Journal
MATERIALS
Volume 16, Issue 19, Pages -Publisher
MDPI
DOI: 10.3390/ma16196514
Keywords
nanomaterials; polycarboxylate superplasticizer; diutan gum; low-density slurry; rheological properties; hydration kinetics
Ask authors/readers for more resources
Nanomaterials, such as Nano-SiO2 and gamma-nano-Al2O3, can enhance the rheology of cement slurry, while alpha-nano-Al2O3 and nano-TiO2 tend to reduce it. All nanomaterials can accelerate the early hydration of cement, with gamma-nano-Al2O3 having the strongest influence and Nano-SiO2 being the only one that further increases the long-term hydration heat release.
Nanomaterials have great potential to influence the properties of cement-based materials due to their small particle size and large specific surface area. The influences of Nano-SiO2 (NS), gamma-nano-Al2O3 (GNA), alpha-nano-Al2O3 (ANA), and nano-TiO2 (NT) on the rheology and hydration kinetics of class G cement at 30(degrees)C were investigated in this study. The nanomaterials were added in dry powder form at dosages of 1, 2, 3, 5, and 7% by weight of cement (bwoc), and their dispersion was accomplished using polycarboxylate superplasticizer (PCE) at a dosage of 1.6% bwoc. PCE provides a uniform dispersion of nanoparticles in the cement matrix, enhancing the efficiency of nanomaterials. The w/c ratio varied between 0.718 and 0.78 to form a constant-density slurry of 1.65 g/cm(3). Our test results showed that NS and GNA caused significant increases in the rheology of the cement slurry, with this effect increasing with dosage, while ANA and NT tended to reduce the rheology of the slurry. Compared to a well-suspended and well-dispersed cement slurry generated by the use of PCE and diutan gum, all nanomaterials can accelerate early hydration by reducing the induction time, with GNA having the strongest influence, while NS was the only nanomaterial that further increased the long-term hydration heat release at 7 days. The stronger effect of NS and GNA on the cement slurry properties can be attributed to their higher chemical reactivity. The dosage effect on total hydration extent was relatively strong for ANA, NT, and NS from 3% to 5% but weak for GNA in the range from 3% to 7%.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available