Title:
Gap-Graded Mixes for Cast-in -Place Exposed Aggregate Concrete
Author(s):
Albert Litvin and Donald W. Pfeifer
Publication:
Journal Proceedings
Volume:
62
Issue:
5
Appears on pages(s):
521-538
Keywords:
aggregate, architectural concrete, bushhammering, cast-in place concrete, exposed aggregate, field application, gap-graded aggregate, proporioning, sandblasting
DOI:
10.14359/7708
Date:
5/1/1965
Abstract:
Attractive uniform exposed aggregate surfaces of cast-in- place concrete may be achieved by the use of low-slump, gap-graded aggregate mixes. These mixes required a high percentage of coarse aggregate and low water-cement ratio, resulting in excellent strength and elastic properties with low creep and drying shrinkage. laboratory tests and field experience indicate that con-cretes with matrix volumes (air, water, cement, and sand) of 45 to 50 percent can be satisfactorily consolidated and will possess excellent architectural characteristics. The importance of special care in such matters as taping of form joints, proper treatment of form ties, adequate vibration, etc., is stressed. Three typical structures are cited in which cast-in-place, gap-graded concrete was used to obtain ex-cellent exposed aggregate surfaces.