Recent advances in understanding the role of supplementary cementitious materials in concrete

Nano reinforced cement and concrete composites and new perspective from graphene oxide

Beneficial role of nanosilica in cement based materials – A review

https://pure.tue.nl/ws/files/3881873/448899096909189.pdf

Effect of nano-silica on the hydration and microstructure development of Ultra-High Performance Concrete (UHPC) with a low binder amount

Influence of nano-silica agglomeration on microstructure and properties of the hardened cement-based materials

Influence of nano-silica agglomeration on fresh properties of cement pastes

The invention discloses a CRTS II type slab ballastless track cement asphalt (CA) mortar. The mortar is prepared by mixing cement, fine sand, expanding agent, aluminium powder, water, polycarboxylic water-reducing agent, emulsified asphalt, silica sol and defoaming agent. The raw materials contain the following components in parts by weight: 40-55 parts of cement, 3-7 parts of expanding agent, 0.00275-0.005 part of aluminium powder, 38-57 parts of fine sand, 0.8-1.1 parts of polycarboxylic water-reducing agent, 1.0-2.0 parts of silica sol, 0.0038-0.0072 part of defoaming agent, 13.0-15.7 parts of water, 13.9-16.9 parts of emulsified asphalt and 0-0.051 part of air entraining agent. In the preparation of the CRTS II type slab ballastless track CA mortar, by adding nanometer silica sol which only accounts for 1.0-2.0% of the total dosage of dry powder and is used as the nanometer thickener of the CA mortar, the rheological behavior of the CA mortar can be adjusted effectively, the layering and separation of the CA mortar can be prevented and the expansion stability of the CA mortar can be increased.

CRTS II type slab ballastless track cement asphalt (CA) mortar

Effect of nano-silica agglomeration on the hydration and hardening of cement was investigated by using precipitated silica(PS) with much larger agglomerates and nano-silica(NS) powder with much smaller ones as additives.The results reveal that the PS exhibits a higher pozzolanic reactivity at early ages and a better accelerating effect on the cement hydration though it possesses some larger agglomerates and a little lower pozzolanic reactivity at late ages rather than NS.The observation by scanning electron microscopy indicates that the cementitious property of the pozzolanic C-S-H gels from the agglomerates was limited.There even existed an interfacial transition zone between the reacted agglomerates and bulk hardened cement paste(HCP).The MIP results show that the NS addition can reduce the capillary and the gel pore of the HCP in the range of 20 nm-10 μm more effectively,compared to the PS addition.It is suggested that the effect of nano-silica addition on the microstructure improvement of the HCP could be resulted from the filling and water adsorbing effects of the agglomerates in the powder rather than the seeding effect.

Xiangfei Du

Papers

Influence of nano-silica agglomeration on microstructure and properties of the hardened cement-based materials

Influence of nano-silica agglomeration on fresh properties of cement pastes

CRTS II type slab ballastless track cement asphalt (CA) mortar

Effect of Nano-Silica Agglomeration on Hydration and Hardening of Cement