scholarly journals Influence of Additional Blast Furnace Slag, Anhydrate and Lime Stone Powder and Submerged Temperature on Sulfate Resistance of Ordinary Portland Cement Paste and Mortar

2012 ◽  
Vol 61 (2) ◽  
pp. 189-196
Author(s):  
Takahisa UCHIDA ◽  
Tsuyoshi SAITO ◽  
Yun sub LEE ◽  
Nobuaki OTSUKI
2010 ◽  
Vol 158 ◽  
pp. 1-11 ◽  
Author(s):  
Zi Qiao Jin ◽  
Xian Jun Lu ◽  
Shu Gang Hu

In order to stimulate the potential cementitious property of granulated blast furnace slag (GBFS), the ground GBFS sample (Wei Fang Iron and Steel Corporation, China) was activated by lime and gypsum under different dosages. The results showed that lime is an effective activator for the slag, and the optimum dosage of lime is about 10% (w/w) of the slag. At the optimum dosage of lime, the 28 days compressive strength of the lime-slag paste is higher than that of 32.5 ordinary Portland cement (OPC). But, the early age strength (3 and 7 days compressive strength) of the lime-slag paste is lower than that of the OPC. Addition of gypsum can effectively improve the early age strength of the lime-slag paste. At the ratio of gypsum:lime:slag of 8.2:9.2:82.6 (w/w), both the early and long-term compressive strengths of the gypsum-lime-slag paste are higher than that of the OPC. According to XRD, TG-DTA and SEM detections of the hydration products of the lime-slag paste, the gypsum-lime-slag paste and the OPC paste, it reveals that the hydration process of the GBFS-based cementitious material is different from the ordinary Portland cement and the presence of ettringite (AFt) contributes to the early age strength of the pastes. The major hydration product of the OPC paste (<7 days) were measured as ettringite (AFt), but the AFt phase was not detected in the hydration product of the lime-slag paste and the major hydration product of the lime-slag paste was determined as amorphous CSH gel. However, AFt was detected in the hydration products of the gypsum-lime-slag paste in the early stages of hydration, and the formation of AFt is favorable for the early strength improvement of the material.


2011 ◽  
Vol 239-242 ◽  
pp. 2389-2394
Author(s):  
Shu Gang Hu ◽  
Hai Li Niu ◽  
Xian Jun Lu

The blast-furnace slag (BFS)has been characterized by chemical and phase composition to evaluate its hydration reactivity. It has high potential activity for its glassy structure, so its use to prepare new filling cementation material is possible. New backfilling cementation material composition has been formulated and optimized by activation of BFS. The optimal formula of new backfilling cementation material SL(Slag activated by lime) and SLG(Slag activated by lime and desulfurization gypsum) was 87% BFS, 13% lime and 78.4% BFS, 11.8% lime, 9.8% desulfurization gypsum respectively. Finally, the feature of application performance was analyzed through comparison between new cementation material and ordinary Portland cement with paste and sand mortar experiment. The result showed that material SL and SLG have superior performance to ordinary Portland cement used to mining cemented filling.


1984 ◽  
Vol 42 ◽  
Author(s):  
Della M. Roy ◽  
G. M. Idorn

AbstractSubstantial increases of the strength of cement paste and mortars may be obtained in conventional processing by optimizing the materials components, the rheology and the curing, and thereby improving the microstructures. Cementitious materials with high proportions of granulated blast-furnace slag have been investigated. Higher strengths of ASTM C 109 mortars were obtained with 40 to 65% substitution of portland cement by slag, than with ordinary mix compositions and processing.For one set of mixtures, 28 day strengths ≥ 100 MPa (some as high as 240 MPa) were consistently attained after curing at temperatures ranging from 27 to 250°C. The slag substitutions developed finer pore structures as revealed by intrusion porosimetry measurements, than those with pure portland cement. This is believed to be a major reason for their enhanced durability. At each stage from 3 to 28 days, increase of curing temperatures from 27 to 90°C decreased porosity and increased the strength, reflecting an increased maturity.Implications for practice and suggestions for further work are discussed.


Sign in / Sign up

Export Citation Format

Share Document