Optimization of Clay Addition for the Enhancement of Pozzolanic Reaction in Nano-modified Cement Paste

Effect of nanosilica and montmorillonite nanoclay particles on cement hydration and microstructure

“…Montmorillonite particles are naturaly agglomerated inorganic, hydrophilic nanoparticles, and they are considered incompatible to be added directly in cement formulations because the clay will swell in presence of water. 53 For this reason, significant research has been dedicated to the modification of the clay in an organophilic material, compatible with cement, which is the case if the modifier is organic. The clay is then said to be organomodified [e.g.…”

“…A number of different modifiers/surfactants have been utilised in the published studies. For example, Birgisson and Dham 53 used organic ammonium chloride (also known as Cloisite Na + or sodium MMT) and concluded that the amount of modifier/surfactant must be carefully chosen with the use of zeta potential, by which the electrostatic repulsion between near and similarly charged particles in a dispersion can be determined. If the zeta potential is high, the dispersion is considered stable, i.e.…”

“…The introduction of nanoparticles in cement matrixes affects hydration, strength, durability and microstructure in a number of ways. An overview of the various roles that the nanoparticles may develop within the cement paste is briefly presented below and analytically discussed in the following sections: nanofillers, reducing the nanoporosity within the hydrated paste and extending the concept of particle packing 49–51 nanoreinforcements, increasing the tensile and flexural strength and consistence of the paste especially the sheet/platelet like nanoparticles 40,47,52 catalysts due to their high surface area 34,53,54 nucleation sites for the reactions due to their high specific surface area and the unsaturated bonds on the surface of the particles 52,55 highly reactive pozzolanas, consuming Ca(OH) 2 to produce additional C–S–H 47,51,56–58 counter balance against high amounts of supplementary cementitious materials (such as reduction in the early strength gain with high amounts of FA or need for superplasticisers with large quantities of μS). 49 Some of the nanoparticles more extensively researched in the cement industry are nanotitanium dioxide, 59 nano-Fe 2 O 3 , 45 nanoalumina (nano-Al 2 O 3 ), 60 nanosilica (nS), 51,54,57,61 nCs, 41,47,62,63 nano-LS (nano-CaCO 3 ) 64,65 and others.…”

Natural Hydraulic Lime Mortars for Hot-Humid Climates: Effects of Oyster Shells as Seeding Compound

“…Mix design and specification are done to achieve better HL mortar performance. Seeding microstructures has long been acknowledged as a technique for enhancing microstructures or accelerating phase formation [9]. Seeding is the addition of hydration products (seeds) during the mixing stage (or to a dry mix) to induce better mortar products [10].…”