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On the chemo-mechanical evolution process of high-volume slag cement paste
https://orcid.org/0000-0003-4668-1553
https://orcid.org/0000-0003-4175-2877
https://orcid.org/0000-0003-3399-9036
https://orcid.org/0000-0003-1299-1449
Highlights The combined analysis of phase assemblage, microstructure, and micromechanical properties. A two-scale micromechanical model to predict the effective elastic modulus. The existence of interface between unhydrated slag grains and hydrated cement matrix.
Abstract This study investigated the evolution process of high-volume slag cement (HVSC) paste from a chemo-mechanical standpoint. HVSC specimens with a 70 w.t. % slag replacement rate were studied at various ages. Evolution of phase assemblage, microstructure development, and micromechanical properties were analyzed using TGA/XRD/MIP/SEM-EDS and nano-/micro-indentation techniques. A two-scale micromechanical model was built to predict the effective elastic modulus based on the nanoindentation results. Key findings include: 1) Between 7 and 28 days, the formation of calcium silicate hydrate (C-S-H) gel phase improves the effective elastic modulus by filling capillary pores; 2) From 28 to 90 days, the phase assemblage and microstructure remain stable, with a transition from low-density to high-density C-S-H; 3) Between 90 days and 2 years, slag rims produced by slag grains result in increased elastic modulus; 4) The two-scale micromechanical model, combined with nanoindentation data, accurately predicts the effective modulus of HVSC composites, although the unhydrated slag grains-hydrated cement matrix interface may cause an overestimation at an early age. With longer curing time, this interface disappears owing to the continuous hydration of large slag particles and therefore a good match is found between the modelling and experimental results.
On the chemo-mechanical evolution process of high-volume slag cement paste
https://orcid.org/0000-0003-4668-1553
https://orcid.org/0000-0003-4175-2877
https://orcid.org/0000-0003-3399-9036
https://orcid.org/0000-0003-1299-1449
Highlights The combined analysis of phase assemblage, microstructure, and micromechanical properties. A two-scale micromechanical model to predict the effective elastic modulus. The existence of interface between unhydrated slag grains and hydrated cement matrix.
Abstract This study investigated the evolution process of high-volume slag cement (HVSC) paste from a chemo-mechanical standpoint. HVSC specimens with a 70 w.t. % slag replacement rate were studied at various ages. Evolution of phase assemblage, microstructure development, and micromechanical properties were analyzed using TGA/XRD/MIP/SEM-EDS and nano-/micro-indentation techniques. A two-scale micromechanical model was built to predict the effective elastic modulus based on the nanoindentation results. Key findings include: 1) Between 7 and 28 days, the formation of calcium silicate hydrate (C-S-H) gel phase improves the effective elastic modulus by filling capillary pores; 2) From 28 to 90 days, the phase assemblage and microstructure remain stable, with a transition from low-density to high-density C-S-H; 3) Between 90 days and 2 years, slag rims produced by slag grains result in increased elastic modulus; 4) The two-scale micromechanical model, combined with nanoindentation data, accurately predicts the effective modulus of HVSC composites, although the unhydrated slag grains-hydrated cement matrix interface may cause an overestimation at an early age. With longer curing time, this interface disappears owing to the continuous hydration of large slag particles and therefore a good match is found between the modelling and experimental results.
On the chemo-mechanical evolution process of high-volume slag cement paste
https://orcid.org/0000-0003-4668-1553
https://orcid.org/0000-0003-4175-2877
https://orcid.org/0000-0003-3399-9036
https://orcid.org/0000-0003-1299-1449
Highlights The combined analysis of phase assemblage, microstructure, and micromechanical properties. A two-scale micromechanical model to predict the effective elastic modulus. The existence of interface between unhydrated slag grains and hydrated cement matrix.
Abstract This study investigated the evolution process of high-volume slag cement (HVSC) paste from a chemo-mechanical standpoint. HVSC specimens with a 70 w.t. % slag replacement rate were studied at various ages. Evolution of phase assemblage, microstructure development, and micromechanical properties were analyzed using TGA/XRD/MIP/SEM-EDS and nano-/micro-indentation techniques. A two-scale micromechanical model was built to predict the effective elastic modulus based on the nanoindentation results. Key findings include: 1) Between 7 and 28 days, the formation of calcium silicate hydrate (C-S-H) gel phase improves the effective elastic modulus by filling capillary pores; 2) From 28 to 90 days, the phase assemblage and microstructure remain stable, with a transition from low-density to high-density C-S-H; 3) Between 90 days and 2 years, slag rims produced by slag grains result in increased elastic modulus; 4) The two-scale micromechanical model, combined with nanoindentation data, accurately predicts the effective modulus of HVSC composites, although the unhydrated slag grains-hydrated cement matrix interface may cause an overestimation at an early age. With longer curing time, this interface disappears owing to the continuous hydration of large slag particles and therefore a good match is found between the modelling and experimental results.
On the chemo-mechanical evolution process of high-volume slag cement paste
Liang, Minfei (author) / Zhang, Yu (author) / He, Shan (author) / Chen, Yu (author) / Schlangen, Erik (author) / Šavija, Branko (author)
2023-08-06
Article (Journal)
Electronic Resource
English
Chemo-mechanical characterization of a low-pH model cement paste in magnesium bearing environment
| Elsevier | 2024