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

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.

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Studies of the corrosion of mild steel in alkali-activated slag cement mortars with sodium chloride admixtures by a galvanostatic pulse method

Corrosion Science ◽

10.1016/j.corsci.2005.05.035 ◽

2005 ◽

Vol 47 (12) ◽

pp. 3097-3110 ◽

Cited By ~ 28

Author(s):

M. Holloway ◽

J.M. Sykes

Keyword(s):

Sodium Chloride ◽

Mild Steel ◽

Pulse Method ◽

Slag Cement ◽

Alkali Activated Slag ◽

Cement Mortars ◽

Activated Slag ◽

Alkali Activated

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.712-715.905 ◽

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).

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

Frontiers in Materials ◽

10.3389/fmats.2021.754463 ◽

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.

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