Evaluation of the Effects of Combining Pig-Hair Fiber as Fiber Reinforcement and Green Mussel Shells as Partial Cement Substitute to the Properties of Concrete

The feasibility of different waste materials as substitutes to the main components of concrete is attracting attention nowadays. This study mainly focuses on determining the effects of combining two waste materials i.e. pig-hair fiber and crushed green mussel shells to the properties of concrete. The pig-hair fibers (PHF) are used as fiber reinforcement to concrete and the crushed green mussel shells (GMS) are used as a partial cement substitute. With the use of statistical analysis software, Response Surface Methodology (RSM), the design of an experimental program was generated. The result of the experimental program is used to investigate the interaction between these two materials and their effect on the compressive strength of the concrete. RSM was used to determine the optimum amount of PHF and GMS that can be incorporated to the concrete to achieve the highest compressive strength while keeping the workability of the concrete at an acceptable level. In this study, the Central Composite Design (CCD) is used to fit the model for the materials under study. A total of 12 experimental runs were used in this study, with 3 levels assigned to each factor. For PHF, 3 levels (0.6%, 0.8% & 1.0%) per volume of concrete of fibers were used. Also, 3 levels (5%, 10% & 15%) of partial cement substitute were used for GMS. These combinations were incorporated in different water-cement ratio of 0.4, 0.5 and 0.6. The effects of these factors and their interaction were investigated and analyzed. Results show that addition of these materials has a significant effect on the resulting properties of concrete. An increase in the compressive strength of concrete is recorded with the incorporation of these materials. However, decrease in workability too are experienced due to the amount of fiber reinforcement present in the mix. Results of RSM suggests an optimum combination of 0.70% PHF content, 9.09% GMS partial cement substitute and at 0.50 w/c ratio to achieve 26.73 MPa with an acceptable slump of 25 mm.