27 KB954 KB23 KB200020242013Blečić, DragoljubNikolić, IrenaRadmilović, VelimirRadmilović, VukZejak, Radomirštevilka:4letnik:47str. 535-540COBISSID:1007530ISSN:1580-2949URN:URN:NBN:SI:doc-RXUCC9O9enInštitut za kovinske materiale in tehnologijeMateriali in tehnologijecompressive strengthflexural strengthfly ash mortargeopolimerizacijageopolymerizationleteči pepelmaltatlačna trdnostupogibna trdnostYoungov modulYoung's modulusMechanical and microstructural properties of the fly-ash-based geopolymer paste and mortar| Mehanske in mikrostrukturne lastnosti geopolimernih veziv in malt iz letečega pepela|In this paper we have investigated the influence of synthesis parameters on the mechanical properties of the fly-ash-based geopolymer paste and mortars. Moreover, the influence of an addition of limestone sand on the microstructure of fly-ash-based geopolymers was investigated as well. An addition of limestone sand increased the compressive strength of the fly-ash-based geopolymer mortar, in comparison to the strength of the geopolymer paste, by changing the composition of the gel phase in the geopolymer structure and with the physical strengthening due to the presence of well connected grains of the sand. The results have shown that the compressive strength and Young's modulus of elasticity of the fly-ash-based geopolymer mortar are correlated. The values of these parameters increase as the alkali and silicate dosages increase. At one point, they reach the maximum values and then start to decrease. On the other hand, the parameters that considerably increase the compressive strength slightly decrease the flexural strength of the geopolymer mortarČlanek obravnava raziskavo vplivov parametrov sinteze na mehanske lastnosti geopolimernih veziv in malt iz letečega pepela. Preiskovan je bil tudi vpliv dodatka peska iz apnenca na mikrostrukturo geopolimera iz letečega pepela. Dodatek peska iz apnenca je povečal tlačno trdnost geopolimerne malte iz letečega pepela v primerjavi s trdnostjo geopolimernega veziva s spreminjanjem sestave želirne faze v strukturi geopolimera in s fizikalnim utrjevanjem zaradi prisotnosti dobro povezanih zrn peska. Rezultati so pokazali pri geopolimeru iz letečega pepela povezavo med tlačno trdnostjo in Youngovim modulom elastičnosti. Vrednosti teh parametrov naraščajo z naraščanjem dodatkov silikatov in alkalij. V določeni točki dosežejo največjo vrednost in se potem začnejo zmanjševati. Po drugi strani pa parametri, ki občutno povečajo tlačno trdnost, rahlo zmanjšajo upogibno trdnost geopolimerne malteTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije