*2.4.10 Scanning electron microscopy*

From the images of the scanning electron microscope (SCM) as seen in **Figures 8** and **9**, it is observed that the bricks are homogeneous, compact and free from defects such as holes and lumps.

**Figure 8.** *SEM image of GB-1.*

**51**

*Geopolymer Bricks Using Iron Ore Tailings, Slag Sand, Ground Granular Blast Furnace Slag…*

In this work a series of tests were carried out to study the strength and durability properties of the geopolymer bricks. Also field tests were conducted to check the

The compressive strength of the geopolymer bricks is more for the mix which has higher concentration of the alkaline solution, i.e. 10 M as compared to 8 M and

The compressive strength is minimum for the geopolymer bricks, which were having the least percentage of slag sand and with the highest percentage of iron ore tailings. The highest water absorption percentage obtained also showed the same pattern. The dimensionality test results were within the Indian Standard code recommendations. In falling test, failure of the geopolymer bricks was not severe and maximum pattern failures were restricted to mild edge failure, moderate edge

The efflorescence test conducted proved that the bricks were prone to efflorescence slightly. Thus, it satisfied the statement "Efflorescence shall not be more than Slight for Higher class bricks" as all the bricks belong to class AA category, the

The geopolymer bricks produced clear ringing sound when struck with another brick and proved to be sound and good. The bricks when subjected to hardness test by scratching with a nail did not leave any impressions on the surface and proved to

The structure test and the scanning electronic microscope (SCM) conducted on geopolymer bricks helped to understand the microstructure level of the bricks. The bricks are homogeneous, compact and free from defects such as holes, lumps etc.

The use of geopolymers proves to be an excellent replacement for cement and can be used as a stabilizer for bricks. Fly ash and ground granulated blast furnace

The compressive strength of geopolymer bricks with iron ore tailings, slag sand, fly ash, and GGBS increases with the increase in the molarity of the alkaline solution and increases with the increase in the percentage of slag sand. The minimum required compressive strength for geopolymer brick shall be achieved by all the

Iron ore tailings (IOT) and slag sand can be used for manufacturing stabilized

The field tests conducted on geopolymer bricks shows excellent results for being

adopting them for sustainable construction. Geopolymer bricks prove to be an

excellent replacement for fired bricks based on the studies conducted.

slab acts as excellent solid binders for the synthesis of geopolymers.

*DOI: http://dx.doi.org/10.5772/intechopen.81748*

The following are the key points of the discussions:

which has the highest percentage of Slag sand.

**3. Discussions**

quality of bricks.

failure and no failure.

highest category.

be sufficiently hard.

**4. Conclusion**

different mixes indicated.

geopolymer blocks of good quality and strength.

**Figure 9.** *SEM image of GB-4.*

*Geopolymer Bricks Using Iron Ore Tailings, Slag Sand, Ground Granular Blast Furnace Slag… DOI: http://dx.doi.org/10.5772/intechopen.81748*
