Alkali Silica Reaction and Sulfate Attack: Expansion of Limestone Calcined Clay Cement

2017 ◽  
pp. 165-169
Author(s):  
A. Favier ◽  
K. Scrivener
Keyword(s):  
Sulfate Attack ◽  
Alkali Silica Reaction ◽  
Calcined Clay

How Efficient are LC3 and GGBFS-Contained Mortar Mixtures Submerged into Na2SO4 Solution against External Sulfate Attack at an early Age?

2021 ◽  
Vol 902 ◽  
pp. 145-151
Author(s):  
Islam Orynbassarov ◽  
Chang Seon Shon ◽  
Jong Ryeol Kim ◽  
Umut Bektimirova ◽  
Aidyn Tugelbayev
Keyword(s):  
Synergistic Effect ◽  
Construction Materials ◽  
Sulfate Attack ◽  
Early Age ◽  
Weight Changes ◽  
Calcined Clay ◽  
Initial Strength ◽  
Sulfate Resistance ◽  
Dense Microstructure ◽  
Pozzolanic Materials

Ordinary Portland cement (OPC) is one of the most widely used construction materials in civil engineering infrastructure construction but it is susceptible to sulfate attack. One of the ways to improve the sulfate resistance of an OPC mortar/concrete is to replace a certain amount of OPC with different pozzolanic materials such as ground granulated blast furnace slag (GGBFS) and metakaolin. The use of pozzolanic materials to mortar/concrete not only enhances durability but also reduces carbon dioxide (CO2) emission due to the less usage of OPC at the initial construction state. As considering these aspects, limestone calcined clay cement (LC3) has been developed in recent decades. However, the influence of LC3 on sulfate attack resistance has not been fully evaluated. Therefore, this study investigated the efficiency of LC3 mortar mixtures against sulfate attack at an early age (approximately 4.5 months) after two different curing periods, namely 1-day and 3-day curing, since the strength of the LC3 mixture is lower than OPC mixtures. To evaluate the synergistic effect of a combination of LC3 and GGBFS on the sulfate resistance, the LC3 and OPC mixtures containing 25% GGBFS were also assessed in terms of density, porosity, compressive strength, volumetric expansion, and weight changes. The experiment results show that the expansion of the LC3 mixture regardless of the addition of GGBFS and an initial curing strength made a plateau after a rapid increase up to 7 days, while the expansion of the OPC mixture kept increasing throughout the period. Furthermore, the addition of GGBFS to OPC or LC3 mixture provides the synergistic effect on reducing the expansion due to sulfate attack. Therefore, if LC3 mixture has high initial strength (min. 15 MPa) and dense microstructure to minimize the penetration of sulfate ion into the mixture, it is expected that LC3 mixture is more efficient than OPC mixture against the sulfate attack.

Mitigation of Alkali–Silica Reaction in Limestone Calcined Clay Cement-Based Mortar

2020 ◽  
pp. 665-672
Author(s):  
Quang Dieu Nguyen ◽  
Mohammad Khan ◽  
Arnaud Castel ◽  
Taehwan Kim
Keyword(s):  
Alkali Silica Reaction ◽  
Calcined Clay

scholarly journals Calcined Clay Pozzolan as an Admixture to Mitigate the Alkali-Silica Reaction in Concrete

2014 ◽  
Vol 02 (05) ◽  
pp. 20-26 ◽  
Author(s):  
James Sarfo-Ansah ◽  
Eugene Atiemo ◽  
Kwabena Appiah Boakye ◽  
Delali Adjei ◽  
Albert A. Adjaottor
Keyword(s):  
Alkali Silica Reaction ◽  
Calcined Clay

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).

scholarly journals Properties of Western Cape Concretes with Metakaolin

2018 ◽  
Vol 199 ◽  
pp. 11011
Author(s):  
Alice T. Bakera ◽  
Mark G. Alexander
Keyword(s):  
Dilution Effect ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Superior Performance ◽  
Alkali Silica Reaction ◽  
Western Cape ◽  
Western Cape Province ◽  
Calcined Clay ◽  
Global Demand ◽  
Strength And Durability

A global demand for affordable, sustainable, and durable concrete has resulted in growing use of Supplementary Cementitious Materials (SCMs). In the Western Cape Province of South Africa, the readily available SCM is Granulated Ground Corex Slag (GGCS), although fly ash can also be obtained. However, the availability of these SCMs, particularly GGCS, is subject to market and other extraneous factors, and this may render them vulnerable as sources of SCM for concrete. This points to the need for innovation and investigating other potential SCMs which are economically and environmentally effective. Metakaolin, a high-grade type of calcined clay, emerges as a possible potential future SCM in the Western Cape. This study aimed at investigating the influence of a locally available metakaolin on mechanical (compressive and tensile strength), and durability (concrete penetrability and potential to mitigate Alkali Silica Reaction (ASR)) properties of Western Cape concrete. In comparison to GGCS, concretes with metakaolin showed superior performance in both mechanical and durability properties. This was attributed to its role in concrete in terms of accelerating hydration reactions, pozzolanic activity, and dilution effect. Metakaolin can therefore be regarded as a beneficial substitute for GGCS in Western Cape concrete. However, questions that remain include cost-effectiveness, and the awareness and willingness of industry to incorporate this material.

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.

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