Discipline: Technology and Engineering
Subcategory: Materials Science
Cristian Rivera Perez - University of Puerto Rico, Mayaguez
Co-Author(s): Hildélix Soto, Miguel A. González, Alfer Castro, Marivette Rullán, Silvia T. Esteves, and O. Marcelo Suárez, University of Puerto Rico, Mayaguez
The modern construction industry seeks to develop and use of reliable technologies to accelerate project completion. These novel technologies must address environmental concerns as the excessive carbon footprint of this industry. In effect, numerous studies demonstrated that cement production is responsible for major carbon dioxide emissions To reduce this polluting effect while developing a high performance concrete (HPC, which is defined as one that reaches high structural resistance at an early curing age), numerous materials are being studied as partial cement substitutes. Fly ash (FA), a widely used recycled cementitious material, and nanostructured SiO2 (nS) particles, which bear pozzolanic and filler effects when incorporated into the mix, are examples of such materials. The present research evaluated the interaction between FA and nS to produce a HPC that reaches structural strength at an early age. Five concrete mix designs, engineered via statistical design of experiment, were tested according to pertinent ASTM standards. Penetration resistance tests were performed during the first 8 hours after mixing, to determine the concrete setting time. Compressive strength tests were also completed at 24, 48, and 72 hours to measure the concrete mechanical resistance at an early age. Our results demonstrated that the designed mixes containing FA and nS exhibited an early setting time by reaching a penetration resistance of at least 28 MPa before 8 hours after casting. In addition, a 40% compressive resistance increment was registered in mixes containing nS replacement. In closing, while FA proved to be an effective cementitious replacement, nS particles helped retain the material strength and accelerated the strength gain in early curing ages. Further studies will seek to implement rubber and plastic recycled materials as aggregates with the goal of making the concrete industry environmentally friendlier.
Funder Acknowledgement(s): O. Marcelo Suárez and Hildélix Soto.
Faculty Advisor: O. Marcelo Suárez, email@example.com
Role: I was involved with the mix design preparation and testing of mechanical properties. Also, I took part in the data analysis.