Title:
Properties of Concrete Incorporating Natural and Crushed Stone Very Fine Sand
Author(s):
Ahmed A. E. Kourd
Publication:
Materials Journal
Volume:
86
Issue:
4
Appears on pages(s):
417-424
Keywords:
bond stress; compressive strength; concretes; crushed stone; drying shrinkage; fine aggregates; flexural strength; limestone; performance; sands; shrinkage; Materials Research
DOI:
10.14359/2201
Date:
7/1/1989
Abstract:
The influence of natural and crushed stone very fine sand (finer than 75 micron) on the performance of fresh and hardened concrete was investigated. The tests were conducted on two series of concrete mixtures. Series A consisted of mixes having a constant slump of 100 ñ 15 mm (4 ñ 0.5 in.), and Series B contained mixes with a water-cement ratio of 0.70. The mixes of each series incorporated different percentages of very fine sand (VFS) as a replacement for fine aggregate. Results indicate that the water demand increases rapidly when the VFS replacement is more than 5 percent in natural sand concrete and more than 15 percent in crushed stone sand concrete. Water/bleeding data indicate a definite beneficial effect from the incorporation of more VFS in the fine aggregate. Furthermore, the compressive strength of constant slump concrete decreased linearly with increasing percentage of VFS replacement; the flexural and bond strength were similarly affected. For concretes with constant water-cement ratio, incorporation of VFS resulted in significant reduction in slump. Although the compressive strength of natural sand concrete was not significantly affected by the incorporation of VFS, crushed stone sand concrete indicated an increase in strength.