Optimization of compressive strength of concrete with pig-hair fibers as fiber reinforcement and green mussel shells as partial cement substitute

• Main Authors: Lejano, Bernardo A., Gagan, Jayvee L.
• Format: text
• Published: Animo Repository 2017
• Subjects: Fiber-reinforced concrete—Compression testing; Waste products as building materials; Shells; Civil Engineering
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/2955
• Institution: De La Salle University

The feasibility of different waste materials as substitute to the main components of concrete is attracting attention nowadays. In relation to that, this study focuses on determining the effects of combining two waste materials namely, pig-hair fibers (PHF) as fiber reinforcement and crushed green mussel shells (GMS) as partial cement substitute to the properties of concrete. Response Surface Methodology (RSM) was used to model the relationship between the response and the factors considered. Using central composite design (CCD) to establish the design of experiment, the researchers was able to reduce the required number of experimental runs to 20 from a total of 27 runs for 3 level full factorial experimental program that is common for responses with nonlinear behavior. Optimization was conducted to determine the optimum amount of PHF and GMS in concrete that could yield maximum compressive strength while keeping the workability at an acceptable level. As for the results, an increase in compressive strength of concrete was recorded with the incorporation of PHF and GMS to concrete. However, decrease in workability was experienced due to the amount of fiber reinforcement present in the mix. Results of RSM suggested an optimum combination of 0.70% PHF content and 7.81% GMS partial cement substitute at 0.47 water-cement ratio (w/c) to achieve 27.40 MPa and 2.78 MPa compressive and tensile strength respectively with a minimum recommended slump of 25 mm for concrete beams and columns as per ACI. Based on these results, PHF-GMS concrete could be used in structures not requiring compressive strength above 28 MPa. With the use of GMS as a partial cement substitute, it could reduce the overall cement requirement for a project thus incurring savings and most importantly promotes the use of environment friendly materials. © Int. J. of GEOMATE. All rights reserved.