Proposed alternative reinforced concrete pipe culverts with nylon fibers

• Main Authors: Bellosillo, Paolo S., Manuel, Jeffrey C.
• Format: text
• Language: English
• Published: Animo Repository 2008
• Subjects: Pipelines > Maintenance and repair; Reinforced concrete culverts > Design and construction; Pipe, Concrete; Civil Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/11472
• Institution: De La Salle University

The DPWH specifies ASTM Class 2 Standard RC Pipes to be used in the country. For a 610-mm diameter pipe, the standard design for ASTM uses 7 hoops of steel as its main reinforcing bars. However, some manufacturers are proposing to reduce the number of steel hoops in concrete pipes in order to save money. This produces weaker strengths of concrete pipes than the standard design specified by the DPWH. In order to attain the strength of the ASTM Concrete Pipes using only 5 hoops of steel, nylon fibers were added to the concrete mixture as additional reinforcement. This research paper tests whether adding nylon fibers to concrete pipes with only 5 hoops of steel reinforcement can reach the strength of the ASTM RC Pipes with 7 hoops of steel. This paper also investigates the effects of adding nylon fibers to concrete in terms of its compressive and tensile strengths. Our tests show that adding nylon fibers to the dry concrete mixture increases the strength of the concrete in terms o compression and tension. For the wet concrete mixture, which is the typical mixture for RC pipes, adding nylon fibers decreases the compressive strength of the concrete. In the case of the concrete pipes, adding nylon fibers to the RC pipes with 5 hoops increases its strength, but it still cannot reach the strength of the ASTM RC pipes with 7 hoops of steel. Using the ASTM standards for the construction of concrete pipes is still the best way to go, despite the expenses. The safety of the public must be our number one priority, not money.