Properties of Alkli-Activated Slag Cement Compounded with Soluble Glasses with a High Silicate Modulus

2013 ◽  
Vol 712-715 ◽  
pp. 905-908
Author(s):  
Qun Pan ◽  
Bin Zhu ◽  
Xiao Huang ◽  
Lin Liu
Keyword(s):  
Compressive Strength ◽  
Cement Mortar ◽  
Strength Characteristics ◽  
Slag Cement ◽  
Alkali Activated Slag ◽  
Cement Mortars ◽  
Alkaline Activator ◽  
Activated Slag ◽  
Alkali Activated ◽  
High Silicate

Properties of alkali-activated slag cements compounded with soluble glasse with a high silicate modulus Ms=2.6 were detailedly studied in this paper, including compressive strength and flexure strength characterictics at the ages of 3,7,28 days and flow values of fresh cement mixtures on a jolting table. As a result, with the compressive strength at the age of 28 days of 95.6-107.8 MPa has been developed, and the flow values and strength characteristics of alkali-activated slag cement mortars increased with increase in a water to cement (alkaline activator solution to slag) ratio, and the flow value (determined on the cement mortar mixtures) would reach 145 mm. Moreover, the development speed of strength characteristics of mortar specimens would be affected negatively by increasing of water demand (requirement).

Effect of Dosage and Modulus of Water Glass on AC Impedance Properties of Alkali-Activated Slag Cement Mortar

2013 ◽  
Vol 423-426 ◽  
pp. 1018-1026
Author(s):  
Fu Qiang He ◽  
Xiao Peng An
Keyword(s):  
Compressive Strength ◽  
Water Glass ◽  
Cement Mortar ◽  
Ac Impedance ◽  
Slag Cement ◽  
Bulk Resistance ◽  
Alkali Activated Slag ◽  
Activated Slag ◽  
Alkali Activated

Compressive strength and AC impedance of mortar made with water-glass-activated slag were investigated as a dependence of modulus (0.5-2.0) and dosage (2-6%) of the water-glass. Results shown that when the dosage of water glass is 2- 4 %, the modulus of the water glass has a little effect on the compressive strength. In the case of the dosage of water glass is beyond 4 %, when modulus of the water glass change from 0.5-1.0, the compressive strength obviously increases with increase of modulus of water glass and when modulus of the water glass change from 1.0-2.0, the modulus of the water glass has a little effect on the compressive strength. The strength increases with increase of the dosage from 2 to 6%. In the case same dosage and modulus, there is a rather good power correlation between the bulk resistance and the activated age. With increase of the dosage, the bulk resistance significantly decreases when the dosage is below 4%. The decreasing degree is small when the dosage is beyond 4%. The decreasing degree derived from the dosage increases with the activated age. The effect of the modulus on the bulk resistance depends on range of the dosage. However, it can be regarded that when the dosage is 4% and 6%, the modulus has small effect on the bulk resistance in the case of all the dosages.

scholarly journals Effect of Sodium Aluminate Dosage as a Solid Alkaline Activator on the Properties of Alkali-Activated Slag Paste

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Bin Chen ◽  
Jun Wang ◽  
Jinyou Zhao
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Setting Time ◽  
Sodium Aluminate ◽  
Hydration Reaction ◽  
Hydration Products ◽  
Alkali Activated Slag ◽  
Alkaline Activator ◽  
Activated Slag ◽  
Alkali Activated

Extensive research into alkali-activated slag as a green gel material to substitute for cement has been done because of the advantages of low-carbon dioxide emissions and recycling of industrial solid waste. Alkali-activated slag usually has good mechanical properties, but the too fast setting time restricted its application and promotion. Changing the composition of alkaline activator could optimize setting time, usually making it by adding sodium carbonate or sodium sulfate but this would cause insufficient hydration reaction power and hinder compressive strength growth. In this paper, the effect of sodium aluminate dosage as an alkaline activator on the setting time, fluidity, compressive strength, hydration products, and microstructures was studied through experiments. It is fair to say that an appropriate amount of sodium aluminate could obtain a suitable setting time and better compressive strength. Sodium aluminate provided enough hydroxyl ions for the paste to promote the hydration reaction process that ensured obtaining high compressive strength and soluble aluminium formed precipitate wrapped on the surface of slag to inhibit the hydration reaction process in the early phase that prolonged setting time. The hydration mechanism research found that sodium aluminate played a key role in the formation of higher cross-linked gel hydration products in the late phase of the process. Preparing an alkali-activated slag with excellent mechanical properties and suitable setting time will significantly contribute to its application and promotion.

scholarly journals Effect of Cr6+ on the Properties of Alkali-Activated Slag Cement

2021 ◽  
Vol 8 ◽  
Author(s):  
Fu Bo ◽  
Cheng Zhenyun
Keyword(s):  
Compressive Strength ◽  
Setting Time ◽  
Cement Stone ◽  
Slag Cement ◽  
Hydration Kinetics ◽  
Alkali Activated Slag ◽  
Dual Beam ◽  
Press Method ◽  
Activated Slag ◽  
Alkali Activated

In order to investigate the effect of Cr6+ on the properties of alkali-activated slag cement (AAS), the effects of added dosage of Na2Cr2O4 on the setting time and compressive strength of AAS were measured. The leaching concentration of Cr6+ from AAS cement stone was measured using dual-beam UV-visible spectrophotometry. The effect of Na2Cr2O4 on the hydration kinetics of AAS cement was monitored by microcalorimetry and the corresponding kinetic parameters were analyzed. The pore solution from AAS was collected and analyzed using the high pressure press method. The effects of Na2Cr2O4 on the hydration products of AAS cement were observed and compared using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The experimental results showed that the AAS hydration process was markedly affected by Na2Cr2O4 dosage. The setting time of AAS pastes was increased and the compressive strength of cement stones was reduced with increasing dosage of Na2Cr2O4. With the development of AAS hydration, the leaching concentration of Na2Cr2O4 gradually decreased. Na2Cr2O4 did not affect the dissolution of slag particles, but impeded the formation of C-S-H gel. The Cr6+ was immobilized chemically in the form of needle-like CaCrO4 particles formed by the chemical reaction between Na2Cr2O4 and Ca2+ leaching from the slag.

Factors Influencing the Strength of Alkali-Activated Slag Cement

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.

Shrinkage-Compensating Alkali Activated Slag Cement Mortars for Crack Repair and Joint Grouting in Concretes

2014 ◽  
Vol 923 ◽  
pp. 134-137 ◽  
Author(s):  
Pavel Vasiljevich Krivenko ◽  
Grygorii Viktorovich Vozniuk ◽  
Anastasia Maksimovna Goncharova ◽  
Elena Sergeevna Kavalerova
Keyword(s):  
Cement Stone ◽  
Slag Cement ◽  
Alkali Activated Slag ◽  
Physico Chemical ◽  
Cement Mortars ◽  
Reasonable Cost ◽  
Crack Repair ◽  
Service Conditions ◽  
Activated Slag ◽  
Alkali Activated

Physico-chemical processes of hardening of a cement stone are accompanied with shrinkage is known to result in crack formation, loss of concrete structure integrity and finally, to shorter service life. These drawbacks make problems in using traditional portland cement based mortars for joint grouting and crack repair in concretes. Known-in-the-art solutions based on calcium aluminate cements are also not efficient due to high cost and instability of cement stone hydration products over time in various service conditions. Shrinkage-compensating alkali activated slag cement mortars are proposed to solve the problems connected with crack repair and joint grouting. They are simple in preparation and application and have a set of high physico-mechanical properties, excellent durability and reasonable cost.

Effect of geothermal waste on strength and microstructure of alkali-activated slag cement mortars

2003 ◽  
Vol 33 (10) ◽  
pp. 1567-1574 ◽  
Author(s):  
J.I Escalante-Garcı́a ◽  
A.V Gorokhovsky ◽  
G Mendoza ◽  
A.F Fuentes
Keyword(s):  
Slag Cement ◽  
Alkali Activated Slag ◽  
Cement Mortars ◽  
Activated Slag ◽  
Alkali Activated
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