological evidence has been accumulated (Anon, 1990; Siwecki and Liese, 1991; Luisi and ... of northern and central Europe are dominated by the deciduous forest species Quercus robur and Q petraea, which provide a major renewable timber resource The oak savannah woodlands and maquis...

Ngày tải lên: 08/08/2014, 18:21

... plots of land are being selected, the assignment of different experimental conditions to the plots of land should be done randomly, by the use of a table of random numbers or some other randomizing ... ± infinity in value, and m1 m2 m3 f(X) (18) s12 s2 ϩ N1 N ^ ^ where m1 and m2 are the sample means, s2 and s2 are the 1 sample variances, N1 and N2 are the sample sizes and the X (σ UNITS) FIGURE ... and J C Geyer, Water Supply and Wastewater Disposal, John Wiley and Sons, Inc., New York, 1954 Feller, W., An Introduction to Probability Theory and Its Applications, 3rd Ed., 1, John Wiley and...

Ngày tải lên: 10/08/2014, 20:20

... low genotypic risk categories (rg and rog); (b) high and low environmental risk categories (re and roe); (c) four categories based on combined genotypic and environmental risk re = γRge + (1-γ) ... Vg+Ve VP is input and a single solution for Ve and Vg calculated Heritabilities are given by: H2 = Vg/VP h2 = VA/VP Ve and ε are input and Vg and Vge calculated, for a chosen cMD and all possible ... matrix method of Li and Sacks [46] Define the probability that an affected proband is in genotypic risk category z and environmental risk category w as Pzw and assume that risks are randomly distributed...

Ngày tải lên: 13/08/2014, 16:21