Title:
Lightweight High-Performance Concrete Masonry-Block Mix Design
Author(s):
Babrak Amiri, Gary L. Krause, and Maher K. Tadros
Publication:
Materials Journal
Volume:
91
Issue:
5
Appears on pages(s):
495-501
Keywords:
aggregates; concrete blocks; fly ash; high-strength concretes; lightweight concretes; masonry; mix proportioning; silica fume; Materials Research
DOI:
10.14359/4075
Date:
9/1/1994
Abstract:
Concrete for masonry block is different from poured concrete in many ways. A zero slump mix is needed in concrete block mixes, while poured concrete usually requires some specific slump. Vibropress technology is generally used for compaction of the blocks, and the blocks are immediately demolded, unlike poured concrete construction. The texture of the blocks is one of the controlling factors in block mix design, and curing of concrete blocks takes place in special moisture- and temperature-controlled chambers, unlike poured concrete constructions. The design of lightweight high-performance concrete block mixes is summarized here. Factors involved in the mix design are discussed in detail. Laboratory test specimens, as well as plant-produced blocks, have been studied for strength, density, texture, and cost. It is demonstrated that units having 50 percent of the weight, 200 percent of the strength, and 125 percent of the material cost of normal weight standard units can be produced. When the potentially increased mason productivity due to laying lightweight units is included in the overall cost analysis, a cost savings is shown to be possible.