Geopolymers are generally appreciated for their good resistance against high temperatures. This paper compares the influence of thermal treatment with temperatures ranging from 200 to 1200 °C on mechanical properties and microstructure geopolymers based two different aluminosilicate precursors, metakaolin fly ash. Moreover, is also aimed at characterizing effect chamotte aggregate performance subjected Thermal leads a deterioration in strength geopolymer, whereas ash geopolymer gains upon...

Aluminosilicate materials can be transformed into very compact binding material by the process called alkaline activation. The paper presents results of activation fly ash and waste fine-grained brick body. Prepared geopolymers were tested for compressive flexural strengths, bulk density, microstructure was examined means SEM. investigated parameters showed differences in relation to ratio binder.

Fly ash geopolymer is amorphous aluminosilicate material which considered as alternative to Portland cement concrete. One of the limiting factors its utilization an increased shrinkage and related deterioration fracture properties. This paper reports on a study application multi-walled carbon nanotubes (MWCNTs) improve properties fly geopolymer. The amount MWCNTs added varied in range 0.05–0.2% mass ash. Mechanical were determined via evaluation three-point bending tests. Specimen response...

The electrical properties of concrete are gaining their importance for the application in building construction. In this study, graphite powder was added to alkali-activated slag mortar as an electrically conductive filler order enhance mortar’s properties. amount ranged from 1% 30% mass. effect on resistivity, capacitance, mechanical properties, and microstructure composite investigated. Selected mixtures were then used testing self-sensing under compressive loading. results show that...

The study investigates the impact of quaternary ammonium and pyridinium salts on rheological properties metakaolin-based geopolymer pastes, with a focus their application in 3D printing technology experimental results demonstrated that addition these increased both plastic viscosity yield stress mixtures, effect intensifying higher concentrations longer aliphatic chains. coefficient consistency derived from Herschel-Bulkley model 1.78 up to 3.83 Pa·s n rose 3.4 31.8 Pa. also observed shift...

Aluminosilicate binders, such as Portland cement or geopolymers, are generally considered electrical insulators. In order to decrease their resistance, electrically conductive fillers added. This brings new application possibilities, the self-sensing and self-monitoring of smart structures. this study, three different aluminosilicate composites with same amount fine graphite filler (6% respect basic raw material) were tested for resistance- capacitance-based properties. two geopolymer...

Alkali-activated slag belongs to prospective materials in the field of fire protection because it exhibits remarkable high-temperature resistance. In this article, specific heat capacity, thermal diffusivity, and conductivity an alkali-activated with sand aggregates are studied as functions temperature up 1200 ° C. The experiments performed during material exposure high temperatures. irregularities observed on measured dependences capacity diffusivity discussed using results DTA X-ray...

By incorporation of nanotubes to the current composite materials, their properties can be significantly improved. Carbon act as filler, which minimizes air gaps content in matrix. The denser structure positively affects physical and mechanical whole composite. paper deals with alkali-activated materials (AAM) based on finely-ground granulated blast furnace slag modified by carbon nanotubes. Prismatic samples this type AAM were prepared addition 0.1 – 0.4 wt. % (with 0.1% step). change...

The development of smart materials is a basic prerequisite for the new technologies enabling continuous non-destructive diagnostic analysis building structures. Within this framework, piezoresistive behavior fly ash geopolymer with added carbon black under compression was studied. Prepared cubic specimens were doped 0.5, 1 and 2% embedded four copper electrodes. In order to obtain complex characterization during compressive loading, electrical resistivity, longitudinal strain acoustic...

Polyethylene glycol is a non-toxic water soluble polymer often used in many industrial applications. The aim of this paper to study the effect polyethylene with relative molecular weight ranging between 400–20000 on properties geopolymer mortars composed metakaolin and sodium silicate. was added amount 0.5 10% by mass metakaolin. After 28 days curing at ambient conditions, different tests were carried out: physico-chemical (density, porosity), mechanical (flexural compressive strength)...

This paper deals with durability design and comments on the assessment of reinforced concrete (RC) structures in relation to existing codes. Enhancement is provided by advanced approaches incorporating probabilistic simulations, mathematical models carbonation process concretes made from CEM I through V, reliability issue. presents practical software tools used for service life prediction, cover evaluation relevant levels. A partial verification using test results also presented.

Abstract Thermal diffusivity, specific heat capacity and linear thermal expansion coefficient of a lightweight composite with alkali‐activated aluminosilicate binder heat‐resistant aggregate mixture expanded vermiculite electrical porcelain are measured in wide temperature range. Experimental results show that the studied material has good prerequisites for high‐temperature applications. The apparent diffusivity at one‐sided heating is significantly lower than room temperature, decreases...

The interaction between POCl(3) or POBr(3) and pyridine DMAP has been reinvestigated to clarify the discrepancies previously published results concerning Lewis acidity of phosphoryl halides their behavior toward bases. obtained show that virtually does not react with pyridine, while it 4-(dimethylamino)pyridine (DMAP), even in SO(2) solution, yield an ionic compound [(DMAP)(2)PO(2)]Cl.3SO(2) (1.3SO(2)). Its recrystallization from acetonitrile gives [(DMAP)(2)PO(2)]Cl.CH(3)CN (1.CH(3)CN)....

Alkali-activated aluminosilicates (AAAs) with electrically conductive admixtures are promising competitors to the cement-based materials enhanced in same way.The electrical conductivity of these dramatically increases a sufficient amount admixtures, which broaden their possible applicability.Electrically optimized typically used self-heating, self-sensing or magnetic-shielding systems.However, an increase can negatively affect compressive flexural strength and lead porosity.Therefore, it is...