Description Significant revisions were made in Chapter 9 of ACI 318-02to the load factors to be used for determining required strength. The load factor for dead load was reduced from 1.4to 1.2, and the load factor for live load was reduced from 1.7to 1.6; other changes were also made as given in equations for required […]
Description Three experimental flat plat structures were erected at the Division of Building Research, Commonwealth Scientific and Industrial Research Organization, Melbourne, Australia. The investigations were carried out under field conditions, the structures being completely exposed to the weather. Structure Mark I consisted of an expanded shale concrete slab, 3-l/2 in. thick, spanning three bays of
Description he majority of durability problems found in grouted post-tensioned structures are related to voids in the grout due to incomplete filling of ducts or bleeding of the grout. Voids in the grout within the duct result in a loss of the protective environment and may end up as a collection point for moisture or
Test Method for Bleed Stability of Cementitious Post-Tensioning Tendon Grout Read More »
Description This report is intended to provide general information on the corrosion and repair of grouted multistrand and bartend on systems. The information is intended to represent the state of knowledge of the committee in the areas of corrosion prevention in grouted tendons, as well as evaluation and repair. It is not intended as a
Report on Corrosion and Repair of Grouted Multistrand and Bar Tendon Systems Read More »
Description The following definitions govern in this specification. See “ACI Concrete Terminology” for additional definitions. http://www.concrete.org/Tools/ConcreteTerminology.aspxanchorage—a device used to maintain elongation in prestressing strand by transferring compression force to concrete. Architect/Engineer—the architect, engineer, architec-tural firm, or engineering firm developing Contract Docu-ments or administering the Work under Contract Docu-ments, or both. Contract Documents—a set of documents
Specification for Unbonded Single-Strand Tendon Materials (ACI 423.7-14) Read More »
Description This report provides general information on the evalua-tion of known or suspected corrosion problems in unbonded single-strand tendons, historical information on the types and components of unbonded tendons and on the durability and corrosion protection provisions in the building code, and describes typical repair methods in use today. Expertise in design, construction, evaluation, and
Report on Corrosion and Repair of Unbonded Single-Strand Tendons (ACI 423.4R-14) Read More »
Description This report is an update to the previous ACI-ASCE Committee 423 report entitled “Recommendations for Concrete Members Prestressed with Unbonded Tendons(ACI 423.3R-96).” Since the publication of that report and the four previous reports that it replaced, many previous recommendations have been incorporated into ACI 318-02.These recommendations have been prepared to provide a comprehensive guide
Recommendations for Concrete Members Prestressed with Unbonded Tendons (ACI 423.3R-05) Read More »
Description Brittle punching failure can occur due to the transfer of shear forces combined with unbalanced moments between slabs and columns. During an earthquake, significant horizontal displacement of a flat plate-column connection may occur, resulting in unbalanced moments that induce additional slab shear stresses. As a result, some flat platestructures have collapsed by punching shear
Guide to Seismic Design of Punching Shear Reinforcement in Flat Plates (ACI 421.2R-10) Read More »
Description In flat-plate floors, slab-column connections are subjected to high shear stresses produced by the transfer of the internal forces between the columns and the slabs. Section 11.11.3 of ACI 318-08 allows the use of shear reinforcement for slabs and footings in the form of bars, as in the vertical legs of stirrups. ACI 318
Guide to Shear Reinforcement for Slabs (ACI 421.1R-08) Read More »
Description This guide is provided to help designers take advantage of higher bond strength exhibited by high relative rib area bars(Darwin and Graham 1993; Darwin et al. 1996a; Zuo and Darwin 1998) in the calculation of tension lap splice length and development length of bar reinforcement. It includes expressions for development and lap splice length
