Concrete Structures Books
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
Description The transfer of forces across the interface between concrete and steel by bond stresses is of fundamental importance to many aspects of reinforced concrete behavior. Satisfactory bond performance is an essential goal in detailing reinforce-ment in structural components. Many detailing provisions in ACI 318 are aimed at preventing bond failures.Bond stresses in reinforced concrete
Report on Bond of Steel Reinforcing Bars Under Cyclic Loads Read More »
Description Seismic design practice worldwide is moving toward performance-based design of buildings. This approach aims at producing buildings capable of developing predict-able performance levels to achieve predefined performance objectives when subjected to earthquake ground motions. The performance objectives are met by ensuring the struc-ture and its components achieve target performance levels associated with different states
Description For seismic design, ACI 318-11 specifies in Section21.1.1.8 that “a reinforced concrete structural system not satis-fying the requirements of this chapter (Chapter 21) shall be permitted if it is demonstrated by experimental evidence and analysis that the proposed system has strength and toughness equal to or exceeding those provided by a comparable mono-lithic reinforced
Description Service-life concepts for buildings and structures date back to when early builders found that certain materials and designs lasted longer than others (Davey 1961). Throughout history, service-life predictions of structures, equipment, and other components were generally qualitative and empirical. The understanding of the mechanisms and kinetics of many degradation processes of concrete has formed
Service-Life Prediction (ACI 365.1R-00) Read More »
Description Concrete repairs can be broadly classified into structural and nonstructural. Structural repairs are designed to participate in carrying load and to protect the underlying concrete and embedded reinforcing steel from deterio-ration and corrosion. Nonstructural repairs are repairs designed for protection and/or aesthetic purposes only. The presence of cracks may adversely affect the load-carrying behavior
CRACKS IN A REPAIR (ACI 364.9T-03) Read More »
Description Hydro demolition is one of many methods available for concrete removal on horizontal, vertical, and over-head surfaces. This technique uses very high-pressure water (20,000 to 40,000 psi [140 to 280 MPa]) to remove concrete. Hydrodemolition has some advantages over other methods, including speed. Based on available evidence,1,2 it does not cause significant microcracking or
Description Bruising (microcracking) induced in a concrete substrate during the concrete removal or surface preparation process prior to repair is detrimental to the bond between the repair material and the substrate. Preventing or minimizing bruising and its effect on bond is an important requirement for a successful repair. Concrete repair projects commonly involve the removal
Description The performance of a reinforced concrete repair depends significantly on the condition of concrete in the reinforcement vicinity and on the quality of (re-)encapsulation. The extent of concrete removal prior to repair must be adjusted in accordance with the degree of contamination and the nature of distresses affecting the member or structure. When a
Concrete Removal In Repairs Involving Corroded Reinforcing Steel (ACI 364.6T-02(11)) Read More »
Description Concrete repairs may be broadly classified as structural (load-carrying) and nonstructural (protective and/or cosmetic). The load-carrying capacity and stress distribution must be considered in the case of structural repairs where replacement of deteriorated load-bearing concrete is required. The repair material may be subjected to tension, compression, and/or shear forces. Yet, even with equivalent or
Importance of modulus of elasticity In surface repair materials (ACI 364.5T-10) Read More »
Description In cases where a structural evaluation is to be performed, knowledge of member sizes, reinforcing details, and material properties is generally required. In cases where this information is not readily available through drawing document records, it should still be obtained. For most buildings, bridges, and structures governed by a building code or similar design
Description When epoxy-coated steel reinforcement is exposed in a repair area, the exposed reinforcement requires treatment prior to repair material placement During concrete removal and preparation of the repair area, the epoxy coating on the bars within the repair will be damaged, may already have defects or, as part of the repair procedure, be completely
Treatment of Exposed Epoxy-Coated Reinforcement in Repair (ACI 364.3T-10) Read More »
