Geopolymer recycled aggregate concrete: From experiments to empirical models
Journal article, 2021

Ordinary cement concrete is a popular material with numerous advantages when compared to other construction materials; however, ordinary concrete is also criticized from the public point of view due to the CO2 emission (during the cement manufacture) and the consumption of natural resources (for the aggregates). In the context of sustainable development and circular econ-omy, the recycling of materials and the use of alternative binders which have less environmental impacts than cement are challenges for the construction sector. This paper presents a study on non-conventional concrete using recycled aggregates and alkali-activated binder. The specimens were prepared from low calcium fly ash (FA, an industrial by-product), sodium silicate solution, sodium hydroxide solution, fine aggregate from river sand, and recycled coarse aggregate. First, influences of different factors were investigated: the ratio between alkaline activated solution (AAS) and FA, and the curing temperature and the lignosulfonate superplasticizer. The interfacial transition zone of geopolymer recycled aggregate concrete (GRAC) was evaluated by microscopic analyses. Then, two empirical models, which are the modified versions of Feret’s and De Larrard’s models, respec-tively, for cement concretes, were investigated for the prediction of GRAC compressive strength; the parameters of these models were identified. The results showed the positive behaviour of GRAC investigated and the relevancy of the models proposed.

Recycled aggregate concrete (RAC)

Fly ash

Modified Feret’s model

Geopolymer

De Larrard’s model

Author

Hoai Bao Le

Mien Tay Construction University

Ton Duc Thang University

Quoc Bao Bui

Ton Duc Thang University

Luping Tang

Chalmers, Architecture and Civil Engineering, Building Technology

Materials

19961944 (eISSN)

Vol. 14 5 1-22 1180

Subject Categories

Applied Mechanics

Construction Management

Environmental Management

DOI

10.3390/ma14051180

More information

Latest update

4/6/2022 5