Optimization of Fineness of Ordinary Portland Cement Manufactured in Pakistan

• Published in: Mehran University Research Journal of Engineering and Technology Vol. 30; no. 4; pp. 549 - 558
• Main Authors: LIAQAT ALI QURESHI, SAEED AHMED
• Format: Journal Article
• Language: English
• Published: Mehran University of Engineering and Technology 01-10-2011
• Subjects: Clinker; Compressive Strength, Workability; Fineness; Grinding; Spectroscopy; Compressive Strength; Workability; Spectroscopy; Fineness; Clinker; Grinding
• ISSN: 0254-7821; 2413-7219

In this paper, investigation regarding impact of fineness of cement on properties of concrete is reported for cement manufactured by five different factories. Clinker was collected from a selected batch of each factory. It was ground along with 4% gypsum in a laboratory ball mill. From each factory, six cement samples with different fineness values were prepared. In order to confirm uniformity of their oxide ratios, their chemical composition was analyzed by XRF-Cement Spectroscopy. Grinding time for each sample was recorded by the built-in timer of ball mills. From the prepared samples, consistency tests of all the samples were performed in the laboratory. Concrete cubes having same mix. and water cement ratios were cast and tested for compressive strength at the age of 3, 7,and 28days. In order to have an idea of workability, slump test and compacting factor tests were carried out on concrete mixes prepared to cast test cubes. Comparisons were made between fineness of cement versus consistency of cement, compressive strength, slump, compacting factor of concrete, and grinding time. Mathematical relationships between fineness of cement and these parameters were established by using ＂Least Square Regression Method＂. Relative study of cost of grinding against desirable properties of cement ＆ concrete at higher fineness levels was also conducted.