Abstract In recent years, the addition of nanometer materials to concrete materials has attracted a group of increasing number of scholars’ research interests, and nano-SiO2 is one of the research hotspots. In this paper, we briefly introduce the influence of nano-SiO2 on setting time, slump, shrinkage, durability and mechanical properties of concrete. In addition, this review also includes the microstructure measured by scanning electron microscope (SEM) and the content of various hydration products obtained by X-ray diffraction (XRD). The result shows that the setting time of nano-SiO2 concrete is shortened, the slump is reduced and the shrinkage is improved owing to the high activity and nucleation of nano-SiO2. The improvement effect of nano-SiO2 on concrete is remarkable, especially in the aspect of enhancing the durability of concrete. It should be noted that nano-SiO2 shows limited improvement in the mechanical properties of concrete. In the end, this literature summary explains the macro performance of nano-silica modified concrete through microstructure.

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The effect of nano-SiO2 on concrete properties: a review

Circular economy and durability in geopolymers ceramics pieces obtained from glass polishing waste

Thermal performance of the building envelope integrated with phase change material for thermal energy storage: an updated review

Effect of nanomaterials inclusion on sustainability of cement-based concretes: A comprehensive review

Geopolymers are novel cementitious materials that have the potential to replace conventional Portland cement composites completely. The production of geopolymer composites has a lower carbon footprint and uses less energy than the production of Portland cement. Recently efforts have been made to incorporate different types of nanoparticles (NPs) in geopolymer composites to enhance the properties of the composite with improved performances. Nanotechnology is one of the most active research areas with novel science and valuable applications that have gradually gained attention, especially during the last two decades. Many studies have been undertaken to date in order to understand better the impacts of NPs addition on the fresh, physical, mechanical, durability, and microstructure properties of geopolymer composites. In the current comprehensive review paper, the effects of different NP types on the most essential fresh, mechanical, durability, and microstructure characteristics of geopolymer paste, mortar, and concrete composites were reviewed, analyzed, and discussed in detail. In this regard, more than 280 published papers were used to create an extensive database that includes the main features of geopolymer composites modified with different NPs. In addition, the main mechanisms behind the influence of different NP types on the properties of geopolymer composites were examined. Past progress, recent drifts, current obstacles, and the benefits and drawbacks of these geopolymer composites enhanced with NPs were also highlighted. Based on the findings of this study, the addition of NPs has a promising future for developing high-performance geopolymer composites that the construction industry can efficiently implement due to significant improvements in strength, durability, microstructure by providing additional C–S–H, N-A-S-H, and C-A-S-H gels as well as filling nano-pores in the geopolymer matrix. 

The role of nanomaterials in geopolymer concrete composites: A state-of-the-art review

Thermal conductivity of cement paste containing waste glass powder, metakaolin and limestone filler as supplementary cementitious material

Comparative study on the effects of nano-SiO2, nano-Fe2O3 and nano-NiO on hydration and microscopic properties of white cement

In order to explore the all-round influence of nano-SiO2 (NS) and nano-Al2O3 (NA) on cement-based materials, especially the small dosage and compound effect, the single and combined effects of NS and NA on mechanical and durability properties of cement-based materials were investigated. The contents of nanomaterials were 0.5%, 1.0%, 2.0% and 3.0% of the binder by weight, respectively. Results show that setting time could be shortened by introducing NS and NA except single-doped 2% and 3% NA and binary combination NS + NA at 3%. In addition, all hardened mortar systems with nanomaterials exhibited positive strength growth rate compared to control group. Especially, the compressive strength growth rates of mortars containing NS after 3 days were 10.5%, 27.09%, 26.78% and 42.13%, respectively, with the increase of NS content from 0.5% to 3%. In terms of durability, the charge passed, weight loss and capillary permeability coefficient decreased by adding small amount (0.5%) of NS and NA. And then the introducing of 0.5%NS + 0.5%NA powders at 1% reduced capillary permeability coefficient of concrete samples compared to that of 0.5%NS and 0.5%NA samples. Among all groups, the best performance was provided from NS at 1%, NA at 0.5%, and the binary combination NS + NA at 1%. Finally, the relationships between the drying rate/water absorption rate and time were given, which was conductive to study the moisture transport of nano-concrete.

Effects of nano-SiO2 and nano-Al2O3 on mechanical and durability properties of cement-based materials: A comparative study

Effect of low air pressure on the durability of concrete

Recently, it was observed that cracking on the surface of concrete bridge pillars is more significant in Chinese high-elevation regions, where the climatic character is low air pressure. Many regio...

Yuanbo Du

Papers

Thermal conductivity of cement paste containing waste glass powder, metakaolin and limestone filler as supplementary cementitious material

Comparative study on the effects of nano-SiO2, nano-Fe2O3 and nano-NiO on hydration and microscopic properties of white cement

Effects of nano-SiO2 and nano-Al2O3 on mechanical and durability properties of cement-based materials: A comparative study

Effect of low air pressure on the durability of concrete

Effect of low air pressure on mechanical properties and shrinkage of concrete