scholarly journals Use of Pozzolan or Slag in Concrete to Control Alkali-Silica Reaction and Sulfate Attack

1988 ◽  
Author(s):  
Alan D. Buck
Keyword(s):  
Sulfate Attack ◽  
Alkali Silica Reaction

scholarly journals Durability of concrete containing ternary blends of high calcium fly ash and slag

2021 ◽  
Author(s):  
Seyon Kandasamy
Keyword(s):  
Fly Ash ◽  
Setting Time ◽  
Sulfate Attack ◽  
Alkali Silica Reaction ◽  
Ternary Blends ◽  
Fresh Properties ◽  
Freeze Thaw ◽  
Salt Scaling ◽  
High Calcium ◽  
High Calcium Fly Ash

This thesis investigates the performance of ternary blends containing high calcium fly ash (HCFA) and slag against: sulfate attack, alkali-silica reaction (ASR), salt scaling, and freeze-thaw damage. In addition, compressive strength, permeability and fresh properties were evaluated. In terms of sulfate attack, the performance of HCFA was significantly enhanced when slag was added to the mix, and the same was found for ASR. The high efficacy in resisting ASR of HCFA/slag blends was found to be a result of the blends' ability to bind and retain alkalis. Regarding the salt scaling, the tested ternary concretes failed the Ministry of Transportation Ontario limit, 0.8 kg/m²; however, enhanced performance was achieved when the samples were cured by wrapping with plastic sheets. Ternary blends achieved high resistance to freezing/thawing and less bleeding compared to those of the control mix without slag or HCFA; however, setting time was dragged by about an hour.

Effect of Mineral Admixtures on Durability of Concrete Structure Subjected to Alkaline Saline Corrosions

2006 ◽  
Vol 302-303 ◽  
pp. 68-72
Author(s):  
Quan Lin Niu ◽  
Nai Qian Feng
Keyword(s):  
Chloride Ion ◽  
Sulfate Attack ◽  
Mineral Admixtures ◽  
Alkali Silica Reaction ◽  
Sulfate Ion ◽  
Diffusion Test ◽  
Alkali Ions ◽  
Furnace Slag ◽  
Drying Test ◽  
Durability Of Concrete

Effect of a combination of alkali ions, sulfate ion and chloride ion on durability of concrete structures was analyzed, and the effect of different mineral admixtures on deterioration caused by Cl- penetration, sulfate attack and alkali-silica reaction was investigated. It is shown from wetting-drying test that sulfate attack on concrete was greatly relieved in high Cl- concentration solution, but diffusion test showed that Cl- diffusion was accelerated by SO4 2- ion existence as SO4 2- may incorporate with aluminum phase prior to Cl- ion. Replacement of cement with mineral admixtures such as ground blast furnace slag (SL) and metalaolin (MK) were beneficial for absorption of Cl- ion penetrated into paste, while ASTM C441 showed that fly ash (FA), metakaolin and natural zeolite (NZ) exhibited effectiveness in controlling Alkali-silica reaction (ASR).

Micro-Macro Material Performance Tests of One Attacked Building Foundation

2014 ◽  
Vol 1004-1005 ◽  
pp. 1478-1481
Author(s):  
Run Dong Gao ◽  
Hai Bin Chen
Keyword(s):  
Compressive Strength ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Energy Dispersive Spectrometer ◽  
Sulfate Attack ◽  
Alkali Silica Reaction ◽  
Performance Tests ◽  
Concrete Compressive Strength ◽  
Building Foundation ◽  
Scanning Electron

One 6-stories brick-concrete structure was built in the late of 1990s. The uneven settlement of the foundation had occurred and the average concrete compressive strength of the foundation was close to C30 standard. Apparent observations indicated that some white powdery substance which was not adhesive was precipitated at the aggregate/mortar interface, pores and cracks. Micro observations by means of a Scanning Electron Microscope equipped with a Energy Dispersive Spectrometer showed the coexistence of ettringite and small amount of alkali–silica gel, which proved that the foundation had suffered from sulfate attack and alkali–silica reaction.

scholarly journals Durability of concrete containing ternary blends of high calcium fly ash and slag

2021 ◽  
Author(s):  
Seyon Kandasamy
Keyword(s):  
Fly Ash ◽  
Setting Time ◽  
Sulfate Attack ◽  
Alkali Silica Reaction ◽  
Ternary Blends ◽  
Fresh Properties ◽  
Freeze Thaw ◽  
Salt Scaling ◽  
High Calcium ◽  
High Calcium Fly Ash

This thesis investigates the performance of ternary blends containing high calcium fly ash (HCFA) and slag against: sulfate attack, alkali-silica reaction (ASR), salt scaling, and freeze-thaw damage. In addition, compressive strength, permeability and fresh properties were evaluated. In terms of sulfate attack, the performance of HCFA was significantly enhanced when slag was added to the mix, and the same was found for ASR. The high efficacy in resisting ASR of HCFA/slag blends was found to be a result of the blends' ability to bind and retain alkalis. Regarding the salt scaling, the tested ternary concretes failed the Ministry of Transportation Ontario limit, 0.8 kg/m²; however, enhanced performance was achieved when the samples were cured by wrapping with plastic sheets. Ternary blends achieved high resistance to freezing/thawing and less bleeding compared to those of the control mix without slag or HCFA; however, setting time was dragged by about an hour.

scholarly journals The Impact of Aluminum- and Iron-Bearing Admixtures on the Resistance of Portland Cement Mortars to Alkali-Silica Reaction and Sulfate Attack

2015 ◽  
Vol 06 (06) ◽  
pp. 539-548
Author(s):  
Alexey Brykov ◽  
Anna Anisimova ◽  
Natalya Rozenkova ◽  
Mohammed Hadi ◽  
Maxim Mokeev
Keyword(s):  
Portland Cement ◽  
Sulfate Attack ◽  
Alkali Silica Reaction ◽  
Cement Mortars ◽  
The Impact ◽  
Iron Bearing

Expansive Reactions in Concrete Observed by Soft X-Ray Transmission Microscopy

1998 ◽  
Vol 524 ◽  
Author(s):  
K. E. Kurtis ◽  
P. J. M. Monteiro ◽  
J. T. Brown ◽  
W. Meyer-Ilse
Keyword(s):  
High Resolution ◽  
High Vacuum ◽  
Steel Corrosion ◽  
Advanced Characterization ◽  
Sulfate Attack ◽  
Alkali Silica Reaction ◽  
X Rays ◽  
Transmission Microscopy ◽  
Characterization Methods ◽  
X Ray

ABSTRACTAlkali-silica reaction, sulfate attack, and reinforcing steel corrosion can compromise the long-term durability of concrete structures. The anticipated economic impact of an extensive infrastructure repair scheme has produced a renewed interest in the development of advanced characterization methods to assess the degree of deterioration in the concrete experiencing these deleterious reactions. The products of the alkali silica reaction, sulfate attack, and corrosion as well as the cement hydration products are extremely sensitive to humidity. Consequently, characterization techniques that require high vacuum or drying, as many existing techniques do, are not particularly appropriate for the study of these reactions in concrete as artifacts are introduced. A high resolution instrument which allows the examination of these reactions and their products without drying and at normal pressures will promote understanding of the reactions and provide further insight into means of mitigating the damage they cause. Only soft x-ray transmission microscopy provides the required high spatial resolution to observe the reaction process in situ. The alkali-silica reaction can be observed over time, in a wet condition, and at normal pressures, features unavailable with most other high resolution techniques. Soft x-rays also reveal information on the internal structure of the sample. This paper reviews published and ongoing applications of soft x-ray transmission microscopy for the study of expansive reactions that occur in concrete.

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