Synthesis and Characterization of Porous Fly Ash-Based Geopolymers Using Si as Foaming Agent

Table 3

Synthesis parameters, compressive strength, and apparent density of Si foamed geopolymers.

Experiment	Si% w/w	R/Al	(Na/(Na + K))	Compressive strength (MPa)						Apparent density (g/cm^3)
				(1)	(2)	(3)	Mean	Maximum variation from mean (%)	Standard deviation
1	0.050	0.8	0.00	13.49	16.32	14.82	14.88	9.32	1.42	1.30
2	0.050	1.2	0.35	6.40	5.88	6.45	6.24	5.78	0.31	1.10
3	0.050	1.6	0.65	6.26	6.11	6.90	6.43	7.43	0.42	1.25
4	0.050	2.0	1.00	3.82	4.11	3.48	3.80	8.56	0.32	1.55
5	0.085	0.8	0.35	9.73	10.66	9.73	10.04	6.17	0.54	1.18
6	0.085	1.2	0.00	2.36	2.41	2.72	2.50	8.87	0.19	0.84
7	0.085	1.6	1.00	5.47	5.63	5.20	5.43	4.29	0.22	1.44
8	0.085	2.0	0.65	4.23	4.24	4.19	4.22	0.71	0.03	1.35
9	0.120	0.8	0.65	6.79	6.84	6.83	6.82	0.43	0.03	1.05
10	0.120	1.2	1.00	3.80	4.06	4.42	4.09	7.94	0.31	0.86
11	0.120	1.6	0.00	2.19	2.03	2.02	2.08	5.38	0.10	0.98
12	0.120	2.0	0.35	3.32	3.42	3.45	3.40	2.32	0.07	1.26
13	0.150	0.8	1.00	6.20	6.46	7.21	6.62	8.88	0.53	0.98
14	0.150	1.2	0.65	4.18	4.14	4.08	4.13	0.16	0.05	0.94
15	0.150	1.6	0.35	3.73	3.98	4.40	4.04	9.12	0.34	1.21
16	0.150	2.0	0.00	2.62	2.90	3.13	2.88	9.13	0.26	1.14