Fly-ash based geopolymer mortar for high-temperature application – Effect of slag addition

Geopolymer materials have been gaining ground in the civil construction sector not only for having superior physical properties when compared to conventional cement, but also for being less harmful to the environment, since the synthesis of the geopolymer does not release toxic gases or require high energy costs. On the other hand, geopolymer materials like cementitious matrices have low flexural strength and have fragile breakage. To overcome these deficiencies, the insertion of fibers in geopolymeric matrices has been evaluated as a solution. Although most research on this practice focuses on the use of synthetic fibers, the use of natural fibers has been growing and brings as an advantage the possibility of producing an even more ecological material, satisfying the need to create eco-friendly materials that exists today in society. Thus, this paper aimed to, through the evaluation of research available in the literature, understand the behavior of fibers in geopolymer matrices, identify similarities and differences between the performance of geopolymer composites reinforced with natural and synthetic fibers and, understanding that it is possible, point out ways to optimize the performance of these composites.

https://www.mdpi.com/2073-4360/13/15/2493/pdf

Natural Fibers as an Alternative to Synthetic Fibers in Reinforcement of Geopolymer Matrices: A Comparative Review.

Brazil is a country of continental dimensions and characteristics with enormous biodiversity of fauna and flora which confers a prominent role in the sector of extraction of agricultural products. However, one of the current challenges is the increasing amounts of agricultural solid wastes generated by different local production processes which end up resulting in enormous environmental liabilities. One way to effectively manage these agro-industrial wastes is by their application in the development of alternative cementitious materials such as mortars and concretes. Thus, the objective of this paper is to discuss the recent advances, challenges and future perspective of the application of some solid agro-industrial wastes generated specifically in Brazil and some other parts of the world in cementitious materials. The application of wastes from pineapple, sugar cane, açai, coconut and rice were explored and discussed. The discussion presented in this paper is anticipated to strongly contribute to the advancement of public policies that enable the real application of these wastes in the development of eco-friendly cementitious materials for civil construction. 

Possibilities for the application of agro-industrial wastes in cementitious materials: A brief review of the Brazilian perspective

Geopolymer concrete as green building materials: Recent applications, sustainable development and circular economy potentials.

Geopolymer concrete (GPC) is a new material in the construction industry, with different chemical compositions and reactions involved in a binding material. The pozzolanic materials (industrial waste like fly ash, ground granulated blast furnace slag (GGBFS), and rice husk ash), which contain high silica and alumina, work as binding materials in the mix. Geopolymer concrete is economical, low energy consumption, thermally stable, easily workable, eco-friendly, cementless, and durable. GPC reduces carbon footprints by using industrial solid waste like slag, fly ash, and rice husk ash. Around one tonne of carbon dioxide emissions produced one tonne of cement that directly polluted the environment and increased the world’s temperature by increasing greenhouse gas production. For sustainable construction, GPC reduces the use of cement and finds the alternative of cement for the material’s binding property. So, the geopolymer concrete is an alternative to Portland cement concrete and it is a potential material having large commercial value and for sustainable development in Indian construction industries. The comprehensive survey of the literature shows that geopolymer concrete is a perfect alternative to Portland cement concrete because it has better physical, mechanical, and durable properties. Geopolymer concrete is highly resistant to acid, sulphate, and salt attack. Geopolymer concrete plays a vital role in the construction industry through its use in bridge construction, high-rise buildings, highways, tunnels, dams, and hydraulic structures, because of its high performance. It can be concluded from the review that sustainable development is achieved by employing geopolymers in Indian construction industries, because it results in lower CO2 emissions, optimum utilization of natural resources, utilization of waste materials, is more cost-effective in long life infrastructure construction, and, socially, in financial benefits and employment generation.

https://www.mdpi.com/2073-4352/12/4/514/pdf

Ye Zheng

Papers

Eco-friendly geopolymer materials: A review of performance improvement, potential application and sustainability assessment