Handling Internal Vibrators • Avoid vibrating too fast –Raise at 1 inch per second –This is the speed air rises in concrete • Avoid vibrating in irregular patterns – Patterns must overlap 1.5 times the radius of action –Ensures that all concrete is consolidated • ACI 309R states max. lift does not exceed 20 inches

Section 5.3.2.5 of ACI 301 states that unless otherwise specified, consolidate concrete by vibration. This applies to concrete slabs as well. In the Optional Requirements Checklist in ACI 301, Section 5.3.2.5 permits other methods of consolidation, too: “Specify if consolidating of concrete by methods other than vibration will be permitted.”

Difficulty consolidating concrete in reinforced and mass concrete structures continued to be a problem until the introduction of internal concrete vibrators in the early 1930s (McCarty 1933). The use of vibrators allowed stiffer mixtures with less water to be placed, increasing both concrete strength and durability and decreasing shrinkage. In

Chapter 13—Structural low-density concrete. 13.1—General. 13.2—Mixture requirements. 13.3—Behavior of structural low-density concrete during vibration. 13.4—Consolidation equipment and procedures. 13.5—Floors. Chapter 14—High-density concrete. 14.1—General. 14.2—Mixture requirements. 14.3—Placing techniques. Chapter 15 ...

Chapter 4—Consolidation of concrete by vibration, p. 309R-5 4.1—Vibratory motion 4.2—Process of consolidation Chapter 5—Equipment for vibration, p. 309R-6 5.1—Internal vibrators 5.2—Form vibrators 5.3—Vibrating tables 5.4—Surface vibrators 5.5—Vibrator maintenance Neil A. Cumming Kenneth C. Hover H. Celik Ozyildirim

The American Concrete Institute (ACI) is a leading authority and resource worldwide for the development and distribution of consensus-based standards, technical resources, educational programs, certification programs, and proven expertise for individuals and organizations involved in concrete design, construction, and materials, who …

Aug 1, 1997 · Keywords: Joint fillers; joints (junctures); roller compacted concrete; vibrators (machines). DOI: 10.14359/6110. Date: 8/1/1997. Abstract: Construction of transverse joints with lateral molds in RCD ( Roller Compacted Dam) method has been omitted because concrete layers are casted continuously.

Keywords: compacting; fresh concretes; mechanical drives;precast concrete; prefabrication; vibration (consolidation); vibrators (machinery). DOI: 10.14359/10514. Date: 12/1/1979. Abstract: In a number of cases large scale vibration of fresh concrete requires that more than one mechanical vibrator is built in the vibrator construction.

While in this condition, concrete settles under the action of gravity (sometimes aided by other forces). When vibration is discontinued, friction is reestablished (ACI 309R). References: SP-1(02); ACI PRC-309.5-22; ACI PRC-237.2-21. Topics in Concrete: Concrete Fundamentals; Consolidation of Concrete; Placing Concrete

concrete by vibration. Consolidate concrete around reinforcement, embedded items and into corners of forms to eliminate honeycombing or planes of weakness due to air voids and stone pockets. Unless otherwise specified, use the largest and most powerful internal vibrators to consolidate the concrete. Use immersion-type vibrators with nonmetallic