ABSTRACT
The mortar cube crushing strength, compressive and tensile strength of concrete from three
locally manufactured cements were tested.
The three cements tested were manufactured by Bamburi Cement brand name Nguvu, E.
African Portland Cement company brand name Blue triangle and Mombasa Cement brand name
Nyumba all Portland cement 32.5 were tested for mortar strength separately and results
compared.
The fine aggregates and coarse aggregate were graded and tested for Aggregate crushing value
(ACV) and flakiness index. Concrete was mixed for each cement brand, casted cured and tested.
The fresh concrete was tested for workability i.e. slump test and compaction factor test. In the
hardened state, Compressive and tensile tests were done.
The concrete from the three brands met the required 25 N/ (mix ratio M25 adopted) though
there were variations in both the fresh and hardened test done, the variation can be attributed to
different chemical composition and degree of quality control adopted by both the manufactures
and the carrying out the test. The 28 day cube crashing test result for class 25 concrete (M25)
showed that Bamburi Cement had the highest strength 31.3 N/ followed by Mombasa
cement 27.9N/ then finally 25.5N/ for Blue triangle .All the binders had a value higher
than the minimum required strength of 25 N/ .
For the mortar strength test all the binders did not achieve the required strength of 32.5 N/
due to use of river sand that was necessitated by unavailability of Standard sand. Bamburi had
the highest 30 N/ followed by Blue triangle 28.6 N/ then finally Mombasa cement
28.2 N/ .