یک بررسی در مورد عملکرد ساختاری و مادی بتن ژئوپلیمر
Abstract
1- Introduction
2- Previous studies on geopolymer concrete
3- Taxonomy on geopolymer concrete research
4- Performance assessment methods
5- Assessing variables and assessing approaches
6- Structural tests for performance of geopolymer concrete
7- Performance design of geopolymer concrete
8- Conclusions and remarks
References
Abstract
Off late, the continuously depletion of the ozone layer and global warming issue have increased the awareness of the construction industries in using more eco-friendly construction materials. Against this background, geopolymer concrete has started to gain significant attention from the research scholars and construction practitioners, due to its advantageous in using by-product waste to replace cement and reducing greenhouse gas emission during its production. It also possesses better mechanical properties and durability compared to conventional concrete. Despite its advantageous, the use of geopolymer concrete in practical is considerably limited. This is mainly due to the lacking in the studies in terms of structural elements, design and application studies. This paper reviewed the material and structural performances of geopolymer concrete to identify the research gaps in this area for future research development. Analysis shown that geopolymer concrete can replace conventional concrete as they presented better mechanical properties, higher durability and more desirable structural performances compared with conventional counterparts. More studies are still needed for practical design standards and finally, the full scale studies on the structural elements should be established to ensure its feasibility in practical.
Introduction
Geopolymer is adjudged as the latest wave of cement, after gypsum cement and ordinary Portland cement (OPC). It has appeared to be one of the major construction material internationally. ‘Geopolymer’ can be referred as amorphous alkali aluminosilicate or alkali-activated cements [1]. Geopolymer concrete can be produced by polymerizing the aluminosilicates such as fly ash (FA), metakaolin (MK), slag (SG), rice husk ash (RHA), and high calcium wood ash (HCWA) through activation using alkaline solution. Hence the efficiency in producing geopolymer concrete is highly dependent on the activators as well as types of aluminosilicates resources [2]. In general, geopolymer is one of the inorganic polymers. It is amorphous rather than crystalline compared to other natural zeolitic materials [3]. The polymerization requires a considerably quick reaction of silica (Si)-alumina (Al) under alkaline condition which subsequently create three-dimensional polymeric chain of SiAOAAlAO bonds. Dissimilar to OPC or pozzolanic cements, geopolymer utilizes the polycondensation of silica and alumina and a high alkali content to attain compressive strength [4]. On the other hand, geopolymer incorporating OPC develops calcium silicate hydrates (C-S-H) as well as polycondensation of silica and alumina and a high alkali content to attain compressive strength. The following reactions occur during geopolymerization [5].