FEA modelling of fracture toughness of steel fibre-reinforced geopolymer composites

• Fracture toughness of steel fibre-reinforced aluminosilicate geopolymers was modelled.
• Steel fibres were randomly distributed in the geopolymer matrix.
• Finite element method was used to predict fracture toughness of geopolymers.
• Effects of mixture proportions and curing condition on fracture toughness were studied.

In this study, fracture toughness of steel fibre-reinforced aluminosilicate geopolymers is investigated experimentally and is modelled by explicit finite element method. Nine geopolymeric pastes with various alkali activators to fly ash weight ratios, sodium hydroxide (NaOH) to sodium silicate weight ratios, NaOH concentrations and curing temperatures were prepared and their fracture toughness was measured by pre-notched three point bending specimens. All samples were then reinforced by substituting of 2, 3 and 5 vol.% of geopolymeric pastes by steel fibres with diameter and length of 0.5 and 30 mm respectively. The effects of four different parameters on experimental and predicted fracture toughness were probed. Results indicated that NaOH to sodium silicate and alkali activator to fly ash weight ratios do not cause any deviation between experimental and predicted results. On the other hand, NaOH concentration and curing temperature were the most significant parameters that caused deviation of predicted results from experimental ones. Generally, it is possible to use the proposed modelling procedure to predict fracture toughness of steel-fibre reinforced geopolymers with a reasonable approximation.

The procedure of modelling and analysing of the fracture toughness of fibre-reinforced geopolymer composites obtained by finite element analysis.Figure optionsDownload as PowerPoint slide