Effect of Neem Seed Husk Ash on Concrete Strength Properties

Neem Seed Husk is a by-product obtained during industrial processing of Neem Seed to extract oil and produce fertilizer. Laboratory tests on Neem seed husk ash (NSHA) mixed with cement were conducted to find its effect on concrete strength and workability. Tests including slump test, compressive strength test, concrete density test and scanning electron microscope (SEM) were carried out on concrete partially replaced with 0%, 5%, 10%, 15%, 20% and 25%NSHA and presented. The test results indicate that concrete workability is affected by NSHA partial replacement by increase in the slump at 5% and 10% replacements. But it decreases the slump at 15%, 20% and 25% replacements. At 28 days curing, only the control (0% replacement) and 5% replacement satisfied the target compressive strength and therefore can be used for non-structural and mass concrete applications. Densities of most of the cubes partially replaced with NSHA are generally higher than that of the control concrete; this is further supported by the SEM. which indicates that NSHA act as filler and occupy the voids between the aggregates, thereby making the concrete more compact and having higher densities. All the samples have satisfied the density requirement of British standard for normal- weight concretehttp://dx.doi.org/10.4314/njt.v33i2.