This study reports on the microstructure, compressive strength, and drying shrinkage of metakaolin (MK) based geopolymers produced by partially replacing MK by oil palm ash (OPA). The OPA was used as raw material producing different molar ratios of SiO₂/Al₂O₃ and CaO/SiO₂. The geopolymer samples were cured at 80°C for 1, 2, or 4 hours and kept at ambient temperature until testing. The compressi...

Geopolymers are inorganic polymers formed from the alkaline activation of amorphous alumino-silicate materials resulting in a three-dimensional polymeric network. As a class of materials, it is seen to have the potential of replacing ordinary Portland cement (OPC), which for more than a hundred years has been the binder of choice for structural and building applications. Geopolymers have emerge...

This paper presents the results of study on effect of various parameters on mechanical properties of fly ash-based geopolymer mortar with bottom ash as partial or full replacement for sand. Compressive strength of samples with 10% bottom ash (BA) was comparable to those with only sand. Further increase in bottom ash content decreased the compressive strength. However, the reverse tendency occur...

In this study the development of a metakaolin based geopolymeric mortar to be used as bonding matrix for external strengthening of reinforced concrete beams is reported. Four geopolymer formulations have been obtained by varying the composition of the activating solution in terms of SiO₂/Na₂O ratio. The obtained samples have been characterized from a structural, microstructural and mechanical p...

it has been shown that geopolymerization can transform a wide range of waste aluminosilicate materials into building materials with excellent chemical and physical properties such as fire and acid resistance. in this research work, geopolymerization of construction waste materials with different alkali-activators based on combinations of na2sio3 and naoh has been investigated. a number of syste...

Ternary clay-based composite material (TCC), composed of lime, clay and sand, and usually modified with sticky rice and other organic compounds as additives, was widely used historically in Chinese construction and buildings due to its high mechanical performance. In this study, to gain an insight into the micromechanical mechanism of this cementitious material, the nanomechanical properties an...

Geopolymer concrete mixes were cast using fly ash, kaolin, sodium hydroxide, potassium hydroxide, sodium silicate and aggregates. Portland cement concrete (M30) was used as a reference sample. The effect of silica fume, temperature (40 °C, 60 °C, 80 °C, 100 °C and 120 °C), sodium and potassium hydroxides and different superplasticizers on the compressive strength are reported [1]. Maximum stren...

The worldwide production of PCC fly ash is estimated at achieving 800 million tonnes per year in 2010 [1]. European Union regulations aim at developing new technologies focused on the recycling of these large amounts of PCC fly ash into added-value products. The synthesis of geopolymer binders may be a successful alternative, giving rise to low-cost and environmentally friendly materials with c...

ADRIANA BALAN1, SIMONA STOLERIU1*, SORIN ANDRIAN1, ANDREI VICTOR SANDU2,3, CARMEN SAVIN1 1 „Grigore T. Popa” University of Medicine and Pharmacy of Iasi, Faculty of Dental Medicine, 16 Universitatii Str., 700115, Iaoi, Romania 2 „Gheorghe Asachi” Technical University of Iasi, Faculty of Materials Science and Engineering, 53A D. Mangeron Blvd., 700050, Iasi, Romania 3 Center of Excellence Geopol...

Metakaolin based geopolymers are presented in many studies as an alternative to normal Portland cement. Previous studies have focused on their chemical and mechanical properties, their microstructures and their potential uses, but very few on their rheological behaviour. Our work highlights the main differences that exist between geopolymer and Portland cement. These materials behave as Newtoni...