Effect of Natural Pozzolana on Physical and Mechanical Properties of Concrete

Table 2

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

W/C	Dose range (%)	Curing time (days)	Optimum strength			Type of NP	References
			Age (days)	Dose (%)	Strength (MPa)
0.40	0,15, 20, 25	2, 7, 30, 90, 365	7, 30, 90, 365	20	88.5, 91.2, 94.3, 105.6	Natural deposited ash	[99]
0.50	0, 5, 7.5, 10, 15	7, 28, 90	90	10	46.1	Diatomite	[13]
0.47	0, 5, 10, 15, 20	7, 28	7, 28	10	22.66, 26.67	Bentonite	[152]
0.55	0, 5, 10, 15, 20, 25	7, 28	7, 28	15	—, 31.65	Kaolin	[153]
0.40	0, 5, 10, 15, 20	7, 28, 56, 90	90	10	101.15	Kaolin	[53]
0.32	0, 5, 10, 15, 20	7, 28	7, 28	15	54.8, 72.7	Kaolin	[39]
0.40	0, 5, 10, 15, 20, 25, 30	3, 7, 28, 56, 90	28, 56, 90	15	—	Bentonite	[145]
0.55	0, 5, 10, 15, 20, 25, 30, 35	7, 14, 28, 56	14, 28, 56	10	32.76, 37.62, 42.67	Kaolin	[118]
0.35	0, 5, 10, 15, 20, 25	3, 7, 28	3, 7, 28	15	110	Natural deposited ash	[154]
0.48	0, 10, 15, 20, 30	7, 28	7, 28	20	22.18, 36.18	Kaolin	[155]
0.43	0, 4, 8, 12, 16, 20	3, 7, 28	3, 7, 28	12	16.83, 29.36, 47.016	Kaolin	[11]
0.50	0, 10, 20, 30	28, 56, 90, 180	180	20	57.5	Volcanic ash	[52]
0.67	0, 20, 30	7, 28	28	20	70.70	Volcanic ash	[83]
0.48	0, 5, 10, 15, 20	7, 28	7, 28	5	22.95, 26.69	Bentonite	[156]
0.30	0, 5, 10, 15, 20	28, 56, 90	28, 56, 90	15	—	Bentonite	[157]
0.50	0, 5, 10, 15, 20	3, 28, 90	90	20	—	Bentonite	[158]
0.40	0, 5, 10, 15, 20, 25, 30	3, 7, 28, 56, 90	28, 56, 90	15	53.2, 70.75, 73.80	Bentonite	[145]