Human Hair as Fiber Reinforced Concrete for Enhancement of Tensile Strength of Concrete

FRC (Fibre Reinforced Concrete) is fibrous material which increases its structural integrity, resists explosive spalling in case of environmental affects, improves mix cohesion, improves ductility, reduces steel reinforcement requirements and reduces the voids due to good stiffness. It contains short discrete fibres that are uniformly distributed. Mostly, natural fibers are the waste material which may have negative impact on environment. Synthetic fibres include steel fibres and glass fibres but natural fibres are coconut fibres and human hair fibres which tend to vary the properties to concrete. In addition, the character of FRC changes with varying concrete, fibre material, geometries, distribution, orientation and densities. Hair fibre concrete gives a practical, cost-effective and convenient method to avoid cracks and deficiencies regarding strength and proper mixing ratio which occurs at a longer period. Fibres have been used to reduce plastic shrinkage and drying shrinkage in concrete. In some structural elements, fibrous concrete can be used to reduce the cost of structure. Different fibres are used to improve the tensile strength of concrete. Human hair are strong in tension. Hair fibres can be utilized as a strengthening material. Hair fibre is a non decayable matter and available at a cheap rate. Experiments have been performed on fibrous concrete cylinders containing various percentages of human hair which is 0, 0.5, 1 and 1.5% by the weight of cement. A total of seventy-two cylinders have been prepared with FRC having different %ages of hair content. Workability, compressive strength and split tensile strength have been checked at three curing ages i.e. 7, 14 and 28 days. This research will open a new wicket in the horizon of reuse of waste material efficiently in construction industry. This innovation in construction industry will save our natural resources and use fibre in productive and an effective approach.

INTRODUCTION [1]. It has little resistance to cracking. All structural members of building have been made by this like foundations, beams, slabs, columns and roofs [2]. By C oncrete is the most commonly used construction material which is the backbone of construction industry. It has low tensile strength and ductility

Human Hair as Fiber Reinforced Concrete for Enhancement of Tensile Strength of Concrete
adding fiber in concrete, properties of concrete can either be increased or decreased like compressive strength and tensile strength [3][4]. Concrete is fibrous material and addition of any kind of fibre in powder form or very small pieces will give the better results in wet areas where environmental effects deteriorate the buildings [5][6].
Fibre is a small piece of reinforcing material possessing certain properties. Addition of hair fibre to concrete affects the mechanical properties of concrete which depends on the percentage, length and type of fibre [7].
A good fibre must be compatible with binder. However, hair fibres are added in concrete to increase the mechanical properties of concrete [8][9]. Voids are left even after proper mixing of ordinary concrete. To overcome this issue fibres are used to fill the voids and reduced impact of cracking. Presence of fibrous material in concrete can enhance the durability of structure [10][11].
In our country, different catagories of human hair are present in different regions may be due to the environmental change as a waste material [12]. Thickness and stiffness can vary from person to person. It creates a lot of environmental issues and disturbs our sewerage system too [13][14].This is creating a negative impact on the environment [15][16]. The main objective of this study is to explore the possibility to use human hair as fibrous material to improve the mechanical characteristics of concrete.

Mix Design
Concrete strength 25MPa (4000 Psi) have been assumed.

Mixing Detail
Four types of mixes (M1, M2, M3 and M4) with different percentages of human hair fibre have been used in this research.

Casting
Casting of cylinders have been done after measuring the workability of concrete. Seventy-two cylinders in total (Nine cylinders for each type of hair fibre percentage) were casted in accordance with the (ASTM C-192), to test the cylinders at different ages (7, 14 and 28). The detail of the cylinders is given in Table 1.

Curing
Casted cylinders have been immersed in normal fresh water for curing. Three curing ages (7, 14 and 28 days) have been selected for four types of mixes (M1,M2,M3 and M4).

Treatment of Hair Fibre
Treatment of hair fibres are required before the mixing of concrete samples. Some steps have been followed. After drying, the hair can be stored.

Tests
Following tests are performed to check the mechanical characteristics of all mixes.

Workability
Results are tabulated on each type of mix as shown in below Table 2. Workability of all mixes are within the acceptable range.

TABLE 2. RESULTS OF SLUMP TEST (AUTHOR)
Workability of concrete for M1, M2, M3 and M4 mixes are shown in Fig. 6 which is between 40-60mm.

Compressive Strength
Compressive strengths are calculated by taking average of three tested samples for each type of mix at different ages. The results of compressive strength are shown in below Table 3 and graph has been plotted in Fig. 7.
Compressive Strength of concrete mix M1, M2, M3 and M4 are shown in Fig. 8 at the age specified in as above 4.2.

Split Tensile Strength
Tensile strengths are calculated by taking average of three tested samples for each type of mix at different ages. The results of tensile strength are shown in below Table 4 and graphs have been plotted in Fig. 8.

CONCLUSION
The following conclusions have been drawn from the experimental results.