Accession Number : ADA331570

Title :   New Technologies for Improving the Consolidation of Concrete.

Descriptive Note : Final rept.,

Corporate Author : ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS

Personal Author(s) : Alexander, A. M. ; Haskins, Richard W. ; Sari, Al ; Soroushian, Parviz ; Hsu, Jer-Wen

PDF Url : ADA331570

Report Date : SEP 1997

Pagination or Media Count : 124

Abstract : Under the Construction Productivity Advancement Research (CPAR) Program, a new two-part system for improving the consolidation of concrete has been developed. First, a new vibratory consolidation subsystem was developed to enhance the efficiency and effectiveness of concrete consolidation in the context of a slipform paver. The system uses the phenomenon of resonance to efficiently vibrate a rigid and relatively large consolidation volume within concrete to relatively high-vibratory displacement amplitudes at a frequency appropriate for concrete consolidation. Dynamic finite element analysis and optimization techniques were used to design a mechanical system based on this concept which also satisfied the geometric requirement for installment in slipform pavers. The vibratory consolidation subsystem was then constructed, evaluated, and subjected to a comparative experimental study which revealed its advantages over conventional internal vibrators. A strain-gauge monitoring system was also devised and evaluated for real-time monitoring of the consolidation process of concrete under the action of the new system. A connection mechanism to interface between the new consolidation system and slipform pavers was devised, manufactured, and installed on a slipform paver. A large-scale field simulation was constructed for the purpose of evaluating the whole connection system under realistic operating conditions that closely simulated those of slipform pavers. Refinement of the hydraulic control and cooling system of the shakers that drive the resonant vibrators is going on currently. This will he followed by long-term longevity and fatigue evaluation of the complete system under realistic operation conditions on a slipform paver. Second, significant progress was made in the development of the other subsystem. It is an electrical impedance device that provides results in rea

Descriptors :   *CONCRETE, REQUIREMENTS, SIMULATION, SETTING(ADJUSTING), VOLUME, OPTIMIZATION, MONITORING, REAL TIME, AIR, ALTERNATING CURRENT, ELECTRICAL PROPERTIES, CONSTRUCTION, RESONANCE, FATIGUE, PRODUCTIVITY, HYDRAULICS, ELECTRICAL MEASUREMENT, MECHANICAL COMPONENTS, VIBRATORS(MECHANICAL).

Subject Categories : Ceramics, Refractories and Glass
      Construction Equipment, Materials & Supplies

Distribution Statement : APPROVED FOR PUBLIC RELEASE