Fineness Of Indigenous Cements Of Bangladesh And Its Effects On Initial And Final Settings

Abstract

Cement is the most common construction materials. It is expected that finer cement provides larger surface area for hydration thus sets early. But, due to other contents like fillers, gypsum etc. this phenomenon can be different. Non-structural cracks usually form on a mortar-plastered surface due to a number of different causes. Bangladesh being a developing country, construction industries are booming in the recent years. Thus, cement property tests have become an important quality control measure for concrete production. This paper will provide guidance to ensure cement quality by observing the general value of fineness of local cement brands and effect of fineness on consistency, initial and final setting times. Cracks developed on plastered surfaces under different curing conditions are also studied. It is found that consistency increases with increased fineness whereas setting times decreases. Insufficient curing leads to more cracks than prolonged curing (up to 7 days) aided low crack formation. Results suggested requirement of extended curing for at least 7 days and more.