EFFECTS OF SELECTED BRANDS OF PORTLAND CEMENT ON COMPRESSIVE STRENGTH OF CONCRETE

Abstract

The need to investigate the compressive strength of concrete produced with different brands ofcement obtainable within south east Nigeria formed the basis for the study. The study wasundertaken to assess the compressive strength of concrete produced with selected brands ofPortland cement obtainable within south east Nigeria. Four different brands of Portland cementnamely: Bua, Dangote 3x, Unicem and Lafarge were adopted for the study. The concretecomponents and the concrete were subjected to various laboratories testing which includes: sieveanalysis test, specific gravity test, aggregate impact and crushing value test, slump test andcompressive strength test. Sieve analysis test for the aggregate classified sand and granite as A-2-4 and A-1-b according to AASHTO Soil Classification System, SM (sand mixed with silt) and GC(gravel mixed with clay) according to Unified Soil Classification System, the specific gravity ofsand and granite were 2.55 and 2.66, the aggregate impact and crushing value were 27.6% and26.1% respectively, the initial and final setting time of Bua, Dangote 3x, Unicem and Lafargeranged from 28min – 30min and 560min – 600min, the fineness of the four different brands ofPortland cement ranged from 24.8% - 28.6%, the soundness of the cement ranged from 6.4% -8.3%. The slump of the fresh concrete produced with different brands of Portland cement rangedfrom 40mm – 55mm. The hardened density and compressive strength of the concrete producedwith Bua, Dangote 3x, Unicem and Lafarge were 2347kg/m3 , 2345kg/m3 , 2393kg/m3 and 2361kg/m3 and 24.18N/mm2 , 24.81N/mm2 , 27.47N/mm2, 27.15N/mm2 . It was observed that the highestdry density and compressive strength was recorded for concrete produced with Unicem while thelowest dry density and compressive strength was recorded for concrete produced with Dangote 3xcement. In the light of the findings, this study therefore recommends the use of Unicem cementfor production of both structural and non structural concrete due to significant attainment in drydensity and compressive strength.