Strength and Workability of Concrete with Inclusion of Fly Ash, Quarry Dust and a Generic Naphthalene-based Super Plasticizer

Abstract

Poor strength and workability often result in low quality concrete that can cause structural failures. This research work was conducted to improve the strength and workability of concrete at reduced amount of water due to the addition of super plasticizer by replacing partially the concrete materials: cement, with fly ash at 0%, 5%, 10% and 15%; fine aggregate, with quarry dust at 0% and 15%; and the addition of sulphonated Naphthalene Formaldehyde Condensate (SNFC) super plasticizer at 0% and 0.6% by weight of cement content reducing the amount of water to 0.45 w/c from the conventional 0.6 and 0.55 w/c ratio. Concrete cube specimens were prepared with these inclusions using grade M20 concrete and nominal mix proportion of 1:2:4. Sieve analysis test, specific gravity test, fineness test were carried out on the concrete materials, workability test was carried out on each concrete specimen, a compressive strength test and weight density test was done at 7days and 28days curing. The compressive strength of concrete made with fly ash, quarry dust and SNFC at 28days ranges from 19.58N/mm2 to 30.23N/mm2. These results were higher compared to those of conventional concrete. A combination of fly ash, quarry dust and SNFC was then recommended for solving problems of low-strength concrete.