Groundnut Shell Ash as Partial Replacement of Cement in Concrete

 

Dr. M. Vijaya Sekhar Reddy¹*, K. Sasi², K. Ashalatha², M. Madhuri²

¹Head of the Department and Assistant Professor, Department of Civil Engineering,

Srikalahasteeswara  Institute of Technology, Srikalahasti, Andhra Pradesh, India

²Lecturers, Department of Civil Engineering, Srikalahasteeswara Institute of Technology,

Srikalahasti, Andhra Pradesh, India

 

Abstract:

Ordinary Portland cement is recognized as a major construction material throughout the world. Researchers all over the world today are focusing on ways of utilizing either industrial or agricultural waste, as a source of raw materials for industry. This waste, utilization would not only be economical, but may also result in foreign exchange earnings and environmental pollution control as industrial wastes, such as blast furnace slag, sugar cane bagasse ash, ground nut shell ash, fly ash and silica fume are being used as supplementary cementing materials (SCMs). The utilization of industrial and agricultural waste produced by industrial process has been the focus of waste reduction research for economical, environmental, and technical reasons. The present study is aimed at ground nut shell ash (GSA), with partial replacement of cement. The replacement is done at various percentages like 0%, 5%, 10%, 15% and its effect on properties of concrete was investigated. Fresh and hardened properties were exercised with various replacement levels. The study indicated that ground nut shell ash can effectively be used as cement replacement (up to 10%) without substantial change in strength.

 

 

 

INTRODUCTION:

The continuous increase in the price of Portland cement is attributed to the insufficient production rate of the raw materials when compared with the demand rate in the construction industries. Due to increasing industrial and agricultural activities, tones of waste materials are deposited in the environment with little effective method of waste managing or recycling. Some of these deposits are not easily decomposed and the accumulation is a threat to the environment and people at large.

Some of these waste materials are rice husks, maize combs, snail shells, palm-kennel shell, coconut shell, saw dust, groundnut shell etc.

 

Ground nut shell ash was partially used cement in concrete. Thus, the possible use of agriculture waste (such as Ground nut shell ash-GSA) will considerably reduce the cost of construction and as well as reduce or eliminate the environmental hazards caused by such waste.

 

An investigation was done by Okpala D.C et al., illustrated that the paper on partial replacement of ordinary Portland cement (OPC) with Bambara groundnut shells ash (Bgsa) in concrete. The ash contained 10.91% CaO, 2.16% Fe₂O₃, 4.72% MgO, 33.36% SiO₂, 1.75% Al₂O₃, 16.18% K₂O, 9.30% Na₂O, 6.40% SO₃, 6.02% CO₃ and 9.20% HCO₃. 10%, 20%, 30%, 40%, 50% and 0% ash was used in the mix to replace cement. The strength of cement/ash concrete increased with curing period but decreased with increasing ash percentage. The highest strength was 31.24 N/mm² and 20.68 N/mm² at 28 days for 0% and 10% ash respectively. Substitution of cement with ash in concrete formation was relatively possible not exceeding 10%, though the strength of OPC/BGSA concrete was lower than that of 100% cement, thus it can be used for light load bearing elements [1].  

 

An investigation was done by Nwofor and Sule, et al., (2012), based on the use of considerable volume of groundnut shell ash as the partial replacement for cement in concrete production. A total of 100 specimens of the GSA/OPC concrete were cured in cubes of 100mm dimension for 7, 14, 21 and 28 days and the compressive strength and density determined. The utilization of ground nut shell ash reduces the environmental problems and also replacement level of (0-40%) gives high compressive strength. A percentage replacement of 10% is suggested for sustainable construction, especially in mass concrete constructions[2].

 

An investigation was done by Mahmoud. H. et al., (2012), the production of sandcrete blocks using groundnut shell ash (GSA) as cement replacement was investigated.  Six number of sandcrete blocks were cast for each replacement levels (0, 10, 20, 30, 40, and 50 percentage) with GSA. The blocks were cured and crushed at 7, 14, 21, and 28 days. The results show that the compressive strength ranges from 4.50 N/mm² to 0.26 N/mm².The optimum replacement level was achieved at 20% with a corresponding strength of 3.58 N/mm² [3].  

 

An investigation was done by Sadaa. B. H et al., (2013), based on the suitability of groundnut shell as a constituent material in concrete was investigated by replacing proportions by volume of fine aggregate (river sand) with groundnut shells. Groundnut shells were used to replace fine aggregate at 0, 5, 15, 25, 50 and 75% replacement levels. Compressive strength values of the concrete cubes were evaluated at 28 days at different percentage replacement levels obtaining a range of values of 34.37, 40.59, 21.33, 17.78, 12.44, 7.56 N/mm²[4].

 

MATERIALS USED IN THE PRESENT STUDY:

Cement:

Ordinary Portland cement Zuari-53 grade conforming to IS: 12269-1987 [5] were used in concrete. The physical properties of the cement are listed in Table 1.

 

Aggregates:

A crushed granite rock with a maximum size of 20mm and 12mm with specific gravity of 2.72 was used as a coarse aggregate. Natural sand from Swarnamukhi River in Srikalahasti with specific gravity of 2.60 was used as fine aggregate conforming to zone- II of IS 383-1970 [6]. The individual aggregates were blended to get the desired combined grading.

 

Water:

Potable water was used for mixing and curing of concrete cubes.

 

Supplementary Cementing Materials:

Ground Nut Shell Ash:

Groundnut shell used for this research was obtained from Groundnut mill. The shells were collected in bags and transported to site, where the burning and grinding were carried out. The ash was obtained by burning the groundnut shells on an iron sheet in the open air under normal temperature. Consequently, the ashes were collected in bags and were taken to the Concrete and Structural Laboratory of the Department of Building. The sieve analysis and the specific gravity were carried out on GSA.

 

VARATHANE 100:

VARATHANE 100 is a two part solvent-free, low viscosity high tensile strength polyurethane based system designed to form a strong permanent bond and seal in cracks in dry, damp or wet concrete and masonry.

·        Solids contents (%) : 100. 

·        Pot life @ 25°C: 30 to 45 minutes.

·        Minimum temperature for hardening: 0^o C. 

·        Tensile Strength:  2.5 N/mm². 

·        Extensibility (%): 80.

 

 

Table 1. Physical Properties of Zuari-53 Grade Cement

Sl. No.	1	2	3	4	5
Properties	Specific gravity	Normal onsistency	Initial setting time	Final setting time	Compressive strength (Mpa)
Values	3.15	32%	60 min	320 min	3 days	7 days	28days
					29.4	44.8	56.5

 

 

 

Table 2. Physical Properties of Ground Nut Shell Ash.

S.No	Physical properties of cement	Results
1	Specific gravity	3.2
2	Standard consistency (%)	34%
3	Initial setting time (min)	135
4	Final setting time (min)	330

 

RESULTS AND DISCUSSIONS:

In the present work, proportions for concrete mix design of M30 were carried out according to are10262-2009 [7] recommendations. The mix proportions are presented in Table 3.

Table 3. Mix Proportion for M₃₀ Concrete.

	Cement	Secondary Cementing Materials	Fine aggregate	Coarse aggregate (20mm 20% & 12.5mm 80%)	Water
Composition in Kg/m2	350	63	706	1117	186
Ratio in %	1		1.709	2.704	0.45

 

1. Workability Test (Slump Cone Test):

The workability test results are presented in Table.4 and Fig 1.

 

Table 4: Workability Test (Slump Cone Test)

Replacement of Ground Nut Shell Ash with Cement (%)	Workability (slump in cm)
Control Mix	24
Mix 1	26
Mix 2	28
Mix 3	27

 

 

Fig 1: Variation of Workability for Different Trail Mixes

 

2. Compressive Strength:

The tests were carried out as per IS: 516-1959 [8]. The 150mm size cubes of various concrete mixtures were cast to test compressive strength. The cubes specimens after de-moulding were stored in curing tanks and on removal of cubes from water the compressive strength were conducted at 7days, 28days and the results are represented in Table 5 and Fig 2. The test results were compared with controlled concrete.

 

Table 5. Compressive Strength for Different Trail Mix

Percentage Replacement of  Ground Nut Shell Ash.	Compressive  Strength N/mm2
	7 Days	28 Days
Control mix	32.50	38.60
Mix 1	35.00	39.20
Mix 2	38.00	41.33
Mix 3	32.00	38.20

 

Fig 2: Variation of Compressive Strength for Different Trail Mixes

 

3. Split Tensile Strength:

The tests were carried out as per IS: 5816-1999 [9].The variation of split tensile strength at the age of 7 days and 28 days with optimum percentage of ground nut shell ash was given below. It was observed that the maximum split tensile strength was obtained for Mix 2 with 10 % of ground nut shell ash. The test results are represented in Table 6 and Fig 3. The test results were compared with controlled concrete.

 

Table 6. Split Tensile Strength for Different Trail Mix

Percentage Replacement of Ground Nut Shell Ash.	Split Tensile Strength N/mm2
	7 Days	28 Days
Control mix	2.61	3.31
Mix 1	2.91	3.56
Mix 2	3.45	4.15
Mix 3	2.58	3.26

 

4.  Flexural Strength:

The variation of flexural strength at the age of 7 days and 28 days with optimum percentage of ground nut shell ash was given below. It was observed that the maximum flexural strength was obtained for Mix 2 with 10 % of ground nut shell ash. The test results are represented in Table 7 and Fig 4. The test results were compared with controlled concrete.

 

 

Fig 3: Variation of Split Tensile Strength for Different Trail Mixes

 

Table 7. Flexural Strength for Different Trail Mix

Percentage Replacement of Ground Nut Shell Ash.	Flexural Strength N/mm2
	7 Days	28 Days
Control mix	3.01	3.59
Mix 1	3.20	3.72
Mix 2	4.12	4.70
Mix 3	2.49	3.05

 

 

Fig 4: Variation of Flexural Strength for Different Trail Mixes

 

CONCLUSIONS:

The maximum compressive strength for seven and 28 days curing period are 38.00 and 41.33 N/mm² with 10% replacement of cement by ground nut shell ash.

 

The results depicts that the maximum split tensile strength for seven and 28 days curing period are 3.45 and 4.15 N/mm² with 10% replacement of cement by ground nut shell ash.

 

Also the experimental results reveals that the maximum flexural strength for seven and 28 days curing period are 4.12 and 4.70 N/mm² with 10% replacement of cement by ground nut shell ash.

 

It is observed that the strength results are showing decreasing trend beyond 10% replacement of cement by ground nut shell ash. So the optimum percentage of groundnut shell replacement can be chosen at 10%.

 

The use of ground nut shell can reduce the cost of construction as well as eliminates the environmental hazards.

 

REFERENCES

1.       Okpala D.C., Husk R. (1987), Ash as Partial Replacement for Cement in Concrete, the Nigeria Society of Engineers Annual Conference Proceedings, Port Harcourt, November 1987.

2.       Nwofor, T. C. and Sule, S. (2012). Stability of Groundnut Shell Ash and Ordinary Portland cement Concrete in Nigeria. Advances in Science Research, vol. 3(4), pg. 2283 – 2287.

3.       Mahmoud, H., Belel, Z. A. and Nwakaire, C. (2012). Groundnut Shell Ash as a Partial Replacement of Cement in Sandcrete Blocks Production. International Journal of Development and Sustainability, Vol. 1(3), pg. 1026 - 1032.

4.       Sadaa, Y.D. Amarteyb, S. Bakoc B.H (2013) An Investigation into the Use of Groundnut Shell As Fine Aggregate Replacement. Department of Civil Engineering, Ahmadu Bello University, Zaria, Nigeria, Vol 32, No 1, March, pg 54-60.

5.       IS: 12269-1987, Specification for 53 Grade Ordinary Portland Cement, Bureau of Indian Standards, New Delhi, India, 1989.

6.       IS: 383-1970: specifications for coarse and fine aggregates for natural sources of concrete, Bureau of Indian standards, New Delhi.

7.       IS: 10262-2009: Concrete Mix Proportioning-guidelines, Bureau of Indian Standards, New Delhi.

8.       IS: 516-1959: Methods of tests for strength of concrete, BIS, New Delhi.

9.       IS: 5816-1999, Splitting tensile strength of concrete, BIS, New Delhi.

 

 

 

 

Accepted on 21.09.2017      ©A&V Publications All right reserved