Effect of Binder Content and Solution/Binder Ratio on Alkali-Activated Slag Concrete Activated with Neutral Grade Water Glass

The paper assesses the durability of one-part alkali-activated slag-based mortars (AAS) in different aggressive environments, such as calcium chloride- and magnesium sulphate-rich solutions, in comparison with traditional cementitious mortars at equal water to binder ratio. Moreover, the freezing and thawing resistance was evaluated on mortars manufactured with and without air entraining admixture (AEA). Experimental results indicate that the alkali content is a key parameter for durability of AAS: the higher the alkali content, the higher the resistance in severe conditions. In particular, high-alkali content AAS mortars are characterized by freeze–thaw resistances similar to that of blast furnace cement-based mixtures, but lower than that of Portland cement-mortars while AAS with low activators dosages evidence a very limited resistance in cold environment. The effectiveness of AEA in enhancement of freeze–thaw resistance is confirmed also for AAS mortars. Moreover, AAS mixtures are quasi-immune to expansive calcium oxychloride formation in presence of CaCl2-based deicing salts, but they are very vulnerable to magnesium sulphate attack due to decalcification of C-S-H gel and gypsum formation.

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Enhancement of alkali-activated slag cement concretes crack resistance for mitigation of steel reinforcement corrosion

E3S Web of Conferences ◽

10.1051/e3sconf/202016606001 ◽

2020 ◽

Vol 166 ◽

pp. 06001

Author(s):

Pavlo Krivenko ◽

Oleh Petropavlovskyi ◽

Oleksandr Kovalchuk ◽

Igor Rudenko ◽

Oleksandr Konstantynovskyi

Keyword(s):

Crack Resistance ◽

Structure Formation ◽

Water Glass ◽

Sodium Metasilicate ◽

Steel Reinforcement ◽

Reinforcement Corrosion ◽

Slag Cement ◽

Alkali Activated Slag ◽

Activated Slag ◽

Alkali Activated

The paper is devoted to mitigation of steel reinforcement corrosion in alkali-activated slag cement (further, AASC) concretes, based on soluble sodium silicates (further, SSS’s), obtained from high consistensy concrete mixes. Enhancement of AASC fine concretes crack resistance due to modification by complex shrinkage-reducing additives (further, SRA’s) based on surfactants and trisodium phosphate Na3PO .12H2O (further, TSP) was proposed for mitigation of steel reinforcement corrosion. SSS’s were presented by sodium metasilicate (silica modulus 1.0, dry state) and water glass (silica modulus 2.9, density 1400 kg/m3). In case of sodium metasilicate the application of SRA composition “ordinary portland cement clinker – TSP – sodium lignosulphonate – sodium gluconate” provides enhancement of crack resistance starting from early age structure formation with restriction of drying shrinkage from 0,984 to 0,713 mm/m after 80 d. The effect is caused by reduction of water and by higher volume of crystalline hydrates. In turn, SRA presented by compositions “TSP – glycerol” and “TSP – glycerol – polyacrylamide” provide enhancement of AASC fine concretes fracture toughness during late structure formation with increasing ratio of tensile strength in bending to compressive strength up to 37 – 49 % if compare with the reference AASC when water glass is used.

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Factors Influencing the Strength of Alkali-Activated Slag Cement

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.368-373.3240 ◽

2011 ◽

Vol 368-373 ◽

pp. 3240-3245

Author(s):

Zhi Jun Zhou ◽

Hui Li ◽

Qiang Song ◽

Bao Jing Shen

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Silica Fume ◽

Water Glass ◽

Slag Cement ◽

Alkali Activated Slag ◽

Factors Influencing ◽

Activated Slag ◽

Alkali Activated

In this paper, water glass was chosen as activator to prepare Alkali-activated slag(AAS) cement. Effects of modulus and dosage of water glass, and admixture (fly ash, slag and silica fume) on the strength of AAS cement was investigated. It was found that the modulus of water glass had great effect on the strength of AAS cement when the mixing amount of water glass was less than 12%. With the incorporation of fly ash or slag, the strength of AAS cement decreased, however the incorporation of silica fume could promote the flexural and compressive strength of AAS cement slightly.

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Adsorption of Naphthalene-Based Water Reducer on Alkali-Activated Slag Cement

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.226-228.1747 ◽

2012 ◽

Vol 226-228 ◽

pp. 1747-1750

Author(s):

Chang Hui Yang ◽

Qun Pan ◽

Jiong Zhu

Keyword(s):

Zeta Potential ◽

Rheological Properties ◽

Water Glass ◽

Slag Cement ◽

Alkali Activated Slag ◽

Absolute Value ◽

Adsorption Of Water ◽

Activated Slag ◽

Alkali Activated ◽

Over Time

In this work, the adsorption of naphthalene-based water reducer (FDN) on slag ground with or without the composite retarder YP-3 and PN (YP) in alkali-activated slag cement (AASC) activated by water glass (WG) has been studied in detail. The results show that the effect of the adsorption of water reducer on AASC depends directly on the dosage of the water reducer and on the composite retarder used. For example, mixed slag particles adsorb thrice as much water reducer FDN than pure slag particles at 1% mass of the slag, and the absolute value increment of the zeta potential of the AASC suspension containing the composite retarder is 8.61 mV, compared with 1.99 mV in the system without the composite retarder. Moreover, the AASC pastes activated by WG containing the retarder YP show better rheological properties and lower fluidity loss over time.

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The Effect of Surfactant and Alkali on the Surface Tension of Simulated Solutions of Alkali Activated Slag Cement System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.399-401.1246 ◽

2011 ◽

Vol 399-401 ◽

pp. 1246-1250

Author(s):

Xian Feng Liu ◽

Jia Hui Peng ◽

Chang Hui Yang ◽

Yu Yan Shu ◽

Da Chang Wu

Keyword(s):

Surface Tension ◽

Water Glass ◽

High Viscosity ◽

Heat Of Hydration ◽

Slag Cement ◽

Alkali Activated Slag ◽

Cement System ◽

Cement And Concrete ◽

Activated Slag ◽

Alkali Activated

Alkali activated slag cement and concrete are high strength, rapid hardening, low heat of hydration, good durability and so on. Whereas, too high viscosity and bad workability of the fresh mixture is the crux of the matter to embarrass application of alkali-activated slag cement and concrete. Development of special superplasticizer for alkali activated slag cement and concrete is a worth exploring way to solve the problem, and the study on the surface tension of simulated solutions of alkali activated slag cement system is one of the basic researches about the special superplasticizer. In this paper, the surface tension of surfactant-alkali-water was studied by Wilhelmy method. The results showed, first, water-glass had the best efficacity of several alkali activators, when the modulus of water-glass was 1.5 and dosage of water-glass by Na2O was 8%, the surface tension was reduced by 33 mN/m and reduced to 39.9mN/m; second, [CH3(CH2)9]2N(CH3)2Cl had the best efficacity of several surfactants, when the concentration of [CH3(CH2)9]2N(CH3)2Cl was 50g/L, the surface tension was reduced by 35.3 mN/m and reduced to 32.5 mN/m; finally, the effect of surfactant and alkali together on the surface tension of water was complex, surfactants had hardly effective in water glass.

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Basaltic Crushed Rock Stabilized with Cementitious Additives: Compressive Strength and Stiffness, Drying Shrinkage, and Capillary Flow Characteristics

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1819b-03 ◽

2003 ◽

Vol 1819 (1) ◽

pp. 18-26 ◽

Cited By ~ 13

Author(s):

Srijib Chakrabarti ◽

Jayantha Kodikara

Keyword(s):

Capillary Rise ◽

Blended Cement ◽

Drying Shrinkage ◽

Basaltic Rock ◽

General Purpose ◽

Binder Content ◽

Alkali Activated Slag ◽

Basaltic Rocks ◽

Activated Slag ◽

Alkali Activated

Research was undertaken to increase knowledge of the properties of local stabilized pavement materials to facilitate their wider use in road construction and rehabilitation. Laboratory tests involved testing for the unconfined compressive strength (UCS), shrinkage, and capillary behavior of crushed basaltic rocks stabilized with two conventional cementitious binders—general purpose cement and lime—and two cementitious binders comprising industrial waste products—blended cement and alkali-activated slag. The alkali-activated slag and blended cement significantly increased UCS of untreated material and performed as well as or better than such traditional binders as general purpose cement. Overall, lime performed poorly as a stabilizer of crushed basaltic rocks, primarily because the fine content containing clay minerals was not significant in the crushed basaltic rock composition. UCS of stabilized materials increased significantly as binder content increased; UCS could be described as a function of binder quantity. Ultimate shrinkage increased with binder content for general purpose cement and alkali-activated slag, but for blended cement, behavior was different. The rate of drying shrinkage was relatively high at the early stage of shrinkage. Generally, alkali-activated slag produced less shrinkage compared with general purpose and blended cements. Capillary rise and water absorption were also measured. Test results indicated that the rate of capillary rise and amount of water absorbed by the material matrix decreased with the increase of binder content. The research indicated that the use of binders with industrial by-products could be a viable option in stabilization of crushed basaltic rock materials.

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