Accession Number : ADA327652

Title :   Construction Productivity Advancement Research (CPAR) Program. Development of High-Performance Lightweight Concrete Masonry Units.

Descriptive Note : Final rept.,

Corporate Author : CONSTRUCTION ENGINEERING RESEARCH LAB (ARMY) CHAMPAIGN IL

Personal Author(s) : Sweeney, Steven C. ; Brady, Pamalee A. ; Tadros, Maher K. ; Krause, Gary L. ; Bowser, Joan D.

PDF Url : ADA327652

Report Date : JUN 1997

Pagination or Media Count : 145

Abstract : Masonry construction continues to predominate in U.S. military construction and other sectors, but there has been little improvement in masonry structural technology for several decades. Without improvements in materials and productivity, the cost of masonry construction will significantly increase. To help keep masonry construction affordable, the U.S. Army Construction Engineering Research Laboratories (USACERL) initiated a Cooperative Research and Development Agreement with the University of Nebraska Center for Infrastructure Research to develop a lightweight high-strength concrete masonry unit (CMU). The objective of this research was to merge high-strength concrete and lightweight concrete technologies to produce a high-performance lightweight CMU up to 50 percent lighter than normal-weight units while maintaining or improving structural characteristics. The work produced a new type of high-strength lightweight CMU that can be manufactured using industry-standard equipment and meets or exceeds all performance-based requirements for block masonry. Using expanded shale aggregates and an optimized unit shape as the primary innovative components, the high-performance lightweight CMUs weigh about 8.6 kg and have average net compressive strength of 4000 lb/in.2 The minimum void gradation of the expanded shale was modified to provide high strength, good durability, and a smooth, uniform texture. Details on mix design and optimized block shape are provided.

Descriptors :   *HIGH COSTS, *CONCRETE, *CONSTRUCTION, *LIGHTWEIGHT, *PRODUCTIVITY, *MASONRY, *BRICK, OPTIMIZATION, HIGH STRENGTH, EXPANSION, TEXTURE, MILITARY ENGINEERING, STRUCTURAL ENGINEERING, SHALE, INFRASTRUCTURE.

Subject Categories : Construction Equipment, Materials & Supplies

Distribution Statement : APPROVED FOR PUBLIC RELEASE