PROCEDURE FOR QUALITY CONTROL ON THE LOCAL BLAST FURNACE SLAG USED IN CEMENT AS CEMENTITOUS SUPPLEMENTARY MATERIAL

摘要

Blast furnace slag is a by-product with constant chemical and mineralogical characteristics, because of it's metallurgical and thermodynamical constraints. Slag has cementitious properties and due to that it is used mixed with portland cement to make slag cement, which has good compressive strength performance. Moreover, slag has a much more constant composition than fly ash. The basicity, the temperature and rate of cooling of slag, are the main characteristics, which determine its hidraulicity. The main objectives of the procedure for quality control on the local blast furnace slag are: 1. Description of the basic characteristics of the slag, by chemical ratio and mineralogical composition 2. Determination of the effects of slag on cement, by hydraulic index, which is a ratio between the 28 d compressive strength of 50/50 blend of ground slag and Portland cement and 28 d compressive strength of reference Portland cement. This paper presents also a comparison of slag cements with composite cements realized with pozzolanic materials, obtained in similar experimental conditions. Slag can be used for performent cement, if it is used in conjunction with tuffs and fly ashes.