Microcracking and strength development of alkali activated slag concrete

By F. Collins, J. Sanjayan. 2001

303 citations recorded by the source corpus.

Abstract Alkali activated slag concrete (AASC) is made by activating ground granulated blast furnace slag with alkalis without the use of any Portland cement. This study investigates the level of microcracking which occurs in AASC when subjected to various types of curing regimes. The corresponding compressive strength developments of AASC were monitored. The level of microcracking were measured using three different types of tests: (1) frequency and size of surface cracks using crack-detection microscope (2) water sorptivity tests measuring absorption of water by capillary attraction and (3) mercury intrusion porosimetry (MIP) tests which measured the pore size distribution of AASC and AAS pastes (AASPs). The results show that the lack of moist curing of AASC increased the level of microcracking measured using all three different tests mentioned above. The strength development of AASC is also significantly reduced by lack of moist curing.

Subfields: Civil and Structural Engineering

View Paper: https://www.semanticscholar.org/paper/87e326aed64c45dd76cd578a488792a4aadaf75d

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In Civil and Structural Engineering

Citations in the corpus

Durability assessment of alkali activated slag (AAS) concrete (2012, unknown): “Collins and Sanjayan have shown that AAS concrete display high shrinkage strains [42] and that improved curing can reduce microcracking [43].”
Use of waste glass in alkali activated cement mortar (2018, background): “When the AAC materials were cured under dry conditions, the formation of microcracks due to the high shrinkage would lead to a lower compressive strength [68].”
Alkali-activated binders: A review. Part 2. About materials and binders manufacture (2008, background): “Collins and Sanjayan [69,70] studied the activation of slag with powder waterglass, having reported lower strength for air curing without any kind of isolation (fc = 33 MPa) when compared to air curing with isolation (fc = 50 MPa) or water curing (fc = 55 MPa).”
Comparison of alkali and silica sources in one-part alkali-activated blast furnace slag mortar (2018, background): “There are more microcracks present in the SS1 binder, which might be an indication water escaping during curing; a longer curing at higher relative humidity might decrease the tendency for microcracks to appear (Collins and Sanjayan, 2001).”
Effect of silicate modulus and metakaolin incorporation on the carbonation of alkali silicate-activated slags (2010, background): “This phenomenon contributes to the ingress of aggressive agents, increasing susceptibility to degradation by transportmechanisms, and also leads to the formation of microcracks in the material, reducing its mechanical performance [20].”