This paper presents the effect of fineness of cement on properties of cement and concrete (in fresh and hardened state). The objective of this paper is to see these effects on the indigenous cement keeping other factors constant. It is a part of the series of research work carried out by the authors on cements manufactured by different factories using raw materials extracted from local quarries. In this work, fresh clinker having uniform chemical composition was collected from a factory. Clinker was ground in laboratory in a ball mill along with 4% gypsum. Six samples with fineness ranging from 1661 to 3674 cm2/g were prepared. British Standards were followed during this investigation. Consistency, setting time and expansion tests of cement were performed for all six samples. Mortar cubes were cast using Ottawa sand and their compressive strength tested at 3, 7 and 28 days. To see the effect of fineness of cement on properties of concrete, 6/1 x 6/1x 611 cubes (Mix ratio 1 :2:4 and water cement ratio 0.65) were cast and tested at the age of 3, 7 and 28 days. For workability of concrete, slump test and compacting factor tests for each mix were performed.
Graphs were drawn between the fineness and different properties of cement and concrete. While grinding clinker with gypsum, time taken by the ball mill in preparation of different samples was also noted. These values of time were plotted against respective finenesses of samples. From the curve attained, comparative study of cost of grinding against desirable properties of cement and concrete at high fineness levels was made possible.
It was noted that consistency of cement and compressive strength of concrete as well as of cement increased by increasing fineness of cement. The results are well in accordance with the previous published data regarding research work made on foreign cements. However, no general p attem could be obtained between fineness versus setting time and expansion of cement. As far as grinding cost is concerned, it was observed that as the fineness of cement increases, the grinding effort, hence, grinding cost increases