The Effect of Grinding Aids on Grinding Portland Cement with High Proportions of Slag

2012 ◽  
Vol 174-177 ◽  
pp. 191-197
Author(s):  
Su Zhen Sun ◽  
Yan Mei Yu

The paper brings information on grinding cement with high proportions of slag in the presence of amine alcohols grinding aids. Grind respectively blended cement with 20%, 50%, and 80% granulated blast furnace slag and analyse the evolution of the specific surface area at various grinding times and grindability. Results show that the specific surface area of belended cement depends on the content of slag and the type and ratio of grinding aid, and grindalility of the cement is also affected by grinding aids.

2014 ◽  
Vol 687-691 ◽  
pp. 4187-4191
Author(s):  
Guang Hui Cheng ◽  
Yuan Song

The change of the specific surface area, particle size and activity index of ground granulated blast furnace slag under different grinding conditions is researched based on closed-circuit mill in the paper. The research shows that the grinding effect is greatly different with the different grinding body, and proper pre-grinding time can help to improve the grinding effect. The optimum plan in this paper is as follow: pre-grinding 15 min at steel bar then grinding 30 min at ball grinding, and it will getting the maximum specific surface area, the smallest powder particle size and the the maximum activity index.


2007 ◽  
Vol 544-545 ◽  
pp. 503-506 ◽  
Author(s):  
Kyung Hoon Lee ◽  
Kwang Suk You ◽  
Ji Whan Ahn ◽  
Bong Chan Ban

The present study examined the effect of the activation properties of granulated blast furnace slag according to the type of alkaline activator, the specific surface area of blast furnace slag, and the amount of ordinary Portland cement substituted on the compressive strength of the cement containing blast furnace slag. For activators, Na2SiO3, Na2CO3, NaOH, and Na2SO4 were used. Na2SiO3, Na2CO3, and Na2SO4 were converted into Na2O, to which 1 wt.%, 3 wt.%, 5 wt.%, and 7 wt.% were added, and subjected to experimentation, with the W/S (water/solid) ratio = 0.5. The principal hydration products were C-S-H, C4AH13, Aft (ettringite), and Al(OH)3. Na2CO3 exhibited the largest slag hydration rate. Consequently, the present study used Na2CO3 as the alkaline activator. The compressive strength of blast furnace slag cement mortar was then measured according to the amount of Na2CO3 added (2.5 wt.% and 5.0 wt.%), the specific surface area of blast furnace slag (4,000 cm2/g, 6,000 cm2/g, and 8,000 cm2/g), and the substitution rate (30 wt.%, 50 wt.%, and 70 wt.%) of the blast furnace slag in terms of ordinary Portland cement. The results are as follows: at the ages of 1 day and 3 days, respectively, the early strength increased as the specific surface area of blast furnace slag and the amount of alkaline activator added increased; at the age of 7 or more days, the compressive strength increased as the amount of alkaline activator added decreased and as the specific surface area of blast furnace slag increased.


Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2984 ◽  
Author(s):  
Jinpeng Dai ◽  
Qicai Wang ◽  
Chao Xie ◽  
Yanjin Xue ◽  
Yun Duan ◽  
...  

To improve the properties of ground granulated blast furnace slag (GGBS) and utilize ground granulated blast furnace slag efficiently, this study investigates the effect of fineness on the hydration activity index (HAI) of ground granulated blast furnace slag. The hydration activity index of GGBS with six specific surface areas (SSAs) was characterized by the ratio of compressive strength of the prismatic mortar test block. The particle size distribution of GGBS with different grinding times was tested by laser particle size analyzer. The paste of different specific surface area GGBSs in different curing ages was investigated at the micro level by X-ray diffraction, scanning electron microscope, energy dispersive spectrometer, thermogravimetric scanning calorimeter, and differential scanning calorimeter. The effect of particle distribution of GGBS on the hydration activity index of different curing ages was studied by gray correlation analysis. The results indicated that the compressive strength and hydration activity index increases with the increase of a specific surface area of GGBS at different curing ages. The hydration activity index at different curing ages is almost a linear role for specific surface areas. With the increase in the specific surface area of GGBS, the content of Ca(OH)2 in paste decreases gradually. When GGBS was added into a mortar test block, the hydrate calcium silicate gel in paste changed from a high Ca/Si ratio to a low Ca/Si ratio. The 0–10 micron particles of GGBS particle distribution were highly correlated with the hydration activity index at different curing ages.


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3448
Author(s):  
Chenhui Jiang ◽  
Aiying Wang ◽  
Xufan Bao ◽  
Zefeng Chen ◽  
Tongyuan Ni ◽  
...  

This paper presents an experimental investigation on geopolymer coatings (GPC) in terms of surface protection of civil structures. The GPC mixtures were prepared with a quadruple precursor simultaneously containing fly ash (FA), ground granulated blast-furnace slag (GBFS), metakaolin (MK), and Portland cement (OPC). Setting time, compressive along with adhesive strength and permeability, were tested and interpreted from a perspective of potential applications. The preferred GPC with favorable setting time (not shorter than 120 min) and desirable compressive strength (not lower than 35 MPa) was selected from 85 mixture formulations. The results indicate that balancing strength and setting behavior is viable with the aid of the multi-componential precursor and the mixture design based on total molar ratios of key oxides or chemical elements. Adhesive strength of the optimized GPC mixtures was ranged from 1.5 to 3.4 MPa. The induced charge passed based on a rapid test of coated concrete specimens with the preferred GPC was 30% lower than that of the uncoated ones. Setting time of GPC was positively correlated with η[Si/(Na+Al)]. An abrupt increase of setting time occurred when the molar ratio was greater than 1.1. Compressive strength of GPC was positively affected by mass contents of ground granulated blast furnace slag, metakaolin and ordinary Portland cement, and was negatively affected by mass content of fly ash, respectively. Sustained seawater immersion impaired the strength of GPC to a negligible extent. Overall, GPC potentially serves a double purpose of satisfying the usage requirements and achieving a cleaner future.


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