Utilization of waste paper ash as supplementary cementitious material in C-25 concrete: Evaluation of fresh and hardened properties

Figures & data

Table 1. Properties of the sand used in the study

No	Description		Result
1	Silt content		4.54%
2	Moisture content		1.6%
3	Unit weight (Compacted):		1437.3 kg/m^3
4	Absorption capacity		2.04%
5	Specific gravity	Bulk	2.65
		Bulk (SSD)	2.70
		Apparent	2.80
6	Fines Modules		2.8

Table 2. Properties of coarse aggregate used in the study

No.	Test description			Test result
1	Maximum size			20 mm
2	Moisture content			1%
	Unit weight compacted			1591.35 kg/m^3
4	Absorption capacity			1%
5	Specific gravity:	Bulk		2.77
		Bulk (SSD)		2.80
		Apparent		2.86

Table 3. Consistency of blended cement paste

S/N	Composition	Code
1	OPC	WPA 0
2	95% OPC + 5% WPA	WPA 5
3	90% OPC + 10% WPA	WPA 10
4	85% OPC + 15% WPA	WPA 15
5	80% OPC + 20% WPA	WPA 210

Table 4. Chemical composition of waste paper ash (WPA)

Chemical Composition

SiO2

Al2O3

CaO

Fe2O3

MgO

Na2O

K2O

MnO

P2O5

TiO2

H2O

LOI

SO3

Amount (%)

29.20

2.65

50.88

1.78

0.86

0.30

<0.01

<0.01

0.67

<0.01

0.62

12.52

0.51

Table 5. Setting times of the blended cement paste

No	Concrete mix	Initial setting time (Min.)	Final setting time (Min.)
1	WPA 0	176	301.2
2	WPA 5	208	339.6
3	WPA 10	220	354
4	WPA 15	225	360
5	WPA 210	250	390

Figure 1. Consistency of blended cement paste

Figure 2. Workability of the concrete

Figure 3. Compressive strength of the concrete after 7 and 28 days

Table 6. The density of the concrete

No.	Concrete mix	Unit wt. (kg/m^3)	Reduction in (%)
1	WPA 0	2444.44
2	WPA 5	2419.95	1%
3	WPA 10	2392.88	1.12%
4	WPA 15	2359.79	1.4%
5	WPA 210	2311.52	2.05