Effect of Natural Pozzolana on Physical and Mechanical Properties of Concrete

Table 4

Optimum NP dose recorded for improvement of flexural strength by different researchers.

W/C	Dose range (%)	Curing time (days)	Optimum strength			Type of NP	References
			Age (days)	Dose (%)	Strength (MPa)
0.47	0, 5, 10, 15, 20	7, 28	7, 28	5	3.0, 3.88	Bentonite	[152]
0.40	0, 5, 10, 15, 20	7, 28, 56, 90	56, 90	15	8.90, 8.85	Kaolin	[53]
0.32	0, 5, 10, 15, 20	28	28	15	7.2	Kaolin	[39]
0.48	0, 10, 15, 20, 30	7, 28	28	20	3.86	Kaolin	[155]
0.48	0, 5, 10, 15, 20	7, 28	7, 28	5	17.84, 20.27	Bentonite	[156]
0.30	0, 5, 10, 15, 20	28, 56, 90	28, 56, 90	15	19, 19.5, 20	Bentonite	[157]
—	0, 10, 20, 30	1, 2, 14, 28, 90, 180	28, 90, 180	10	9.65, 10.03, 10.54	Volcanic ash	[61]