Inorganic polymers from alkali activation of metakaolin: Effect of setting and curing on structure

Reaction kinetics, gel character and strength of ambient temperature cured alkali activated slag–fly ash blends

“…The absorption band at around 870 cm À1 that is associated with vibrations of SiAO terminal structures is observed in samples with activator modulus of 1.8 and 1.4 (mix A and C), and it is independent of slag/fly ash mass ratios, showing again that the reaction products are a short range C-A-S-H enriched type gels [60]. When decreasing the activator modulus to 1.0 (mix E), this absorption band disappears and a new band at around 880 cm À1 that represents the SiAOH bending vibration appears [61,62], this is probably due to the reduced extra silica from activator and increased alkalinity caused by the decreased activator modulus. Thus lowering the activator modulus to a certain level will lead to the structural changes to some degree.…”

Geopolymer/PEG Hybrid Materials Synthesis and Investigation of the Polymer Influence on Microstructure and Mechanical Behavior

“…They have been mainly proposed as more environmentally friendly substitutes of Portland cement 5,6 because of the greater energy efficiency of their manufacturing process and the substantial reduction in CO 2 emissions 7,8 . Following the particular aluminosilicate precursor 3 , the stoichiometric ratio of Si/Al [1,9] , alkali hydroxide and water content 10,11 as well as the reaction temperature, pressure 3 , activation, setting and curing procedures 11,12 , geopolymers can exhibit a wide variety of properties, such as high compressive strength, low shrinkage, fast or slow setting, acid and fire resistance, low thermal conductivity, long term durability and thermal stability. Thanks to these characteristics, geopolymers have a wide range of potential applications in construction building, in the biomedical field, in cultural heritage maintenance and renovation and immobilization of heavy metals and nuclear waste management.…”

Investigation on the Effect of Slag and Limestone Powder Addition in Alkali Activated Metakaolin

“…The absorption bands around 450 cm -1 represent the internal deformation vibrations of Si-O bonds [19], which is mainly influenced by the nature of raw materials and thus no remarkable changes take place. The absorption band around 1470 cm -1 appeared only in the samples with large slag content, it represents the asymmetric stretching mode of the O-C-O groups [20], which means the carbonation has taken place to some extent, it may also indicate that samples with higher slag content are more vulnerable to carbonation, but still more study are needed to confirm this conclusion. The infrared spectra of samples containing limestone powder are not shown because there are no significant changes in the major absorption bands when limestone powder was added, which indicates that the incorporation of limestone powder has no influence on the reaction products and it only works as an non-reactive filler in alkali activated system.…”