Evaluation of the Performance and Microstructure of Ecofriendly Construction Bricks Made with Fly Ash and Residual Rice Husk Ash

Table 4

FTIR characteristic bands identified in the FA and RHA powders and brick specimens shown in Figure 8.

Band	FA (cm^−1)	RHA (cm^−1)	P35U00 (cm^−1)	P35U10 (cm^−1)	P35U20 (cm^−1)	P35U30 (cm^−1)	P35U40 (cm^−1)	Characteristic bands
A	3412	3447	3464	3466	3466	3466	3464	O–H stretching (H2O) [24, 26, 27]
B	1620	1611	1692	1692	1692	1692	1690	O–H bending (H2O) [24, 26, 27]
C	—	—	1462	1464	1462	1462	1462	Si–O/Al–O stretching [24, 26]
D	1096	1096	1078	1084	1086	1088	1091	Si–O/Al–O stretching [24, 27, 28]
E	795	791	779	779	791	791	789	Si–O–Si stretching quartz [26, 28]
F	—	621	619	621	619	619	619	Zeolites [26, 28]
G	459	473	465	465	469	471	471	O–Si–O bending (SiO4) [24, 27, 28]