الفهرس 
Manufacturing of Portland CementOnly 14 pages are availabe for public view
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Abstract
Using Ground Granulated Blast Furnace (GGBF) slag, as sustainable source for
cementitious material, is world widely used for its low heat and durable advantages.Recently,several domestic cement companies started to dedicate production lines for manufacturing CEM III using GGBF slag imported from different foreign sources. In this research, the efficiency of two types of locally manufactured and lab prepared CEM III/A cement types, were investigated. The lab prepared CEM III/A
cement was made by replacing 50% of CEM I cement with imported very fine GGBF slag. On the other hand, the influence of partially replacing one of the selected locally manufactured CEM III/A cement by either 10% of Fly Ash(FA)or 20% Micro Silica fume (MS),was studied.Performance of all the mortar/concrete mixes made of these different blended cement types were compared with that made of Ordinary Portland Cement(CEM I).Generally, many advantages were monitored with using GGBF slag blended cement, such as, lower permeability, decreased chloride ion penetration. However, the aforementioned concrete properties enhancement was depending on the GGBF slag cement type and pozzolanic replacement materials. Significant enhancement was observed on water permeability (i.e. 67% reduction) and Chloride ion penetrability(i.e.71% reduction)of the concrete mixes having 10% MS weight replacement of GGBF slag blended cement(CEM III/A 42.5N-1). In addition, concrete durability characteristics and performance were positively affected by using Ground
Granulated Blast Furnace(GGBF)slag blended cement. Corrosion protection of
steel bars was enhanced, based on the recorded period for corrosion visual initiation, was significantly delayed (i.e. 350% and 426% delay) in case of replacing factory blended CEM III/A by 20% FA or 10% MS. Moreover, sulfate resistance was obviously improved after long period of different severe exposure conditions -wet and dry cycles of water, Na2so4 solution and H2SO4 solution long exposure-. Partial
replacement of CEM III cement by 10% fly ash or 20% micro silica provided higher endurance, with remarkable advantage to the later replacement case. Finally, based on Scanning Electronic Microscopy (SEM) photos, samples of modified slag cements by 10% or 20% of fly ash or micro silica respectively showed the densest
microstructures among all paste specimens made of the investigated cement types.