The influence of fine aggregate combinations on particle size distribution, grading parameters, and compressive strength of sandcrete blocks

Abstract

The current extensive use of low priced fine aggregate (sand) deposits in sandcrete block making in Nigeria is of concern because there appears to be a level of ignorance surrounding their existing properties and implications. To this end, silt contents and some grading parameters of the most commonly used fine aggregate deposits in parts of midwestern Nigeria (Benin City), the coefficient of uniformity (Cu), curvature coefficient (Cc), and the fineness modulus (Fm) were derived by laboratory experiments to ascertain these basic properties. In addition, the strength and durability properties of sandcrete blocks made from these sands were also established. It revealed that the low priced sands exhibited worse properties in comparison to the more expensive sand. As a way of improving the properties of these frequently used low priced sands, a combination approach was adopted that used the weaker and commonly used sands with those that are more expensive and less frequently used. Findings revealed that combining the two created significant improvement in compressive strength, durability, and grading parameters of low priced sands with only marginal impact on cost.Key words: fine aggregates, uniformity coefficient, curvature coefficient, fineness modulus, compressive strength, durability, silt contents, Nigeria.