scholarly journals A Review on Durability of Alkali-activated System from Sustainable Construction Materials to Infrastructures

Author(s):  
Wengui Li ◽  
◽  
Zhuo Tang ◽  
Vivian W. Y. Tam ◽  
XinYu Zhao ◽  
...  
2021 ◽  
Vol 11 (11) ◽  
pp. 4754
Author(s):  
Assia Aboubakar Mahamat ◽  
Moussa Mahamat Boukar ◽  
Nurudeen Mahmud Ibrahim ◽  
Tido Tiwa Stanislas ◽  
Numfor Linda Bih ◽  
...  

Earth-based materials have shown promise in the development of ecofriendly and sustainable construction materials. However, their unconventional usage in the construction field makes the estimation of their properties difficult and inaccurate. Often, the determination of their properties is conducted based on a conventional materials procedure. Hence, there is inaccuracy in understanding the properties of the unconventional materials. To obtain more accurate properties, a support vector machine (SVM), artificial neural network (ANN) and linear regression (LR) were used to predict the compressive strength of the alkali-activated termite soil. In this study, factors such as activator concentration, Si/Al, initial curing temperature, water absorption, weight and curing regime were used as input parameters due to their significant effect in the compressive strength. The experimental results depict that SVM outperforms ANN and LR in terms of R2 score and root mean square error (RMSE).


2018 ◽  
Vol 16 (3) ◽  
pp. 186-202 ◽  
Author(s):  
Luigi Coppola ◽  
Tiziano Bellezze ◽  
Alberto Belli ◽  
Maria Chiara Bignozzi ◽  
Fabio Bolzoni ◽  
...  

This review presents “a state of the art” report on sustainability in construction materials. The authors propose different solutions to make the concrete industry more environmentally friendly in order to reduce greenhouse gases emissions and consumption of non-renewable resources. Part 1—the present paper—focuses on the use of binders alternative to Portland cement, including sulfoaluminate cements, alkali-activated materials, and geopolymers. Part 2 will be dedicated to traditional Portland-free binders and waste management and recycling in mortar and concrete production.


2021 ◽  
Vol 13 (17) ◽  
pp. 9938
Author(s):  
Nuno Cristelo ◽  
Fernando Castro ◽  
Tiago Miranda ◽  
Zahra Abdollahnejad ◽  
Ana Fernández-Jiménez

The sustainability of resources is becoming a worldwide concern, including construction and building materials, especially with the alarming increase rate in global population. Alternative solutions to ordinary Portland cement (OPC) as a concrete binder are being studied, namely the so-called alkali-activated cements (AAC). These are less harmful to the environment, as lower CO2 emissions are associated with their fabrication, and their mechanical properties can be similar to those of the OPC. The aim of developing alkali-activated materials (AAM) is the maximization of the incorporated recycled materials, which minimises the CO2 emissions and cost, while also achieving acceptable properties for construction applications. Therefore, various efforts are being made to produce sustainable construction materials based on different sources and raw materials. Recently, significant attention has been raised from the by-products of the steelmaking industry, mostly due to their widespread availability. In this paper, ladle slag (LS) resulting from steelmaking operations was studied as the main precursor to produce AAC, combined with phosphating bath sludge—or phosphate sludge (PS)—and aluminium anodising sludge (AS), two by-products of the surface treatment of metals, in replacement rates of 10 and 20 wt.%. The precursors were activated by two different alkaline solutions: a combination of commercial sodium hydroxide and sodium silicate (COM), and a disposed solution from the cleaning of aluminium extrusion steel dies (CLE). This study assesses the influence of these by-products from the steelmaking industry (PS, AS and CLE) on the performance of the alkali-activated LS, and specifically on its fresh and hardened state properties, including rheology, heat of hydration, compressive strength and microstructure and mineralogy (X-ray diffraction, scanning electron microscopy coupled with energy dispersive spectroscopy and Fourier transform infra-red. The results showed that the CLE had no negative impact on the strength of the AAM incorporating PS or/and AS, while increasing the strength of the LS alone by 2×. Additionally, regardless of the precursor combination, the use of a commercial activator (COM) led to more fluid pastes, compared with the CLE.


2018 ◽  
Vol 247 ◽  
pp. 00054
Author(s):  
Michał Łach ◽  
Dariusz Mierzwiński ◽  
Kinga Korniejenko ◽  
Artur Stanek ◽  
Janusz Mikuła

Growing environmental awareness and importance of development of sustainable construction materials for decreasing environmental impact of construction industry are main motivators to research work on new, innovative materials’ solutions. The most promise alternative solutions are technologies based on alkali-activated. This process allows to obtain the fire-resistant materials. However, it is a rather complex process, when using waste materials. Nevertheless, waste-based Alkali Activated Materials AAMs can be optimized and tailored to desired applications. The main objective of the article is to analyse the possibilities of using calcium clay from the city called Raciszyn, Poland for the AAMs manufacturing and the properties of the obtained material, including thermal resistance. The results show that new materials have good mechanical properties at elevated temperatures. The materials were tested at 800°C, depending on the used alkaline activator, they were characterized by bending strength in the range: 2.7-6.2 MPa. A permanent change in dimensions due to heating was also determined. Due to the very high fire resistance, materials referred to as AAMs, also produced from waste such as calcium clay, can find a variety of applications in construction and where it is necessary to ensure the passive fire protection.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2911
Author(s):  
Margarida Gonçalves ◽  
Inês Silveirinha Vilarinho ◽  
Marinélia Capela ◽  
Ana Caetano ◽  
Rui Miguel Novais ◽  
...  

Ordinary Portland Cement is the most widely used binder in the construction sector; however, a very high carbon footprint is associated with its production process. Consequently, more sustainable alternative construction materials are being investigated, namely, one-part alkali activated materials (AAMs). In this work, waste-based one-part AAMs binders were developed using only a blast furnace slag, as the solid precursor, and sodium metasilicate, as the solid activator. For the first time, mortars in which the commercial sand was replaced by two exhausted sands from biomass boilers (CA and CT) were developed. Firstly, the characterization of the slag and sands (aggregates) was performed. After, the AAMs fresh and hardened state properties were evaluated, being the characterization complemented by FTIR and microstructural analysis. The binder and the mortars prepared with commercial sand presented high compressive strength values after 28 days of curing-56 MPa and 79 MPa, respectively. The mortars developed with exhausted sands exhibit outstanding compressive strength values, 86 and 70 MPa for CT and CA, respectively, and the other material’s properties were not affected. Consequently, this work proved that high compressive strength waste-based one-part AAMs mortars can be produced and that it is feasible to use another waste as aggregate in the mortar’s formulations: the exhausted sands from biomass boilers.


2014 ◽  
Vol 66 (12) ◽  
pp. 618-626 ◽  
Author(s):  
Luís Filipe Brandão Ferreira ◽  
Hugo Sérgio Sousa Costa ◽  
Inês Isabel Antunes Barata ◽  
Eduardo Nuno Brito Santos Júlio ◽  
Paulo Maranha Nunes Tiago ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document